Prescribed Exercise to Reduce Recidivism After Weight Loss Pilot (PREVAIL-P)
Phase: NA
Conditions: Obesity, Sedentary Lifestyle, Insulin Resistance
Sponsor: East Carolina University

Title of Study: Prescribed Exercise to Reduce Recidivism After Weight Loss Pilot (PREVAIL-P) study: 
Clinical Trials ID: NCT03685123 
Document date: 2-16-18 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Specific Aims: Achieving clinically significant weight loss (CWL) of 5-10% has been shown to improve 
important cardiometabolic risk factors in overweight and obese adults (e.g. insulin sensitivity, dyslipidemia, 
systemic inflammation, blood pressure). However, only 20% of individuals achieve weight loss maintenance 
and even mild weight regain (2-6%) is associated with regression of risk factors toward pre-weight loss levels. 
Obtaining high amounts of physical activity (PA) are critical for successful weight loss maintenance. However, 
the current recommendation for the amount of PA needed to maintain CWL (200-300 min per wk. at moderate 
intensity) was derived primarily from retrospective studies where PA level was determined by questionnaire 
and other important design features were not included (e.g. standardization/supervision of exercise levels, 
randomization after clinically significant weight loss). The American College of Sports Medicine position stand 
on Physical Activity and Weight Maintenance states that “there are no correctly designed, adequately 
powered, energy balance studies to provide evidence for the amount 
of physical activity to prevent weight regain after weight loss.” This is 
important given that increased compensation for weight loss (losing less 
weight than predicted) has been observed with high levels of aerobic 
exercise training (Figure). Similarly, changes in cardiometabolic risk factors 
(e.g. insulin sensitivity, lipids, arterial stiffness) have rarely been reported 
across PA levels during weight maintenance, which may be more influential 
on cardiovascular disease risk status compared to only evaluating changes 
in weight. Thus, there is a need for tightly controlled prospective 
interventions to test the extent to which the weight maintenance physical 
activity recommendations improve weight maintenance and cardiometablic 
risk factors compared to other exercise levels.  
 
The Prescribed Exercise to Reduce Recidivism After Weight Loss Pilot (PREVAIL-P) study will evaluate 
the effect of aerobic exercise training amount on weight maintenance following CWL. In concert with goals of 
the R56 mechanism, this one-year project will provide data to support a future R01 application where 
overweight and obese (BMI: 25-40 kg/m2) men and women (18-65 years old) complete an OPTIFAST diet 
(7%-10% weight loss). Participants that obtain CWL will be subsequently randomized to aerobic exercise 
training consistent with the minimum physical activity guidelines (~150 min of moderate intensity exercise) or 
weight maintenance guidelines (200-300 min per wk. at moderate intensity) for 9 additional months. Therefore, 
we have proposed 2 studies to address the feasibility of this intervention and demonstrate differences in weight 
and cardiometabolic health parameters to justify the funding of a future R01 proposal. In both studies, exercise 
training will be supervised by study staff to confirm exercise-related caloric expenditure. Non-exercise physical 
activity will be assessed objectively through accelerometry during the entire intervention.  
 
Specific Aim 1: To demonstrate the efficacy of the weight loss program in producing CWL and 
retention/adherence of the exercise intervention. Overweight and obese adults (N=39) will participate in an 
OPTIFAST weight loss program and supervised aerobic exercise training (~550 MET min. per week.) for 10 
weeks. Participants who obtain CWL will be subsequently randomized to 18 weeks of aerobic training 
consistent with the minimum physical activity recommendations (~550 MET min per week.) or weight 
maintenance guidelines (~970 MET min per week). We will evaluate the percentage of participants that obtain 
at least 7% weight loss following OPTIFAST treatment, retention rates in the weight loss program, adherence 
to exercise levels, and changes in weight and cardiometabolic risk factors in response to the intervention.  
 
 
Specific Aim 2: To test the hypothesis that exercise levels consistent with weight maintenance 
recommendations leads to greater weight maintenance after CWL compared to the minimum physical activity 
recommendation levels. Overweight and obese adults (N=30) enrolled in VIDANT health’s OPTIFAST program 
and have achieved at least 7% weight loss will be randomized to 36 weeks of aerobic exercise training 
consistent with the minimum public health guidelines for physical activity (~550 MET min. per week.) or weight 
maintenance levels (~970 MET min per week). We will evaluate the effect of the intervention on weight 
(primary) as well as main secondary measures (e.g. body fat, visceral fat, lipids, lipoprotein particles size/class, 
insulin sensitivity, blood pressure, arterial stiffness, systemic inflammation, fitness, and quality of life). The 
aforementioned cardiometabolic risk factors were selected because they can be improved specifically by 
weight loss and thus may respond differently to weight maintenance or regain.  
 
 
The PREVAIL-P study will provide data on the effect of exercise level on weight maintenance and 
cardiometabolic risk factors after CWL. This study has high public health importance and will yield 
meaningful results to justify additional funding for this clinical trial as an R01 application. 
Martin et al. Weight compensation with 
different exercise levels (preliminary 

1. Background and Significance: Clinically significant weight loss (CWL) is defined as a weight loss of at 
least 5%-10% of initial body weight and has been shown to elicit improvements in important cardiometabolic 
risk factors (e.g. lipids, blood pressure, insulin resistance) [1]. However, the vast majority of individuals (80%) 
[2] are not able to maintain CWL, and the recidivism back to the initial weight is not only associated with 
increased cardiovascular disease (CVD), but also regression in CVD risk factors [3, 4]. Potential rationales for 
the high prevalence of weight regain after the initial weight loss include increases in appetite hormones (e.g. 
ghrelin), decreases in anorexigenic hormones (e.g. Leptin, GLP-1), reductions in compliance with self-
monitoring/weighing habits, and decreases in resting metabolic rate with weight loss [3]. Importantly, it has 
been well established that obtaining a high amount of physical activity is a critical factor for the maintenance of 
CWL [1]; however the actual level of physical activity needed to optimally promote weight maintenance 
following CWL has not been adequately quantified or tested in a prospective intervention. In the American 
College of Sports Medicine (ACSM) position stand (Appropriate Physical Activity Strategies for Weight Loss 
and Prevention of Weight Regain for Adults) [1] a committee of experts attempted to determine the amount of 
physical activity that was necessary to promote weight maintenance after CWL. The committee determined 
that approximately 200-300 minutes per week of physical activity at a moderate intensity was necessary to 
promote weight maintenance. These levels are based on data from studies from the National Weight Loss 
Registry and retrospective analyses from prospective studies where the amount of physical activity was 
quantified primarily through questionnaires [5-9]. The ACSM position stand emphasized that although this was 
the best estimation that could be determined based on the limited available literature, “major flaws” existed in 
the design of these studies”.  Further, the position stand expressed the need for more research as it states, 
“there are no correctly designed, adequately powered, energy balance studies to provide evidence for 
the amount of physical activity to prevent weight regain after weight loss.”  
 
The primary limitations of the physical activity amount and weight maintenance literature are listed below: 
• 
Many studies were retrospective, meaning that physical activity levels were self-selected [5-7] 
• 
Physical activity levels were quantified through subjective physical activity questionnaires  [5-7, 10-12], 
which have reduced accuracy and may be over-reported compared to objective measures [13-15] 
• 
Lack of randomization to different physical activity levels after the attainment of CWL  
• 
Physical activity and weight maintenance was evaluated across a wide range of PA levels. Studies 
evaluating physical activity level and weight maintenance often use tertile analyses which collapse 
many physical activity levels together (e.g. <150 (low), 150-250 (moderate), >250 min. per week (high). 
Thus, if level of exercise is being compared to weight maintenance and one of the categories is <150 
minutes per week. This means that an individual with 2 min. per week and 145 min. per week are both 
categorized as having low physical activity, which are very different exercise levels.    
• 
 Little data are available on how physical activity levels after CWL affect clinically relevant traditional 
and non-traditional cardiometabolic risk factors 
To further highlight the need for a prospective intervention on physical 
activity amount and weight maintenance, previous exercise studies without 
a weight loss component have shown that there is greater amount of 
weight loss compensation (losing less weight than predicted) with very high 
levels of aerobic training. Church et al. [16] observed greater amounts of 
weight compensation in obese postmenopausal women after 6 months of 
aerobic exercise at  around ~140 min. per week compared to ~193 min. per 
week (Figure 1A). Similarly, preliminary data from the E-MECHANIC study 
(Co-PI: Corby Martin [consultant on this grant]) show a greater amount of 
weight compensation after 6 months of aerobic training in overweight and 
obese adults exercising at ~250 min. per week) compared to ~100 min. per 
week) (Figure 1B). Weight compensation occurred in 90% of exercisers in 
the 250 min. per week group. Thus, it possible that weight compensation 
may be an issue for those exercising at weight maintenance guidelines 
after CWL, but at this time there are no prospective interventions, which 
have the necessary design components to fully study this issue. 
While weight maintenance is an important endpoint, it may be 
equally or more important to determine the impact of different exercise 
levels after CWL on major independent cardiovascular and metabolic risk 
factors. Weight loss alone has notable effects on lipids (LDL-C: ~↓5 
mg/dL, triglycerides: ~↓15 mg/dL, HDL-C: ~↑2-3 mg/dL)  [17-19], but also 
Figure 1. Weight compensation and 
exercise level in DREW (Panel A) and 
E-MECHANIC (Panel B) studies  

other clinically relevant cardiometabolic risk factors such as insulin sensitivity [20, 21], arterial stiffness [22, 23], 
c-reactive protein [24, 25] and resting blood pressure [18, 19]. Independently, aerobic exercise training has a 
much more limited effect on lipids [26], but has been shown to have independent effects on insulin sensitivity 
[27, 28], arterial stiffness [29-31], lipoprotein particle size [32] and absolute fitness [33, 34]. It also important to 
highlight that cardiorespiratory fitness and change in cardiorespiratory fitness [35]) are independent risk factors 
for cardiovascular disease [35-37]. Higher levels of  aerobic training improves fitness in a dose response 
manner [33]. Thus, along with prevention of weight regain, exercising at weight maintenance guidelines (200-
300 minutes of moderate physical activity per week) has the potential to maintain CWL more effectively than 
lower levels of exercise, but also offer more cardiometabolic health benefits. This is particularly important given 
that even mild weight regain (2-6%) [4] has been associated with regression in major cardiovascular risk 
factors such as total cholesterol [38, 39], LDL cholesterol [39, 40], triglycerides [38, 41, 42], blood pressure [41-
43], glucose [38, 39, 44] and insulin levels [40, 43]. Along with cardiovascular complications, quality of life is 
lower in obese compared to normal weight individuals [45-47]. QOL improves with aerobic training in a dose 
response manner [48] and also improves with weight loss [49-51] and is another important variable to 
understand the health benefits of the weight maintenance physical activity recommendations.    
Thus, there is value in understanding the impact of aerobic training to counter the negative 
cardiovascular and behavioral impacts of weight regain after weight loss. The clinical and public health 
implications of this research will provide physicians, clinicians and health professionals greater information on 
how to help their patients maintain their weight loss and what the direct impact of these exercise levels are on 
major traditional and non-traditional cardiometabolic variables.                                                                                          
 
