Exercise as a Buffer Against Stress-induced Overeating
Phase: NA
Conditions: Obesity
Sponsor: The Miriam Hospital

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Exercise as a buffer against stress induced overeating 
ClinicalTrials.gov #: NCT02936076 
 
Study Protocol 
10.11.17 

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Study overview: Subjects will be recruited to participate in this study via advertisements in local newspapers, 
internet postings, and community newsletters. Interested individuals will be screened via the telephone to 
determine initial eligibility (see full eligibility criteria below). If deemed eligible via the phone screen, participants 
will be invited to an orientation session where they will learn additional details about the study, sign an 
informed consent document, and complete baseline assessment measures. Participants will then be 
randomized to a 12-week exercise training program or a delayed exercise condition (see below for more 
details). Assessments will take place at baseline and 12 weeks. Participants will not be compensated for the 
baseline assessment visit. At 12 weeks, they will be compensated $25 for completing study questionnaires, a 
food choice computer task, and measures of weight, fitness and body composition. Further, at baseline and 12 
weeks, participants will be asked to respond to prompts via their smartphone 5x/day over a 14-day period while 
also wearing an armband that objectively measures physical activity. At week 12, participants will receive 
$0.50 for each EMA prompt responded to within 45 minutes and a completer’s bonus of $30 if they have >80% 
compliance and wore the armband for at least 9 days for ≥10 hours/day.  
 
Eligibility criteria: To be eligible for the study, participants must be female, aged 18-60, have a BMI of 25 to 40 
kg/m2, own a smartphone, and be willing to receive and respond to text message prompts for 14 days at 
baseline and 12 weeks. Exclusionary criteria include: shift workers, those who do not endorse stress-eating, 
recent weight loss or current enrollment in a weight loss program, women who are pregnant, those with any 
medical condition that would limit participation in physical activity, diabetes, or an inability to walk without an 
assisted device or inability to meet exercise recommendations. Participants with a previous history of heart 
disease or hypertension will be required to provide physician consent prior to participating in this study. 
Further, individuals with <80% compliance to the EMA monitoring at baseline or those with poor compliance to 
wearing the armband will not be eligible to participate. 
 
Treatment conditions: 
 
1. Exercise condition: Participants randomized to the exercise condition will participate in a 12-week 
exercise training program and asked not to alter their dietary habits during this time. The exercise 
intervention will consist of both supervised and unsupervised exercise sessions. The exercise 
prescription will start out at 100 minutes/week of moderate-intensity exercise and progress to 200 
minutes/week. During the first 4 weeks, they will engage in 2 supervised exercise visits/week in which 
their heart rate will be monitored by a member of the research staff to ensure that exercise is within the 
prescribed intensity range. During Weeks 5-12, participants will engage in 1 supervised visit/week. At 
these supervised exercise visits, heart rate, ratings of perceived exertion and feeling state will be 
assessed periodically. The remaining exercise will be performed on their own. To help facilitate 
exercise adherence, participants will be required to have a gym membership and will be reimbursed up 
to $40/month depending upon the cost of their local gym. Further, ‘exercise’ participants will be given 
an armband to wear over the 12-week period during all exercise sessions in order to verify compliance 
to the exercise protocol. Since the goal of this study is to determine how exercise training influences 
eating behaviors and other psychological parameters, participants will be incentivized to exercise. They 
will receive $10 in cash for each week that they meet the exercise goal and a $50 bonus (in the form of 
a gift card) if they averaged >180 min/week over the 12-week period as verified via the armband. Thus, 
they can receive a total of $170 for performing the prescribed exercise.  
 
2. Delayed exercise condition: Participants randomized to the delayed exercise condition will be asked 
not to change their exercise or eating habits over the 12-week period and will complete the same 
assessment measures as the exercise condition. However, following the completion of the 12-week 
assessment period, participants will be given two options: 1) receive a one-on-one session with an 
exercise physiologist at our center and receive a written exercise program, or 2) complete the identical 
exercise protocol as the ‘exercise’ condition. If participants choose option 2, they will receive the exact 
program outlined above and also complete additional assessments at 24 weeks (similar to those 
described for week 12). 