2. Innovation: The Prescribed Exercise to Reduce Recidivism After Weight Loss Pilot (PREVAIL-P) study will 
provide data to support a large-scale trial on the impact of aerobic exercise training level on weight 
maintenance and cardiometabolic risk factors. To address the design limitations of previous studies on 
physical activity level and weight maintenance, the PREVAIL-P study will: 1) Directly supervise exercise 
training to confirm exercise-related energy expenditure (indirect calorimetry will be used to enhance the 
accuracy to exercise caloric expenditure). 2) Non-exercise physical activity will be objectively measured during 
the entire intervention through accelerometry. 3) Randomizing participants to study groups after clinically 
significant weight loss. 4) Obtain data on cardiovascular risk factors, which have rarely been reported in the 
weight maintenance literature (as much of the focus is solely on weight). This R56 application and subsequent 
R01 application will help clarify how aerobic exercise level impacts weight maintenance, but also clinically 
relevant traditional (brachial blood pressure, lipids, insulin sensitivity, body fat) and non-traditional risk 
cardiometabolic risk factors (central blood pressure, arterial stiffness, lipoprotein particle size/class and 
fitness), which have both high clinical and public health relevance. These studies have the potential to impact 
future obesity and physical activity guidelines for weight maintenance.  An innovative aspect of our design for 
this initial one-year period is that we will: 1) demonstrate efficacy and the utility of our experimental design and 
2) provide a participant pool for future studies on physical activity and weight maintenance.  
 
3. Approach: 
 
Rationale for the studies proposed: Since the R56 mechanism has one year of research funding, a full study 
on weight loss (12 weeks) and subsequent exercise/physical activity intervention typical of weight maintenance 
studies (9 to 12 months) is not possible. However, we believe that we can obtain the necessary data for an 
R01 on this topic by: 1) Demonstrating that the study team can successfully deliver the weight loss component 
of the trial with high achievement of CWL in overweight/obese participants and subsequent delivery of the 
exercise training intervention (albeit shorter than a full weight maintenance trial). 2) Obtaining a sample of 
participants that have achieved 7%-10% weight loss at the beginning of the award from participants completing 
a weight loss program and randomize them to study groups and subsequently provide data to support our 
experimental approach. 
 
Study 1: To demonstrate the ability of the study team to deliver the weight loss program producing clinically 
significant weight loss and retention/adherence of the exercise training intervention: 
 
Brief Description: We will recruit 39 sedentary overweight with elevated metabolic risk (e.g. pre-diabetes, 
hypertension, dyslipidemia, elevated waist circumference) and obese (Class I and II) adults (age: 18-65 yrs., 
BMI: 25-39.9 kg/m2) from the Pitt county, NC area. We selected these criteria based on the 2013 
AHA/ACC/TOS Guidelines for the Management of Overweight and Obesity in Adults [19]. We will exclude 
individuals with diagnosed T2D or significant cardiovascular diseases, and/or those taking medications or have 
conditions that confound weight loss or regain (e.g. hypo/hyperthyroidism [both medicated or untreated], 
bariatric surgery, etc.).  Participants will undergo an OPTIFAST weight loss program and supervised aerobic 

exercise training (~550 MET min.) for 10 weeks. Participants who obtain clinically significant weight loss (≥7%) 
will be subsequently randomized to 18 weeks of aerobic training consistent with the minimum physical activity 
recommendations (PA-REC) (~550 MET min.) or weight maintenance recommendations (WM-REC, ~970 MET 
min.). We will evaluate the percentage 
of participants that obtain at least 7% 
weight loss following OPTIFAST 
treatment, retention rates in the weight 
loss program and the study as whole, 
and adherence to exercise levels of 
the participants. We will also evaluate 
cardiovascular risk factor changes due 
to the intervention. A flow diagram for 
Study 1 is shown in Figure 2. 
 
 
 
Rationale for inclusion/exclusion: For the inclusion criteria, we made several key decisions in regard to BMI 
levels, postmenopausal women, and those with advanced cardiovascular diseases/type 2 diabetes. We 
decided to include individuals who were overweight (with an indication of increased risk). This was based on 
the 2013 AHA/ACC/TOS Guidelines for the Management of Overweight and Obesity in Adults [19], which 
provided recommendations for those who needed to lose weight. Since the secondary aims of the study focus 
on changes in CVD risk factors, it is necessary to recruit a population that has some derangement in these 
factors at baseline. We decided to exclude participants with morbid obesity (BMI ≥ 40 kg/m2) to maintain some 
consistency between absolute (kg) and relative weight loss (%) across participants and these individuals may 
have joint/gait issues that  may affect long term exercise [52]. In regard to those with established CVD or other 
conditions, the PREVAIL study represents a preventive strategy to reduce future CVD events and/or 
metabolic disease. Therefore, we feel that the examination of the project objectives in higher risk populations 
(e.g. diabetes, secondary prevention CVD, etc.) would be better addressed in a separate study with outcomes 
measures specific to those conditions. We decided to include postmenopausal women in the present 
application since the current weight maintenance guidelines for physical activity do not exclude them or have 
different exercise recommendations based on menopausal status [1]. Additionally, previous physical activity 
studies evaluating weight maintenance have included postmenopausal women [5, 53-55]. 
Table 1. Major Inclusion Criteria for Study Participation 
Age/sex 
Men and women 18-65 years of age, Postmenopausal females permitted 
BMI/Physical activity 
25-39.9 kg/m2 at enrollment, current sedentary status  
Informed Consent  
The capability and willingness to provide written informed consent  
Exclusion Criteria 
Significant CVD 
or disorders 
Including but not limited to serious arrhythmias, cardiomyopathy, congestive heart failure, stroke or 
transient ischemic attacks, peripheral vascular disease, acute, chronic or recurrent thrombophlebitis 
or myocardial infarction/stroke, postmenopausal women 
Diabetes  
Previous diagnosis or taking medication for type 1 or 2 diabetes, fasting glucose >125 mg/dL 
Blood pressure 
Systolic blood pressure >180 and diastolic blood pressure >100 [56].   
Other medical 
conditions 
Including but not limited to chronic or recurrent respiratory, gastrointestinal, neuromuscular, 
neurological, HIV or psychiatric conditions. Hospitalization over the last 5 years or currently treatment 
for mental illness.  Conditions which are life-threatening or can be aggravated by exercise training  
Other 
exclusions 
Plans to be away from the Pitt county area more than 2 weeks for the next 3 months. Pregnant or 
plans to become pregnant. Currently engaging a diet or a weight loss program. Do not own 
smartphone for MyFitnessPal and Centrepoint Apps. Non-compliance during screening visits. 
Recruitment: Participants will be recruited in the Pitt County, NC area through newspaper advertisement, 
targeted Facebook advertisement (based on age and location), emails to East Carolina University (ECU) 
employees, web-screening from a study website, targeted direct mailers, and flyers in local physician offices. 
Potential participants will be phone screened for major aspects of the study inclusion/exclusion criteria 
(summarized in Table 1). Based on a completed exercise training study in obese adults in our laboratory, we 
had a phone screen to randomization ratio of about 1:5. Therefore, we estimate that it will require 195 phone 
screen contacts during the award to obtain a sample of 39 participants. This should be feasible, as with limited 
resources, we have screened ~250 individuals per year, which is 110% of the contacts needed for the present 
study. Individuals who remain eligible following phone screen will participate in a screening visit (SV1). The 
PREVAIL-P study coordinator will consent the participant (e.g. provide information about the study, structure of 
the study, study-related procedures, risks/benefits, etc.). Individuals interested in the study following the 

consent process will fill out a calendar where they will indicate when they can attend the OPTIFAST weight 
loss class and the required exercise sessions. Participants will also identify potential back-up times for exercise 
training. In addition, the coordinator will interview the participant to assess for major barriers for study 
completion (e.g. distance from home to the facility, available time for participation, weekly time commitments, 
acceptability for participation in both weight loss and exercise components of the study). We plan to recruit 13 
overweight adults, 13 adults with Class I obesity and 13 adults with Class II obesity. We have based these 
numbers on the 1 year period of this initial grant application and the budget provided. 
An ActiGraph accelerometer (Pensacola, FL) will be used to measure steps, moderate to vigorous 
physical activity, and sleep over the course of 7 consecutive days. Participants will also wear an ActivPAL 
accelerometer (PAL technologies, Glasgow, UK) to measure the amount of sitting time. Participants will be 
instructed to wear both devices 24 hours per day and to perform their normal activities. In addition, participants 
will log their food using My Fitness Pal App (described below) for 7 days. Those that demonstrate non-
compliance (<5 days of physical activity monitor wear or fail to monitor food) will be excluded from further 
participation.  After 7 days, the participant will return both physical activity monitors and a nurse will draw blood 
to evaluate for hepatic, renal, hematological, endocrine, and metabolic function for inclusion/exclusion 
purposes. Premenopausal women will take a urine-based pregnancy test to confirm that they are not pregnant. 
After this, the participant will be scheduled for all outcome measures (Discussed in Section 5: Assessments).  
 
OPTIFAST Weight Loss Program (Initial Weight Loss): OPTIFAST is a comprehensive medically 
supervised weight loss program that combines lifestyle education and medical monitoring with portion-
controlled, nutritionally-balanced meal replacement products (shakes, bars and soups). The major goal of the 
OPTIFAST program is to provide CWL in PREVAIL participants equal to or exceeding 7% of weight loss. While 
involved in the OPTIFAST program, participants will also perform supervised exercise training at ECU.  
Participants will receive a nutrition assessment by a registered licensed dietician/nutritionist. The active 
weight loss phase of the program consists of 10 weeks with the first 8 weeks consuming full meal replacement. 
Each OPTIFAST product provides 160 – 170 calories, 14 gm protein (whey, casein, and/or soy), 3 gm total fat, 
0 trans-fat, ~20 gm carbohydrate, 220 mg sodium, 470 mg potassium, < 1 gm lactose, and 10 – 30% of the 
RDI for vitamins and minerals. Participant nutrient goals are based on BMI. For the purposes of this study (BMI 
range: 25-39.9 kg/m2), participants will consume approximately 5 OPTIFAST products per (800-820 calories 
per day, protein 70g). Measured resting metabolic rate and the exercise level of the supervised exercise 
training (described below) will also be considered when developing caloric goals. At week 8, participants have 
the option of eliminating 2 products per day and introducing 350 calories of food from a Healthy Food 
Exchange list. During this time, caloric intake usually reaches 1300–1500 calories per day. By week 10, 
participants have been transitioned, at an individual pace, to all self-prepared food except for 1 or 2 products 
daily if desired. VIDANT Wellness Clinic has over 10 years of experience delivering this intervention and the 
dieticians in the program are certified by Nestle. The cost of the weight loss program and the OPTIFAST 
products will be provided by the grants’ resources to help recruit a generalizable sample and include 
participants from socioeconomic groups who would otherwise could not afford the program. 
Classes will be delivered in a rolling fashion (e.g. participants can enter the classes at any week and go 
through a 10-week progression), which will allow the assessment schedule to be feasible when participants 
complete the weight loss component. The class typically has about 20-25 participants (and will only contain 
research participants) and will occur once per week. At each class, participants will weigh in, fill out a 
questionnaire from Nestle (regarding the number of products consumed, fluid intake, and any physical 
changes) and receive a didactic topic relevant to weight loss. About 15 minutes before the end of the class is 
left open for participants to ask individual questions with the dieticians. Participants must reach at least 7% 
weight loss at the end of the program to progress into the exercise component of the study. Those who do not 
meet this threshold will be excluded from further study participation. Data from VIDANT Wellness Center 
indicate that the OPTIFAST program has achieved CWL (≥7.0%) in 71.4% of patients who enroll in the 
program and 81.3% of those who complete the program. In the present study, we hope to increase the number 
of participants meeting CWL by providing supervised exercise training during the initial weight loss phase of 
the study [19, 57, 58] and only enrolling participants that do not have major barriers to treatment.  
 
My Fitness Pal: During the screening and the weight loss component, participants will enter data through a 
mobile App called MyFitnessPal (MFP). The App allows subjects to track the nutritional values of their diets, by 
either scanning in the barcode or searching an extensive database for their chosen food and/or drink. It 
incorporates elements of social cognitive theory, including self-monitoring, goal setting, and feedback. Total 
daily intake can be viewed in the form of caloric, nutrient or macronutrient values as graphs and pie charts, 
with warnings when preset calorie or nutrient limits are being approached. Caloric goals will be entered into 

MFP by research staff and all participants will receive training on how to utilize the app. Research staff will also 
check to assure participants are entering data into MFP at exercise training sessions. In addition, the research 
staff will enter and track compliance to entering MFP data (days entered/days required), caloric intake, and 
macronutrient composition (% carbohydrates, fat and protein). MFP data will be used to assist participants in 
tracking dietary intake. Energy intake study outcomes will be based on food frequency questionnaire.  
 
Exercise training during weight loss component: Participants will come 
to ECU 2-3 times per week for supervised aerobic training during the weight 
loss component. Exercise facilitates a greater magnitude of initial weight 
loss when combined with caloric restriction [19] and should therefore 
increase the likelihood of obtaining CWL after the weight loss component. 
The initial exercise level will be 300 MET minutes per week and increased 
by 50 MET minutes per week until the participant reaches the full amount of 
exercise during the initial weight loss component of 550 MET minutes per 
week (general public health guidelines [59]) (Table 2). Similar exercise 
volumes have been used during the initial weight loss phase [5, 60].  See 
“Exercise training procedure” for further details on exercise sessions.  
 
Rationale for the selection of CWL of ≥7%: The range for CWL is 
generally considered to be 5-10% [1] and 7% was criteria for weight loss in the Diabetes Prevention Program 
[61]. Therefore, we believe that our selection of 7% is a good balance between a magnitude of weight loss that 
confers a clinical benefit, but not so small that after minimal weight regain a participant would no longer be 
classified as having CWL (e.g. a participant with an initial weight loss of 5% and regain to 4.7%).  
Tracking of weight loss during initial weight loss phase: During the weight loss component, percent weight 
loss, magnitude of weight loss, OPTIFAST product data, estimated intake from MFP data, and weight loss 
class/exercise attendance rates will be entered into a RedCap database. These data will be monitored weekly 
at study meetings using a SAS script that will query the main RedCap database and automatically generate the 
percent weight loss and other fidelity data of all active participants.  
Randomization after attainment of CWL: Participants who achieve 7% weight loss will be randomized to 
exercise levels consistent with the minimum physical activity recommendations (PA-REC) or weight 
maintenance recommendations (WM-REC) for 18 additional weeks. The randomization list will be generated 
by the study biostatistician. This list will be maintained with a ECU staff member not associated with the study 
and with no participants contact. PREVAIL-P staff and the PI will not have access to the randomization list.  
 
Rationale for the selected exercise amounts during exercise component: The rationale for the PA-REC 
group is this is the recommended amount of exercise by AHA and ACSM to promote improved cardiovascular 
health [59, 62]. Based on previous data, this should support improvements in cardiometabolic risk factors, but 
be less optimal for weight maintenance. For the WM-REC group, we decided to target an exercise volume 
(MET min.) consistent with 250 minutes per week, which is consistent the WM guidelines (200-300 minutes per 
week) [1]. We believe this is feasible in a supervised format of 4 to 5 times per week. To inform this decision, 
we reviewed data from two aerobic training studies performed in our laboratory. Based on expected 
speed/grade of treadmill exercise at week 12 (similar to week 12 of the present proposal), we estimated that 
the average participant would exercise at a speed of 2.6 mph and 3.0% grade. Based on the proposed 
exercise level of the WM-REC group, this participant would exercise about 60 minutes 4 times per week or 50 
minutes 5 times per week. We estimated that our least fit participants would exercise at 2.4 mph and 2.0%, 
which would amount to 56 minutes 5 times per week (see derivation below). 
 
Since the weight maintenance recommendations (200-300 min/wk. at moderate intensity) is based 
solely [1] on moderate intensity physical activity, we had to translate this for a program composed of aerobic 
exercise training, which can be performed at moderate and vigorous intensities. Therefore, we decided to 
prescribe the exercise levels in the proposed study using MET min. The derivation of the exercise 
requirements in each study group are summarized in Table 3. Based on our laboratory data in obese adults, 
we estimated that the average VO2 max of participants in PREVAIL would be 23.7 ml.kg.min. We further 
estimated that 50% of VO2 max (deemed moderate intensity) [63, 64] would correspond to a VO2 during 
exercise of 11.5 ml.kg.min or 3.3 MET min. Based on this, it would require 494 MET min. per week at moderate 
exercise intensity to correspond with the current minimum physical activity recommendations of 150 min/week 
of moderate intensity exercise. Similarly, we estimated that moderate exercise at 825 MET min. per week 
would correspond to approximately 250 min. per week of moderate intensity exercise for the WM-REC group. 
Next, we needed to factor in the expected adherence rates for each group. Based on our laboratory’s data in 
obese adults, we expect at least 92% adherence to MET min. goals in the PA-REC group. Due to the 
Exercise amount 
Week 1 
300 MET min. 
Week 2 
350 MET min. 
Week 3 
400 MET min 
Week 4 
450 MET min. 
Week 5 
500 MET min. 
Week 6-10 
550 MET min.  
Table 2. Exercise progression 
in the weight loss component 

additional exercise requirements of the WM-REC group, we expect at least 85% adherence to MET min. goals. 
Therefore, we set the exercise level of the PA-REC group at 550 MET min. per week and the WM-REC group 
at 970 MET min. per week. (Table 3).   
Study 
Group 
Physical Activity Guideline 
Equivalent 
MET min. 
Expected 
adherence 
Exercise 
levels  
Expected time 
commitment 
PA-REC 
150 min/wk. mod. intensity  
494 
92% 
550 MET min. 
36 min., 3 sess. per wk. 
WM-REC 
200-300 min/wk. mod. intensity 
825 
85% 
970 MET min. 
40 min., 5 sess. per wk. 
Table 3. Summary of exercise amounts in weight maintenance phase of PREVAIL for a participant with a VO2 max of 23 ml.kg.min 
Exercise training: Participants will be required to attend supervised exercise training sessions during the 
weight loss component (10 weeks) and following OPTIFAST treatment (additional 18 weeks) at ECU. We have 
two different exercise training centers located at the FITT building (located centrally in Greenville) and at the 
(East Carolina Heart Institute, East Greenville area). Both centers are primarily used for research participants 
and we regularly train adults with obesity and CVD risk factors. Study staff will supervise training sessions at 
both sites. The weekly MET min. requirements will be divided into 3-5 sessions per week depending on group 
requirements/participant preferences. After the weight loss component, all participants in Study 1 should be 
accustomed to exercise at 550 MET min. (since there was supervised exercise training during the weight loss 
component). Therefore, participants in the PA-REC group will exercise immediately at the required levels. The 
WM-REC group, will start exercise at 600 MET min. and increase 75 MET min. per week until they reach the 
required exercise levels of 970 MET min. Every week, staff will weigh participants using a calibrated scale. 
Following a 5-minute warm-up, participants will exercise at the heart rate range associated with 50%-75% of 
VO2 max (determined from the baseline exercise test). Heart rate will be monitored and collected continuously 
(every second) during exercise sessions with Zephyr Bioharness 3 HR monitors (Medtronic Annapolis, MD). 
Following each session, heart rate data will be downloaded and mean heart rate will be averaged for database 
entry. Rating of perceived exertion will be collected every 5 minutes of the exercise session. Training data (e.g. 
mean heart rate, total energy expenditure, rating of perceived exertion, MET min. exercised and total exercise 
time) will be entered into the study database after each session. 
To enhance the accuracy of the calculation of exercise-related energy expenditure, we will perform 
monthly submaximal exercise tests to directly measure the energy expenditure rate during steady state 
exercise at the same intensity as the training sessions. A correction factor will be obtained (actual energy 
expenditure/predicted energy expenditure) to account for individual variability in prediction equations for energy 
expenditure. Indirect calorimetry has been used in previous NIH trials evaluating the effects of exercise training 
on weight to improve the accuracy of energy expenditure from aerobic exercise training [65-67]. The PI is 
currently using this methodology in an ongoing NIH funded trial (HI-PACE study, PI: Swift). 
In the event that a participant cannot make an exercise session (e.g. travel, time commitments, 
unexpected life events etc.), we will provide them a Fitbit charge accelerometer to exercise on their own to 
objectively document their exercise. Participants will be instructed to take a walk and use a Fitbit Charge 3 
GPS function (associated with their smart phone) to log their mean heart rate, time walked and distance. Study 
staff will use this information to estimate the caloric value of this walk using the ACSM walking equation [68]. 
Although this is not as accurate as supervised exercise in our facility, we felt this is a better alternative to no 
exercise training. We felt this back-up mechanism of exercise was important to maintain as high an energy 
expenditure difference between the PA-REC and the WM-REC groups as possible and offer flexibility to 
participants, which is important for both the primary outcomes of the study and overall study retention.    
Exercise training data quality: Exercise adherence will be quantified in the amount of MET min. exercised 
divided by the amount required. Exercise compliance will be defined as the amount of sessions attended 
divided by the amount of sessions required. We will actively monitor exercise adherence/compliance and other 
indicators of intervention fidelity (e.g. target heart rate compliance, wear rate accelerometers, participant 
morale, progression rate of speed/grade) on a weekly basis in study meetings. Our database will be designed 
to compute intervention fidelity measures in real time using a SAS script that queries the RedCap database 
and produces customized intervention fidelity reports. Proactive monitoring of intervention fidelity measures 
has helped us to obtain excellent training adherence in the past (>90%) by allowing our research team to 
quickly respond to participants demonstrating major risk factors for low adherence or protocol non-compliance. 
 