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Assessment measures: 
 
In-person visit: Height will be assessed at baseline and weight and body composition will be assessed at 
baseline and 12 weeks. Body composition will be assessed via bioelectrical impedance analysis (RJL Systems 
Quantum II impedance machine). Participants will be asked to fast for 4 hours, refrain from alcohol for at least 
12 hours, and to refrain from strenuous exercise or sauna for 8 hours prior to these measures. As part of these 
assessment visits, participants will also be given a series of questionnaires (see measures below), be 
equipped with an armband (used to measure physical activity), and will be instructed on how to respond to the 
EMA prompts over the 14-day EMA period.  
 
EMA protocol: Participants will be asked to carry their smartphone for 14 days at baseline and 14 days at the 
end of the intervention. They will report on their stress, mood, hunger, physical activity, overeating episodes, 
and dietary temptations/lapses as they occur in their natural environment. All entries will be made in response 
to 5 semi-random prompts delivered throughout the day (between 8:00am and 10:00pm) via text message. 
Upon receiving the text message, participants will have 45 minutes to click on the link provided and this will 
direct them to an online questionnaire. Each set of questions will take 3-5 minutes to complete and individuals 
<80% compliant at baseline will be ineligible to participate in the study.  
 
Sensewear Armband:  Participants will wear a Sensewear armband (Body Media, Pittsburgh, PA) for 14 
consecutive days (to coincide with the EMA monitoring period) at baseline and 12 weeks. This device is worn 
on the upper arm and provides valid and reliable estimates of exercise intensity and energy expenditure via a 
unique combination of sensors (accelerometer, galvanic skin response, heat flux, and skin temperature). 
Structured exercise bouts (≥10 minutes of activity ≥3 metabolic equivalents) will be identified and total daily 
energy expenditure will be computed to examine whether these variables influence stress levels or overeating-
episodes. Participants in the exercise condition will also be asked to wear this armband during all exercise 
sessions as these data will be used to confirm participants self-reported physical activity over the 12-week 
intervention period. 
Fitness testing: A graded exercise test (GXT) to 75% of age-predicted maximal heart rate will be conducted 
at baseline and 12 weeks. Participants will walk on a treadmill at 3.0 mph and the incline of the treadmill will 
increase every two minutes until the subject’s HR reaches 75% of their age-predicted maximum. Time on the 
treadmill and the estimated MET value upon test completion will be used to assess changes in fitness over 
time.  
Food choice decision-making computer task: Participants will complete the food choice decision making 
task as part of their 12-week assessment visit. Using the methods employed in Hare and colleagues (2009) 
each participant will provide health and taste ratings on 150 different food items using a 5-pt scale1. Foods 
include a range of unhealthy (e.g., chips or candy bars) and healthier (e.g., apples or broccoli) items. From 
these ratings a food rated as neutral in both taste and health will be selected for each individual participant as 
a reference item for the decision-making portion of the task. Participants then decide for each of the other food 
items if they would rather eat that target food or the reference item using a 4-pt scale (strong yes, yes, no, 
strong no) to note the strength of each choice. Special emphasis will be placed on these decisions by informing 
participants that one trial will be randomly selected and they must eat the food that they chose at the end of the 
experiment. In this way participants are encouraged to make honest, true-to-life judgments as any one trial 
could be the one selected. Ratings and decision data will allow us to determine the degree to which 
participants value health and taste in their decision-making (i.e., the extent to which ratings of food health and 
tastiness independently correspond to choices). 
 
Questionnaires to be administered at baseline and 12 weeks: 
 
• 
Three-Factor Eating Questionnaire (TFEQ)  

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• 
Eating Self Efficacy Scale (ESES)  
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Perceived Stress Scale (PSS)  
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Weight Bias Internalization Scale (WBIS) 
• 
Distress Tolerance Scale (DTS) 
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Pain Catastrophizing Scale (PCS) 
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Barratt Impulsiveness Scale (BIS)  
• 
Modified Trait Food-Cravings Questionnaire (FCQ-T)  
• 
Power of food scale (PFS) 
• 
Bull’s Eye II 
• 
Self-regulation Questionnaire for Exercise (SRQ-E) 
• 
Food craving Inventory (FCI) 
• 
Paffenbarger Physical Activity Questionnaire (PPAQ)