Nutrition management after weight loss component: By the end of the weight loss component, the 
participants will be transitioned to all self-prepared food. Participants will be placed on a weight maintenance 
diet based on the resting metabolic rate (assessed by indirect calorimetry) obtained after the weight loss 
component (with the physical activity level of the study group taken into account). In both study groups, 
participants will be provided a caloric range to support maintenance and encouraged to follow the 2010-2015 

Dietary Guidelines for Americans [69], which includes consuming less than 10 percent of calories per day from 
added sugars, 10 percent of calories per day from saturated fats, and less than 2,300 mg per day of sodium. 
Dr. Matarese (Ph.D., R.D.) will use resting metabolic rate (RMR) data to prescribe caloric ranges.   
 
Behavioral management of participants in exercise groups: Several strategies will be utilized to promote 
high exercise adherence. Extensive pre-screening will be performed inclusive of run-in visits (evaluation of 
available time to exercise, exercise calendars, assessment of time commitments) to screen-out participants 
with very high drop-out risk. We will provide monthly progress reports to maintain intrinsic motivation for 
exercise (e.g. attendance rate, changes in speeds/grade, miles walked, etc.). Other strategies for reducing 
attrition/ poor adherence will be modeled after the retention recommendations provided by the NIH [70].  
We will monitor adherence weekly in study meetings. Participants with adherence levels <75% or that 
display major warning signs for low adherence (e.g. frequent rescheduling, missed sessions, low morale) will 
meet with the research coordinator to problem-solve the causes of poor adherence and to create a plan to 
improve adherence. If adherence levels remain less <75% or issues related to the low adherence remain 
unresolved, the participant will be referred for motivational enhancement therapy (i.e. motivational interviewing) 
to increase intrinsic motivation for exercise which will be performed at the same time of the training sessions to 
not increase participant burden. Motivational enhancement therapy [71] will be provided by a doctoral student 
in clinical health psychology trained in the administration of motivational Interviewing. Numerous reviews and 
meta-analyses support that motivational interviewing is effective at promoting and maintaining health behavior 
change, including exercise [72]. Should adherence remain low or deteriorate further, booster motivational 
interviewing sessions will be employed. If the previous methods are not effective or drop-out risk is determined 
to be especially high, the participant will be referred to the lead behaviorist of the trial (Robert Carels, Ph.D.). 
 
Tracking of changes in diet and non-exercise physical activity: Non-exercise physical activity will be 
tracked using a GT9X Link accelerometer (ActiGraph, Pensacola, FL). Devices will be blinded using the 
ActiGraph software, so participants will not be able to see their data. During exercise training sessions, 
accelerometers will be removed from participants to avoid mixing exercise and non-exercise physical 
activity data. Recharging of the device (14-day battery life) will be performed during the exercise session by 
study staff while participants are exercising. Study staff will use ActiGraph’s database program (Centrepoint, 
Pensacola, FL) to monitor and download non-exercise physical activity data (e.g. steps, moderate to vigorous 
physical activity, sleep, wear/non-wear rates). The Centrepoint program will update in our database using an 
app in the participants’ mobile device or can be uploaded manually at our facility. Our research team has used 
accelerometers to monitor non-exercise physical activity in a similar manner with excellent device wear 
compliance in a completed AHA funded study (~96%) and an on-going NIH study (~97%). Block food 
frequency questionnaires [73] will be used to measure energy intake at each study time point.  
 4. Study 2: The major goal of Study 2 is to provide preliminary data to demonstrate that the weight 
maintenance physical activity recommendations will have a greater impact on weight and cardiometabolic risk 
factors compared to the minimum physical activity recommendations. Given that the R56 mechanism is a 1-
year grant, it is not possible to test the full weight loss intervention proposed in the R01 (12 weeks of 
OPTIFAST treatment and subsequent randomization to exercise for 36 weeks [48 total weeks]), especially 
when considering anticipated study start-up and recruitment time. Therefore, our plan is to recruit 30 
overweight or obese individuals who are currently in, near completion or who have very recently completed the 
VIDANT OPTIFAST program (<2 weeks with maintenance of at least 7% weight loss) and exercise participants 
for 36 weeks. VIDANT Health documents each participant’s BMI and weight at the beginning of the program. 
Therefore, we can determine the percent weight loss retrospectively and whether the participant was 
Table 4. Schedule of assessments Study 1 
Baseline Weight loss 
component 
(1-10 weeks) 
Attainment  
of CWL 
(Week 10) 
Mid-Exercise 
Component 
(Week 18)   
Follow-up 
 
(Week 26) 
Weight, Anthropometrics 
X 
X 
X 
X 
DEXA, RMR 
X 
X 
X 
Blood pressure  
X 
X 
X 
Lipids, lipoprotein sub-fraction, CRP, fitness 
X 
X 
X 
OGTT, arterial stiffness, central blood pressure 
X 
 
X 
 
X 
ActivPAL (sitting behavior and total EE) 
X 
 
X 
X 
X 
ActiGraph accelerometers (Non-exercise PA)  
X 
X 
X 
X 
X 
Energy intake (FFQ) 
X 
X 
X 
X 
SF-36 
X 
 
X 
 
X 

overweight or obese at the start of the program. Our consent forms will be written to inform participants that if 
enrolled, we will contact VIDANT Health about their baseline weight/BMI. The recruitment criteria for the Study 
2 study is very similar to Study 1 and is summarized in Table 5. Major inclusion criteria include previously 
overweight or obese (BMI: 25-40 kg/m2) at enrollment in the VIDANT OPTIFAST program and documented 7% 
weight loss at the conclusion of the program. Major exclusions include diagnosis of T2D, cardiovascular 
disease, previous history of cardiovascular events, thyroid conditions, or contraindications to exercise training.  
Table 5. Major Inclusion Criteria for Study Participation in Study 2 
Age/sex 
Men and women 18-65 years of age, Postmenopausal females permitted 
BMI/Physical activity 
25-39.9 kg/m2 at OPTIFAST enrollment and documented 7% weight loss  
Informed Consent  
The capability and willingness to provide written informed consent  
Exclusion Criteria 
Significant CVD 
or disorders 
Including but not limited to serious arrhythmias, cardiomyopathy, congestive heart failure, stroke or 
transient ischemic attacks, peripheral vascular disease, acute, chronic or recurrent thrombophlebitis 
or myocardial infarction/stroke, postmenopausal women 
Diabetes  
Previous diagnosis or taking medication for type 1 or 2 diabetes, fasting glucose >125 mg/dL 
Blood pressure 
Systolic blood pressure >180 and diastolic blood pressure >100 [56].   
Other medical 
conditions 
Including but not limited to chronic or recurrent respiratory, gastrointestinal, neuromuscular, 
neurological, HIV or psychiatric conditions. Hospitalization over the last 5 years or currently treatment 
for mental illness.  Conditions which are life-threatening or can be aggravated by exercise training  
Other 
exclusions 
Plans to be away from the Pitt county area more than 2 weeks for the next 3 months. Pregnant or 
plans to become pregnant. Do not own smartphone for MyFitnessPal and Centrepoint Apps. Non-
compliance during screening visits. 
 
Recruitment: Upon receiving IRB approval, PREVAIL-P staff will do brief presentations at VIDANT health’s 
OPTIFAST program to classes to present information to potential participants. Interested participants will 
contact our research staff and will set-up a screening visit to be consented for Study 2 by the research 
coordinator. Potential participants will be notified that if they complete the OPTIFAST program with CWL 
(≥7%).  A nurse will perform a blood draw to evaluate for hepatic, renal, hematological, endocrine, and 
metabolic function for inclusion/exclusion purposes. Outcome measures for Study 2 will not be assessed until 
the participant completes the OPTIFAST program with CWL. Participants will also be offered the use of our 
ECU exercise facility to enhance the likelihood of CWL with a goal of 550 MET min. per week or greater and 
offered use of Fitbits to help them increase physical activity levels. Within 2 weeks of completion of the 
OPTIFAST program and obtainment of CWL, 
all baseline outcome measures (Table 4) will 
be assessed and participants will be 
randomized to the PA-REC or the WM-REC 
groups (Figure 3). 
Exercise training intervention: Participants in 
Study 2 will start exercise training at 300 MET 
min. per week and increase by 75 MET min. 
until they reach the maximum MET min. goal of 
their group assignment. Participant in the PA-
REC group will reach the required exercise volume (550 MET min.) by week 5 and the WM-REC group will 
reach the required exercise volume of 970 MET min. by week 9. Both groups will continue at this exercise 
volume till the end of the intervention. The energy gap (difference in total MET min. between both exercise 
groups) is 12,340 MET min. In other words, it would take the PA-REC group 22 additional weeks of exercise 
Table 5. Schedule of assessments in the Study 2 
Baseline 
(After CWL) 
Mid-intervention 
(Week 18)   
Follow-up 
(Week 36)  
Weight 
X 
X 
X 
DEXA, Anthropometrics 
X 
X 
X 
Blood pressure  
X 
X 
Lipids, lipoprotein sub-fraction, CRP, fitness 
X 
X 
OGTT, arterial stiffness, central blood pressure 
X 
 
X 
RMR, ActivPAL (sitting behavior and total EE) 
X 
X 
X 
ActiGraph accelerometers (Non-exercise PA)  
X 
X 
X 
Energy intake (FFQ) 
X 
X 
X 
SF-36 
X 
X 
Figure 3. Study 2 Flow diagram 

training at 550 MET min. per week to equate the exercise volume of the WM-REC group. All exercise training 
sessions methodology will be the same as described for Study 1. In brief, participants will perform exercise 
training 3-5 times per week dependent on group assignment. The aerobic exercise intensity will be the heart 
rate associated with 50%-75% VO2 max and heart rate will be evaluated continuously during the exercise 
sessions. RPE will be taken every 5 minutes. Participants will wear accelerometers during the entire 
intervention to assess non-exercise physical activity (devices will be removed during exercise sessions). 
Exercise compliance and adherence will be monitored in all research participants.  
Behavioral management/nutritional management: Behavioral and nutritional management of participants 
will be the same procedures as described in Study 1.  
5. Assessments: Methodology for primary and secondary measurements are shown below. Train schedules 
for both the Study 1 and Study 2 are shown in Table 4 and Table 5 (shown above), respectively.   
 
Primary Outcome- Change in Weight:  The primary outcome measure of the PREVAIL study is change in 
weight (as a continuous variable) after obtaining clinically significant weight loss to follow-up of the intervention. 
Weight will be evaluated using a calibrated scale to the nearest tenth of kg with the participant in a fasted state 
(12 hours), wearing only a hospital gown and after the participant has voided. 
Secondary measures: Secondary measures will be collected at all 3 assessment points with the exception of 
accelerometry/doubly labeled water (obtained prior to each assessment period). We specifically chose 
cardiometabolic risk factors which have been shown in the literature to improve with weight loss, exercise 
training (independent of weight loss), or a combination of both. The rationale for this is that it is possible 
that even in the presence of weight regain after CWL, aerobic training may attenuate the deleterious effect on 
cardiometabolic risk factors. Thus, we will evaluate the effect of the proposed intervention on traditional (lipid 
concentrations, brachial systolic/diastolic blood pressure), non-traditional (fitness, lipoprotein particles size and 
subclass, c-reactive protein, pulse wave velocity, augmentation index, central blood pressure) CVD risk factors 
and a type 2 diabetes risk factor (insulin sensitivity). In addition, we will obtain total energy expenditure, 
sedentary behavior, non-exercise physical activity, energy intake and macro/micro nutrient information to 
inform energy balance apart from exercise training. We will also obtain quality of life (QOL) via the SF-36 to 
have a behavioral measure of the impact of the intervention. The PI has published on weight loss and insulin 
sensitivity [74, 75], fat loss [75] and c-reactive protein [76] and lipoprotein particle size [75]. Assessments will 
be performed approximately 48 hours following the last exercise session.  
Categorical weight maintenance: We will compare the percentage of individuals in each group that are able 
to maintain at least 3% of the initial weight loss [1] 
Oral glucose tolerance test: An intravenous (IV) line will be placed in an antecubital vein for blood draw 
purposes and will remain there throughout the testing. A resting fasting blood sample will be drawn after which, 
participants will drink a sugar solution consisting of 75 grams of glucose. Additional blood samples will be 
drawn 0, 30, 60, 90, and 120 minutes after drinking the glucose beverage. Samples will be archived at -80°C 
until sample analysis. Insulin AUC and glucose AUC will be determined following sample analysis. Insulin 
sensitivity will be estimated using the Matsuda index [77]. At baseline, OGTT measurements will occur prior to 
exercise testing to avoid confounding these measurements with acute exercise. At follow-up, OGTT will occur 
48 hours following the last exercise session, and precede exercise testing.  
Maximal Exercise Test: A modified Balke treadmill (Trackmaster 425, Carefusion, Newton Kansas) protocol 
will be used to determine cardiorespiratory fitness, and the appropriate heart rate range for aerobic exercise 
training. Participants will walk at an initial speed of 2.0 mph with 0% grade for the first 2 minutes after which the 
treadmill speed will increase to 3.0 mph for the next 2 minutes. Treadmill grade will be increased by 2.5% 
every 2 minutes until volitional exhaustion. Respiratory gases (VO2, CO2) and ventilation will be measured 
continuously using a True Max 2400 Metabolic Measurement Cart (Parvomedics, Salt Lake City, Utah). A 
physician will be present to supervise exercise testing at all study assessment points. The electrocardiogram 
during the baseline exercise test will be cleared by a physician prior to randomization to study groups. 
Pulse wave velocity and Aortic blood pressure parameters: Participants will refrain from large meals and 
caffeine for at least 2 hours and alcohol, vigorous exercise and vasoactive medication for at least 12 hours. 
Testing will occur in a quiet temperature controlled room [78]. Carotid to femoral pulse wave velocity (PWV) 
and aortic blood pressure parameters will be measured using a SphygmoCor XCEL (Itasca, IL).  PWV will be 
obtained in the supine position after a 15-minute rest. PWV parameters will be obtained in duplicate in concert 
with current guidelines [78]. Aortic blood pressure parameters (brachial blood pressure, aortic blood pressure, 
augmentation index) will be obtained in the seated position after a 5-minute rest.  
Dietary data: FFQ questionnaire data will be assessed using the NutritionQuest (Berkley Inc.) data-on-
demand system, which will facilitate immediate scoring and estimation of caloric and macronutrient intake.  

Other secondary outcomes: Body composition will be measured using dual energy x-ray absorptiometry 
(DEXA). Waist circumference will be evaluated with a gulick tape measure at the natural waist. Quality of life 
will be measured by the short form health survey (SF-36) [79]. Blood glucose, insulin, lipids, c-reactive protein, 
and lipoprotein particle size/class will be measured through standard analytical techniques. Resting metabolic 
rate (RMR) will be assessed via indirect calorimetry using a ventilated hood in the fasted state and in a supine 
position. RMR data will be collected for 30 minutes after 15 minutes of rest. An ActivPAL accelerometer will be 
worn for 7 days to assess time spent sitting/standing and total energy expenditure. 
 
6. Data management: Study data will be stored in a Red Cap © database [80]. The database will be designed 
to develop recruitment reports (e.g. total contacts, reasons for exclusion during screening, screen to 
randomization ratio for recruiting projections), weight loss program data (% weight loss, class attendance, etc.) 
and exercise training data (e.g. exercise adherence, heart rate compliance) and outcome data. Recruiting, 
weight loss program and exercise training data reports will be reviewed to monitor the intervention fidelity. 
 
7. Statistical Design: Primary analysis will first check for baseline differences between the groups to help 
determine possible covariates that need to be taken into account.  Intent to treat analysis will be conducted first 
followed by those that had high adherence to the exercise group (>75%). The analysis for the primary aim 
(weight change) will be a mixed effect linear model with change in weight as the outcome. In brief summary, 
this model will use the baseline, weight loss midpoint, and the follow-up weights all awhile accounting for the 
baseline covariates as well as the weekly weight changes.  Results will be reported as least square means with 
t-test used to test for differences both between and within groups. Changes in cardiovascular risk factors will 
be evaluated in a similar manner as weight, with mixed effect linear models.  Particular focus will be given to 
both the baseline changes and the changes after the clinically significant weight loss. Both set of covariates will 
be used with variable selection methodology to determine if there is a set of covariates that can predict the 
outcome of the weight maintenance phase. To evaluate categorical differences between groups in regards 
weight maintenance, we will use a mixed effect logistic model to model the probability of achieving weight 
maintenance, with results presented as adjusted odds ratios. 
 
8. Preliminary data and experience of the study team: Collectively, 
the study team has significant experience implementing weight loss and 
exercise training interventions. VIDANT Wellness Center has 
documented success in achieving 7% weight loss (71% of enrolled 
participants, 81% of participant completing the program). Dr. Matarese 
will oversee the delivery of the nutritional intervention. She has 
experience in nutritional interventions as she was the Co-PI of a recently 
completed multi-center study sponsored by Abbott (N= 652). In addition, 
she uses OPTIFAST treatment within her clinical practice and both Drs. 
Matarese and Pories have a completed multicenter randomized trial 
evaluating OPTIFAST weight loss treatment [81]. Dr. Robert Carels is the 
psychology departments’ director of clinical training. He has used 
motivational interviewing for weight control in obese populations [82] and 
has performed both weight loss and maintenance interventions [82-89]. 
His role on the present study will be to provide behavioral support to 
participants demonstrating risk of drop-out or low adherence. Dr. Walter 
Pories will be the medical investigator and has served this role on studies 
using an OPTIFAST diet and bariatric surgery. Dr. Corby Martin 
(expertise in energy balance) will serve as a consultant on the grant.  
The PI and Dr. Houmard have a history implementing supervised 
exercise studies (Table 5). The PI has 44 publications in exercise training 
and CVD/T2DM risk factors. He is a former NIDDK T-32 postdoctoral fellow in Preventive Medicine 
(Pennington Biomedical, Mentor: Timothy Church, M.D.), which focused specifically on large scale exercise 
training trials. In terms of independent extramural funding, Dr. Swift has obtained NIH and AHA funding as the 
PI of exercise trials (AHA scientist development award, NIH R03). In addition, the Dr. Swift is a Co-I on the NIH 
common fund MoTrPAC study. The PI has published 10 articles evaluating the effect exercise training level on 
CVD risk factors [75, 90-97]. In specific reference to weight loss and exercise, the PI has published 2 review 
articles on the effect of physical activity on weight loss and weight maintenance [95, 98]. The PI has published 
2 papers showing that weight loss amplifies health benefits even in participants performing aerobic training. 
Figure 4A shows the change in HOMA-IR in overweight/obese women participating in 6 months of aerobic 
training. Those that achieved greater than 5% weight loss (and even 3% weight loss) had greater reductions in 
Figure 4. Changes in insulin 
sensitivity with weight loss A) Swift 
et. al. Obesity 2016. B) Swift et. al. 
Plos One 2018 

HOMA-IR compared to those that did not lose weight (<3%). Figure 4B shows that insulin sensitivity 
(measured via an intravenous glucose tolerance test) in overweight/obese adults participating in 8 months of 
aerobic training. While insulin sensitivity was improved in participants that did not lose weight (<3% weight 
loss), a greater improvement in insulin sensitivity was observed in participants who achieved at least 3% 
weight loss. In the same paper, the PI showed that modest weight loss is associated with improvements in 
triglycerides, non-HDL cholesterol, LDL particle size, total LDL particles and HDL particle size compared to 
those that do not lose weight [75]. These results informed incorporating these variables in this proposal.   
Dr.  Houmard has been the ECU site PI on multi-center NIH funded exercise trials (e.g. STRRIDE I, 
STRRIDE AT/RT) including being an exercise training site PI on the MoTrPAC study (see Table 6). The PI will 
assume complete responsibility for leading this trial. However, Dr. Houmard will provide senior mentorship for 
the PI given that he is an early stage investigator. Dr. Houmard is the PI’s faculty mentor. Mentorship of the PI 
is included within Dr. Houmard’s job responsibilities of his faculty appointment at ECU. Thus, no additional 
effort is needed from this grant for mentorship activities.   
Investigator 
Study  
N 
Population 
Role 
Adherence 
Swift, D 
HI-PACE (NIDDK) 
36† 
Obese African Americans  
PI 
98.6% 
Swift, D. 
I-CAN (AHA) 
45  
Obese adults  
PI 
92.1% 
Swift, D. 
Walkmore (AHA) 
120 
Postmenopausal women  
NIH T-32 Postdoc 
NSE,NPI 
Swift, D. 
Fit for Life (NIH) 
57 
Elderly adults >70 yrs. 
NIH T-32 Postdoc 
NPI 
Swift, D. 
E-Mechanic (NIH) 
198 
Adults 18-65 yrs. 
NIH T-32 Postdoc 
NPI 
Houmard, J.  POWER (NIH) 
48* 
Adults after gastric bypass 
ECU site PI 
NSE 
Houmard, J. 
STRRIDE I (NIH) 
67* 
Overweight adults  
ECU site PI 
90.6% 
Houmard, J 
STRRIDE II (NIH) 
75* 
Overweight adults  
ECU site PI 
86.9% 
Table 6. Previous experience in NIH and AHA funded exercise and physical activity trials *We have reported the n of participants that have 
been recruited through the ECU site of the study; †ongoing study, NSE: not supervise exercise, NPI: Swift not the PI 
9. Study Timeline: The timeline of PREVAIL-P is shown in Table 7. Study start-up will occur during month 1 
and 2 of the grant. The start-up will include the creation of a manual of procedures (MOP), development of 
standard operating procedures (SOPs), training of all research staff on procedures/visits, mock run-throughs of 
clinical visits and exercise training methodology. In addition, we will develop a custom-made RedCap database 
to include all study outcome measurements, tracking of recruitment and creation database reports for 
monitoring variables suggestive of the overall intervention fidelity. We plan to begin recruitment of both Study 1 
and Study 2 in month 1-4 of the 
grant award. We plan to 
complete the intervention from 
month 3-11 of the grant award. 
Lastly, we plan to complete 
data collection by the end of the 
11th month of the study after 
which the research team will 
then verify study data, perform 
data cleaning/statistical 
analyses and write/submit the 
primary outcomes paper. 
10. Rigor and Reproducibility: Most blood analyses will utilize LabCorp Inc., which has a CLIA certification 
for accuracy in methods of analysis. Gas calibration will occur prior to submaximal or maximal indirect 
calorimetry. Current guidelines will be followed for arterial stiffness measures procedures and the machine will 
be calibrated annually. Weight will be measured on a calibrated scale in the fasted state. Glucose and insulin 
from OGTT samples will be measured in duplicate. During study start-up, all procedures and methods will be 
documented in the MOP and investigators will approve the MOP before the initiation of data collection.  
11. Potential Pitfalls: 1) Low adherence and sufficient separation between exercise groups: Obtaining high 
adherence and adequate differences in the exercise levels are critical to the success of the study. The 
investigative team has demonstrated the ability to implement exercise training with excellent adherence to the 
6-month time point (>90%) based on our current AHA/NIH funded exercise trials. We have established several 
safeguards to reduce the enrollment of participants with high drop-out risk by evaluating for indicators of low 
adherence in our screening procedures (semi-structured barriers interview) and we have an intervention plan 
lead by behavioral personnel to intervene on participants exhibiting warning signs for low compliance 
(overseen by Robert Carels, Ph.D.). The research team monitors adherence in all participants weekly to 
Table 7. PREVAIL-P Timeline 
Study Month 
 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
MOP/SOP development, training 
 
 
 
 
 
 
 
 
 
 
 
 
Recruitment of Study 1 
 
 
 
 
 
 
 
 
 
 
 
 
Recruitment of Study 2 
 
 
 
 
 
 
 
 
 
 
 
 
Intervention 
 
 
 
 
 
 
 
 
 
 
 
 
Follow-up testing 
 
 
 
 
 
 
 
 
 
 
 
 
Data management/cleaning 
 
 
 
 
 
 
 
 
 
 
 
 
Data analysis 
 
 
 
 
 
 
 
 
 
 
 
 
Paper writing and submission  
 
 
 
 
 
 
 
 
 
 
 
 

quickly intervene on participants who are not meeting exercise goals. NIH R01s using similar procedures have 
obtained high exercise adherence (>90%) and retention (>85%) [33, 99, 100].  2) The PI is an early stage 
investigator:  The PI has a strong history of publication in exercise amount and CVD risk factors, and has 
obtained significant research funding as the PI for a junior investigator including a career development grant 
from the AHA and a R03 from NIDDK (both exercise training interventions). While the PI will assume complete 
and total responsibility for leading the trial, Joseph Houmard (co-investigator) has substantial experience in 
NIH sponsored exercise trials, and will provide senior mentorship to the PI for any other study-related issues 
(along with the other co-investigators). Drs. Pories and Matarese are Co-PIs of a published 52-week 
OPTIFAST diet study [81]. Dr. Martin will visit ECU during study start-up and the intervention period to assist 
with MOP development and early protocol issues (see letters of support). 3) Failure to recruit: We are confident 
that we can recruit the proposed study as described. To assure that we are able to meet our recruitment goals, 
we have budgeted ($7,000 dollars) for recruitment material and for a 20 hour a week staff member who will 
perform recruiting calls after hours (5PM) and during weekends during the recruitment phase of the study.  
    
12. Alternative approaches: We considered using the exercise volume corresponding to 300 minutes per 
week for the exercise prescription in the WM-REC group (which is the maximum value recommended by the 
weight maintenance guidelines), but this may be burdensome to participants with very low fitness, who would 
have to come more than 5 times per week to exercise or have very long exercise sessions (>60 mins. per 
session). Therefore, we felt that the selection of targeting the exercise volume associated with 250 minutes per 
week struck a good balance between an amount of exercise that would promote weight maintenance, but was 
also feasible in a supervised setting. In addition, we felt that this was the best choice to support high retention 
and adherence to the exercise levels in the WM-REC group. 
 
13. Limitations: An important limitation is the PREVAIL-P study will occur under laboratory conditions in which 
staff will ensure high compliance to the amount of exercise. Thus, the study is not designed to determine 
methods of motivating participants to achieve these exercise levels in a real-life setting, which represents an 
important research question. However, given the lack of data of prospective trials in this area and that these 
recommendations have been disseminated, we feel that it is necessary to first determine the effects of 
different exercise levels on weight maintenance and cardiometabolic risk factors as this may better inform how 
to properly design future effectiveness studies. Another limitation is that there are many nutritional and physical 
activity interventions to induce CWL. Thus, the proposed study cannot address whether an interaction effect 
exists between the weight loss regimen utilized and magnitude of weight maintenance. Due to 1-year of 
funding in the present mechanism, we cannot evaluate the impact of the intervention on long-term weight loss 
outcomes. However, we plan to study the cohort of participants within PREVAIL-P and the subsequent R01 
(future grants applications) to begin to address long term weight loss.  
 
14. Conclusion: The PREVAIL-P study will provide valuable data to inform the design of an R01 on the impact 
of exercise level on weight loss and cardiometabolic risk factors after CWL. We are confident that both projects 
will demonstrate that are approach is robust and will justify further funding of this clinical trial. Study 1 will 
demonstrate the ability of the study team to implement the weight loss intervention and demonstrate 
adherence to exercise training after CWL. Study 2 will allow the study team to adequately power primary and 
secondary outcomes for weight maintenance trial for the R01 application. A fully powered R01 on the impact of 
exercise training level on weight, body composition and cardiometabolic risk factors directly addresses 
limitations in this research area identified by a recent ACSM position stand [1] and an NIH sponsored working 
group [101] on weight maintenance by randomizing individuals to groups following a clinically significant weight 
loss, prospectively measuring exercise training amount (supervised exercise), non-exercise physical activity 
(objective physical activity monitors) throughout the entire intervention. The results of the PREVAIL study will 
have high clinical implications given the high rates of regain following weight loss treatment and further inform 
future physical activity guidelines on weight loss maintenance. If funded, subsequent renewals of the R01 
application could aim at following these cohorts to examine long-term weight loss, incorporating apps to 
increase physical activity levels in weight maintenance or determine the effect of other exercise programs after 
CWL (e.g. intensity, modality, etc.). We believe the results of this R56 proposal and subsequent R01 proposal 
have the potential to be published in a top tier medical or obesity journal and will be of great interest to 
physicians, clinicians and public health professionals treating overweight and obese adults.

 
 
 
 
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Wing, R.R. and S. Phelan, Long-term weight loss maintenance. The American Journal of Clinical 
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Soleymani, T., S. Daniel, and W.T. Garvey, Weight maintenance: challenges, tools and strategies for 
primary care physicians. Obesity Reviews, 2016. 17(1): p. 81-93. 
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Kroeger, C.M., K.K. Hoddy, and K.A. Varady, Impact of Weight Regain on Metabolic Disease Risk: A 
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Statistical Analysis Plan 
Title:  Prevail R-56 
 
 
Principal Investigators: Swift  
 
 
 
Version: 1.0(09-6-18) 
 
Final  
 
 
 
 

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TABLE OF CONTENTS 
TABLE OF CONTENTS ................................................................................................................................ 2 
1 
INTRODUCTION ................................................................................................................................... 4 
1.1 
Preface ................................................................................................................... 4 
1.2 
Purpose of the analyses .......................................................................................... 4 
1.3 
Study aims and endpoints ....................................................................................... 4 
1.3.1 
Aim 1 ....................................................................................................................................... 4 
1.3.2 
Aim 2 ....................................................................................................................................... 4 
1.3.3 
Aim 3 ....................................................................................................................................... 4 
1.4 
Exploratory aims ..................................................................................................... 5 
1.4.1 
Initial weekly weight loss ......................................................................................................... 5 
1.4.2 
Mediator and moderator analyses ........................................................................................... 5 
1.4.3 
Association between weight loss, weight maintenance, and energy expenditure ..................... 5 
2 
STUDY METHODS ............................................................................................................................... 5 
2.1 
Sample .................................................................................................................... 5 
2.2 
Randomization ........................................................................................................ 5 
2.3 
Sample size and study power .................................................................................. 5 
2.3.1 
Aim 1 ....................................................................................................................................... 6 
2.3.2 
Aim 2 ....................................................................................................................................... 6 
3 
STATISTICAL PRINCIPALS ................................................................... Error! Bookmark not defined. 
3.1 
Distributional assumptions ...................................................................................... 7 
3.2 
Outcome measures ................................................................................................. 7 
3.2.1 
Primary .................................................................................................................................... 7 
3.2.2 
Secondary ............................................................................................................................... 7 
3.3 
Covariance structures ............................................................................................. 7 
3.4 
Covariates ............................................................................................................... 7 
3.5 
Mediation and moderator analyses .......................................................................... 8 
3.6 
Subgroups ............................................................................................................... 8 
3.7 
Missing data ............................................................................................................ 8 
3.8 
General reporting conventions ................................................................................ 8 
3.9 
Statistical summary conventions ............................................................................. 8 
3.10 Interim analyses ...................................................................................................... 9 
4 
ANALYSIS ............................................................................................................................................. 9 
4.1 
Analysis Populations ............................................................................................... 9 
4.2 
Demographic and Baseline Variables ...................................................................... 9 
4.3 
Analyses of the primary aims .................................................................................. 9 
4.3.1 
Aim 1 ....................................................................................................................................... 9 
4.3.2 
Aim 2 ................................................................................................................................. …..9 

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4.3.3 
Aim 3 ....................................................................................................................................... 9 
4.4 
Analyses of the Exploratory Aims .......................................................................... 10 
4.4.1 
Initial weekly weight loss ....................................................................................................... 10 
4.4.2 
Mediator and moderator analyses ......................................................................................... 10 
4.4.3 
Outcome transformation ........................................................................................................ 10 
5 
REFERENCES .................................................................................................................................... 11 
 
 
 

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1 INTRODUCTION 
1.1 Preface 
Achieving clinically significant weight loss (CWL) (5-10%) has been shown to improve important 
cardiometabolic risk factors in obese adults (e.g. insulin sensitivity, dyslipidemia, systemic inflammation, 
blood pressure). However, only 20% of individuals achieve weight loss maintenance and even mild weight 
regain (2-6%) is associated with regression of risk factors toward pre-weight loss levels. Obtaining high 
amounts of physical activity (PA) are critical for successful weight loss maintenance. The Prescribed 
Exercise to Reduce Recidivism After Weight Loss pilot (PREVAIL-P) study will evaluate the effect of 
aerobic exercise training amount on weight maintenance following CWL in obese (BMI: 25-40 kg/m2) men 
and women ages 18-65 years old.  In study 1, volunteers will complete a 10-week OPTIFAST weight loss 
program. Individuals who achieve a weight loss of at least 7% from baseline weight will be subsequently 
randomized to levels of aerobic training consistent with half of physical activity recommendations (PA-REC) 
or weight maintenance recommendations (WM-REC) group for 16 additional weeks. Exercise sessions will 
be directly supervised by study staff to confirm exercise-related caloric expenditure. Non-exercise physical 
activity will be assessed objectively through accelerometry during the entire intervention in all 
randomization groups. For study 2, participants who are currently in or have nearly completed the VIDANT 
OPTIFAST program and achieve at least 7% weight loss will be randomized to either the PA-REC group or 
the WM-REC group for the next 36 weeks.  
 
The primary outcome of PREVAIL-P for both study 1 and study 2 is the change in weight from the 
completion of the OPTIFAST program (achievement of clinically significant weight loss) to follow-up. 
Secondary measures include the proportion of participants achieving weight maintenance, changes in 
clinically relevant cardiometabolic risk factors (insulin sensitivity, arterial stiffness, fitness, fat mass, lipids, 
lipoprotein particle size and c-reactive protein), and energy intake between study groups.  
1.2 Purpose of the analyses 
The analysis will test if participants whether a physical program after clinically significant weight loss 
consistent with weight maintenance recommendations (WM-REC group) will have better health outcomes 
compared to participants in the physical activity recommendations (PA-REC) group.  
1.3 Study aims and endpoints 
The overarching goal is to test the effectiveness recommendations effect weight maintenance and 
cardiovascular risk factors. 
1.3.1 Aim 1 
To demonstrate the efficacy of the weight loss program in producing CWL and retention/adherence of the 
exercise intervention. Overweight and obese adults (N=39) will participate in an OPTIFAST weight loss 
program and supervised aerobic exercise training (~550 MET min. per week.) for 10 weeks. Participants 
who obtain CWL will be subsequently randomized to 16 weeks of aerobic training consistent with the 
minimum physical activity recommendations (~550 MET min per week.) or weight maintenance guidelines 
(~970 MET min per week). We will evaluate the percentage of participants that obtain at least 7% weight 
loss following OPTIFAST treatment, retention rates in the weight loss program, adherence to exercise 
levels, and changes in weight and cardiometabolic risk factors in response to the intervention.  
 
1.3.2 Aim 2 
To test the hypothesis that exercise levels consistent with weight maintenance recommendations leads 
to greater weight maintenance after CWL compared to the minimum physical activity recommendation 
levels. Overweight and obese adults (N=30) enrolled in VIDANT health’s OPTIFAST program and have 
achieved at least 7% weight loss will be randomized to 36 weeks of aerobic exercise training consistent 
with the minimum public health guidelines for physical activity (~550 MET min. per week.) or weight 
maintenance levels (~970 MET min per week). We will evaluate the effect of the intervention on weight 
(primary) as well as main secondary measures (e.g. body fat, visceral fat, lipids, lipoprotein particles 
size/class, insulin sensitivity, blood pressure, arterial stiffness, systemic inflammation, fitness, and quality of 
life). The aforementioned cardiometabolic risk factors were selected because they can be improved 
specifically by weight loss and thus may respond differently to weight maintenance or regain.  

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1.4 Exploratory aims  
We have planned the proposed research program such that our Primary Aims, described above, are the 
foundation of a rigorously designed study with mechanistic hypotheses. Such a study design requires focus 
and derivation of hypotheses that are strongly supported by preliminary data and adequate study power. 
Through this process we have identified many promising hypotheses that did not meet our rigorous criteria 
for being a Primary Outcome. These outcomes are of great significance but have less supporting evidence 
and we have classified them as secondary and exploratory outcomes. These additional outcomes are 
presented below and are referenced in the methods and herein. They are not, however, developed to the 
same extent as the Primary Aims. 
1.4.1 Initial weekly weight loss 
To examine the baseline factors of the participant achieving the clinically significant weight loss of 7% in the 
first 12 weeks of the study (Study 1 only)  
1.4.2 Mediator and moderator analyses 
To determine if there are any baseline or after initial weight loss have a  mediating/moderating the effect on 
weight maintenance and cardiovascular risk factors. Association between weight loss, weight maintenance, 
and energy expenditure   
 
To determine if initial weight loss and weight maintenance in the second phase is related to energy 
expenditure. 
2 STUDY METHODS 
The PREVAIL-P study will be divided into Study 1 and Study 2.  Study 1  will use a parallel arm design with 
two intervention arms. Each patient will be followed for 10 weeks during the initial weight loss and an 
additional 16 weeks of weight maintenance.  Measurements on the primary outcomes will be conducted at 
weeks 0, 10, and 26.  
In Study 2, participants already in or very recently completed the OPTIFAST program in VIDANT and achieve 
a 7% weight loss will be randomized exercise groups (36 weeks afterwards). Study 2 will use a parallel arm 
design with two intervention arms.  Primary outcomes in study 2 will be performed at 0,18, and 36 weeks.  
2.1 Sample  
The inclusion criteria for a participant include the following:  
• 
The ages of 18-65,  
• 
BMI between 25.0-39.9 kg/m2, 
• 
Current sedentary status (<2 days per week of exercise) 
• 
Physically capable of exercise 
2.2 Randomization 
After initial weight loss (in both Study 1 and Study 2), participants who achieve 7% weight loss in the 
OPTIFAST program will be randomized to exercise levels consistent with physical activity 
recommendations (PA-REC) or weight maintenance recommendations (WM-REC) . The randomization for 
the proposed study will be generated by the study biostatistician, who will also be responsible for 
randomizing participants to study groups. No other research staff (including the PI) will have access to the 
study randomization. The randomization will be stratified by BMI Class (overweight, Class I and Class II) 
and gender to assure equal distribution to study groups. 
2.3 Sample size and study power 
The goal of the PREVAIL-P study is to provide feasibility of the weight loss intervention/subsequent 
exercise (Study 1) and power primary and secondary variables for a definitive trial (Study 2). Thus, this R56 

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will be used to inform the design of a subsequent.  The originally sample size calculation called for 225 
subjects to have 80% power.  Based on Cocks, we will need at least 9% of the original sample to obtain 
proper estimates.  This initial percent is doubled to 18% to account for the increased complexity as 
compared to the instance described by Cocks. 
2.3.1  Aim 1 
 
To demonstrate the efficacy of the weight loss program in producing CWL and retention/adherence of the 
exercise intervention. Overweight and obese adults (N=39) will participate in an OPTIFAST weight loss 
program and supervised aerobic exercise training (~550 MET min. per week.) for 10 weeks. Participants 
who obtain CWL will be subsequently randomized to 16 weeks of aerobic training consistent with the 
minimum physical activity recommendations (~550 MET min per week.) or weight maintenance guidelines 
(~970 MET min per week). We will evaluate the percentage of participants that obtain at least 7% weight 
loss following OPTIFAST treatment, retention rates in the weight loss program, adherence to exercise 
levels, and changes in weight and cardiometabolic risk factors in response to the intervention.  
 
The goal of this aim is to demonstrate feasibility of the research team to successfully deliver the weight loss 
program and subsequent exercise training. We estimate that we can obtain at least 76.0% of the 
participants to achieve clinically significant weight loss. Thus, we expect at least 30 of the 39 to reach the 
exercise component of the trial. We felt that at least 15 participants per group would be a good sample to 
demonstrate the adherence of the subsequent exercise training program. We expect to complete 90% of 
the participants who have obtained significant weight loss.  
 
2.3.2 We will evaluate several metrics of feasibility from Study 1 including the percent of 
participants meeting the weight loss goal of 7%, attendance of the weight loss classes, 
attendance at exercise classes, adherence to exercise goals during (MET minutes exercised 
vs. MET minutes required).  
2.3.3 Aim 2 
To test the hypothesis that exercise levels consistent with weight maintenance recommendations leads to 
greater weight maintenance after CWL compared to the minimum physical activity recommendation levels. 
Overweight and obese adults (N=30) enrolled in VIDANT health’s OPTIFAST program and have achieved 
at least 7% weight loss will be randomized to 36 weeks of aerobic exercise training consistent with the 
minimum public health guidelines for physical activity (~550 MET min. per week.) or weight maintenance 
levels (~970 MET min per week). We will evaluate the effect of the intervention on weight (primary) as well 
as main secondary measures (e.g. body fat, visceral fat, lipids, lipoprotein particles size/class, insulin 
sensitivity, blood pressure, arterial stiffness, systemic inflammation, fitness, and quality of life). 
2.3.4 The major goal of Study 2 is to power main and secondary measures for a definitive trial 
on physical activity level after clinically significant weight loss.  Our goal is to complete at least 
10 participants per group (90% retention) for power analyses for a definitive trial.  
 
3 STATISTICAL PRINCIPALS 
Analyses will use SAS Version 9.4 (SAS Institute, Cary NC). The primary methodology will be linear mixed 
effect models.  Repeated effects will account for the patient’s correlations over time. Further details about the 
covariance structures is given below. Results will be given in the form of both the raw beta coefficient when 
the predictor is continuous and as least square means when the predictor is categorical. Overall F-tests will 
be done for sets of beta coefficients that correspond to the same grouping variable (i.e. gender or race 
interactions). When the overall F-test is significant, pairwise T-test will be investigated, with alpha adjusted 
for the number of comparisons. Whenever possible visualization of these results will be given by scatter plots 
with the overall beta coefficients used as slope estimators overlaid on the plots. 

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3.1 Distributional assumptions  
Preliminary statistical testing will be performed to investigate homoscedasticity and normality of model 
residuals. The Shapiro–Wilk test will be used to test for normality of residuals for outcomes modeled with a 
linear mixed model. For non-normal data, a log or square root transformation will be applied and retested. If 
these transformed data again indicate non-normality, non-parametric tests will be used. The Mann-Whitney 
U test will be the primary non-parametric test. This test uses the sum of the ranks to determine if the samples 
are from the same distribution. Due to the large number of possible ties in the data, the Mann-Whitney U test 
may not be the best test. In such situations, the Kolmogorov–Smirnov test will be used. This test is based on 
the largest difference in the empirical distribution function of the two groups. As such, it is not as sensitive to 
ties in the data.  
3.2 Outcome measures 
3.2.1 Primary 
The primary outcome measure of the PREVAIL-P study is change in weight after obtaining clinically 
significant weight loss to follow-up of the intervention. Weight will be evaluated using a calibrated scale to the 
nearest tenth of kg with the participant in a fasted state (12 hours), wearing only a hospital gown and after 
the participant has voided. 
3.2.2 Secondary 
For Study 1, secondary measures will be collected at all 3 assessment points with the exception of 
accelerometetry (obtained prior to each assessment period). We specifically chose cardiometabolic risk 
factors which have been shown in the literature to improve with weight loss, exercise training (independent 
of weight loss), or a combination of both. The rationale for this is that it is possible that even in the presence 
of weight recidivism, that adherent exercise training may attenuate the deleterious effect of weight regain on 
cardiometabolic risk factors. Thus, we will evaluate the effect of the proposed intervention on traditional (lipid 
concentrations, brachial systolic/diastolic blood pressure), non-traditional (fitness, lipoprotein particles size, 
c-reactive protein, pulse wave velocity, augmentation index, central blood pressure) CVD risk factors as well 
as a type 2 diabetes risk factor (insulin sensitivity), total energy expenditure, energy intake and quality of life. 
The PI has published on significant weight loss and insulin sensitivity [6], weight/fat loss and c-reactive protein 
[7] and lipoprotein particle size. Quality of life (QOL) will be measured via the SF-36 questionnaire. QOL 
improves with aerobic training in a dose response manner [8] and also improves with weight loss [9-11], and 
thus may vary between groups in the present proposal.  
For Study 2, secondary measures will be assessed at baseline and follow-up (with the exception of 
weight and body composition which will also be assessed at mid-intervention). Covariance structures 
The variance-covariance structure of the repeated effects will be dependent on the variability among all 
participants. A preliminary test will be conducted to assess significance of the homogeneity of variances [10-
12] for between treatment arm differences. The within-patient variability will be modeled with an unstructured 
covariance matrix. Correlation patterns will be assessed with Akaike’s Information Criterion (AIC) to make 
final selections. 
3.3 Covariates 
Covariates in the generalized linear mixed model will include, but not limited to the follow: 
• 
time point 
• 
time point*treatment interaction  
• 
age 
• 
gender 
• 
initial weight  
• 
race/ethnicity 
• 
socioeconomic status 
Other potential covariates may include using the baseline measures of several of the primary and secondary 
outcomes.   
Variable selection in select linear models will be determined though model fit statistics such as AIC. 

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3.4 Mediation and moderator analyses 
Mediations will investigate how the covariates affect the relationship between weight gain and the 
intervention [13]. Mediation analyses will be applied using both structural mean models and principal 
stratification [14]. Preacher and Hayes bootstrapping methods, as well as the Sobel test, will be used to test 
potential mediations of the outcomes.  The advantage of using the Preacher and Hayes bootstrapping 
methods over just the Sobel test include greater power and distributional free assumptions.  Mediation will 
be done using the CALIS procedure in SAS along with the MIXED procedure and IML for the bootstrapping 
methods.   
We will use the Baron and Kenny method and bootstrapping methods for moderator analysis. A statistically 
significant interaction will define age as a moderator. This interaction will only be removed from the model 
when not statistically significant.  
While any of the covariates could be potential mediator or moderators, we only investigate a subset of 
these variables.  Weight change will be the primary variables of interest.   
3.5 Subgroups 
Heterogeneity of variance effects for genders for each of the treatments will be analyzed first as potential 
subgroups. While these sample sizes are not powered to detect differences between each subgroup, these 
results will be invaluable by providing directionality for future hypotheses.  
3.6 Missing data 
Data may be missing because participants drop out or fail to complete an instrument or assessment. Three 
patterns of missing data will be considered: missing completely at random (MCAR), missing at random 
(MAR), and missing not at random (MNAR). Data are MCAR if events that lead to all missing values are 
independent of both the observed and missing values. Data are MAR if the events depend on the observed 
values but are independent of the missing values. If the missing data mechanism depends on specific 
reasons related to the missing data themselves, then the values are MNAR.  
Sensitivity analyses will be performed to investigate whether different analyses under different assumptions 
provide robust inferences. Four analyses will be used: 1) a mixed effects linear model for repeated measures 
that makes use of all data irrespective of missing data; 2) completers analysis with participants who have 
complete data on the primary outcomes; 3) mixed effects linear time trend model with random coefficients; 
and 4) multiple imputation analysis using the MCMC methods. The robustness of the inferential findings to 
the analytic methods will be assessed by comparing differences in analytical findings across the four 
analyses. 
3.7 General reporting conventions 
Descriptive and summary statistics will be generated for outcomes and covariates of interest. For all 
outcomes, all continuous variables will be summarized using n (non-missing sample size), mean, standard 
deviation (SD), standard errors (SE), correlations (R), minimum (Min), maximum (Max), and coefficient of 
variation (CV). The frequency and percentages (based on the non-missing sample size) of observed levels 
will be reported for all categorical measures, unless otherwise specified.  
 
All tables, figures and data listings will be presented in portrait orientation, unless landscape orientation 
suggests that the information is easier to view. All titles will be centered on a page. For tables, sample sizes 
for each treatment group will be presented as totals in the column header (N=xx), where appropriate. 
Sample sizes shown with summary statistics are the number (n) of patients with non-missing values. 
Summaries for categorical variables will include only categories that patients had a response in. 
Percentages corresponding to null categories (cells) will be suppressed.  
3.8 Statistical summary conventions 
The mean and SD will be reported to one decimal place greater than the original data. Minimum and 
maximum will use the same number of decimal places as the original data. All percentages will be rounded 
and reported to a single decimal place (xx.x%). If percentages are reported as integers, percentages greater 
than 0% but <1% will be reported as <1%, whereas percentages greater than 99% but <100% will be reported 
as >99%. A percentage of 100% will be reported as 100%. No value of 0% will be reported. Any computation 

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of percent that results in 0% is to be reported as a blank. Summaries that include p-values will report the p-
value to three decimal places with a leading zero (0.001). P-values <0.001 will be reported as “<0.001”.  
3.9 Interim analyses 
No interim analyses are planned.  
4 ANALYSIS 
All primary outcomes are analyzed as using change scores.  The linear mixed effect models will use the 
outcome as the response for the primary outcomes.  Full details about each set of models is given in 
Section 3. 
4.1 Analysis Populations 
The primary statistical analyses will rely on intent-to-treat (ITT) methodology, with all patients’ data included 
who have a measurement at baseline and follow-up. A per protocol analysis will also be conducted as a 
secondary analysis. 
4.2 Demographic and Baseline Variables 
These data will include (but are not limited to) height, weight, BMI, body composition, and blood pressure 
lipids, fitness, sitting behavior, total energy expenditure, accelerometers results, food frequency 
questionnaire, and SF-36. F-tests followed up by pairwise T-tests and chi-squared test will be used to 
determine if any differences occur between groups. Baseline variables for all psychological, behavioral, and 
physical measures will also be investigated to ensure a random and balance sample. 
4.3 Analyses of the primary aims 
4.3.1 Aim 1 
4.3.2 To demonstrate the efficacy of the weight loss program in producing CWL and 
retention/adherence of the exercise intervention. Aim 2 
Although the primary purpose of the present study is to evaluate feasibility/efficacy of the weight loss 
intervention/exercise (Study 1) and powering weight maintenance variables (Study 2). We will still evaluate 
the impact of the intervention outcome variables. For both Study 1 and Study 2, weight will be the primary 
outcomes measure and the other cardiometabolc variables will be considered secondary outcomes. In 
addition, the percent of participants maintain weight (categorical analysis) will also be considered a 
secondary endpoint. 
Primary outcome: To determine the magnitude of weight maintenance (as a continuous variable) in 
response to different levels of exercise training after CWL   
 
Initial results will be based on a linear mixed effect model with the change scores as the outcome. The 
model will use random effects to account for the correlation in a participant over time.  Results from this 
model will be reported as least square means, with p-values based on t-tests.  Two different sets of models 
will be used.  The first set of models will contain only treatment, while the second is will also contain the 
covariates based on the model selection process. Pairwise post-hoc comparisons of the category variables 
will be corrected for multiple comparisons will be made when necessary.  
Secondary outcomes:  
 
To determine the percentage of individuals (as a categorical variable) who are able to maintain weight loss 
maintenance in response to different levels of exercise training after CWL 
 
Logistic mixed effect model with the probability of achieving weight maintenance, with results presented as 
adjusted odds ratios. The model will use random effects to account for the weight differences at baseline.  
Results from this model will be reported as odd ratios, with p-values based on Chi-squared statistics.  Two 
different sets of models will be used. The first set of models will contain only treatment, while the second is 

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will also contain the covariates based on the model selection process. Pairwise post-hoc comparisons of 
the category variables will be corrected for multiple comparisons will be made when necessary.To 
determine the change in clinically relevant cardiovascular risk factors in response to different levels of 
exercise training after CWL 
 
Models similar to the ones used in Aim 1 will be used here as well. Outcomes for this aim include both 
traditional (lipid concentrations, brachial systolic/diastolic blood pressure), non-traditional (fitness, 
lipoprotein particles size, c-reactive protein, pulse wave velocity, augmentation index, central blood 
pressure) CVD risk factors as well as a type 2 diabetes risk factor (insulin sensitivity), total energy 
expenditure, energy intake and quality of life. 
4.4 Analyses of the Exploratory Aims 
4.4.1 Initial weekly weight loss 
Mixed effect models will be used to model the weekly weight changes in the first 10 weeks. Baseline 
covariates will be used to determine which set of covariates best predicts the weight at week 10.  
4.4.2 Mediator and moderator analyses 
Baseline covariates will be tested as both mediating/moderating effects on weight maintenance and 
cardiovascular risk factors. See section 3.4 for full details of these tests.   
4.4.3 Outcome transformation 
Almost all primary outcomes will be based on change from baseline.  However, this model makes 
assumptions about the data that may not be valid when the final data is reviewed.  The primary assumption 
of concern is that change from baseline is not dependent on the starting value since all arms should have 
approximately equal due to randomization. This assumption will be investigated using a two-sample t-test 
on the baseline values. Whenever this assumption is violated, two other models will be investigated.  The 
first alternative model will use the baseline time in addition to the follow-up times. This model allows for 
testing of change in group means over time as opposed to the primary model that tests individual change 
over time. The second alternative model will use only the follow-up times and with initial time as a 
covariate. This model assumes that baseline group means are equal and the follow-up values are adjusted 
for this overall baseline value.  Comparisons and contrasts will be made between all three model for similar 
tests when possible. 
 
 
 

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3. 
Church, T.S., et al., Effects of Different Doses of Physical Activity on Cardiorespiratory Fitness 
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Swift, D.L., et al., Effect of Exercise Training Modality on C-Reactive Protein in Type 2 Diabetes. 
Medicine and Science in Sports and Exercise, 2012. 44(6): p. 1028-1034  
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