Mindfulness and Acceptance Based Behavioral Treatment for Weight Loss
Phase: NA
Conditions: Obesity, Weight Loss
Sponsor: Drexel University

Cover Page 
 
Official Title: Mindfulness and Acceptance Based Behavioral Treatment for Weight Loss 
 
NCT number: NCT04337619 
 
Document Date: 09/21/2021 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

1. Project background 
 
Obesity is associated with numerous health problems and all-cause mortality [1,2]. Gold- 
standard weight loss interventions (behavioral treatment; BT) generally produce clinically 
significant weight losses of 5–8% [3]. Certain mindfulness and acceptance-based treatments 
(MABTs) have demonstrated superior weight loss efficacy to BT [4,5]. However, outcomes 
are heterogeneous, likely because MABTs vary considerably in components included and 
emphasized (see Table 1) [4–9]. 
 
Because MABTs are delivered as packages, determining which intervention components 
drive weight loss is difficult. Mediation analyses provide preliminary support of willingness- 
and values-linked mechanisms of action [4–6], but are limited in interpretability due to 
measurement error (e.g., limited insight, recall or demand biases), assessment timing 
(i.e., measuring mediators too early or late) [10], and because they do not clarify 
which components affect which mediators [11]. Thus, current understanding of efficacious 
MABT components is limited, hindering the streamlining, cost-effectiveness and further 
improvement of MABTs. 
 
An ideal method for optimizing MABTs is the Multiphase Optimization Strategy (MOST) 
framework, a comprehensive method for optimizing and engineering multicomponent 
interventions [12] which involves identifying core components within multicomponent 
interventions and using a factorial design to test each component’s individual and interactive 
efficacy. A randomized controlled trial (RCT) can then evaluate the optimized intervention 
(containing the most efficient combination of components) [13]. The MOST framework 
identifies active treatment components, thus enabling the creation of enhanced intervention 
packages more quickly than successive RCTs. Yet, despite the promise of this approach, 
only one study has used it to optimize weight loss treatment [14]. 
 
Consistent with Phase I of MOST, we reviewed theoretical and empirical literature and 
identified three key MABT components [4–8]: 1) mindful awareness (paying attention to 
and labeling internal experiences); 2) willingness (accepting or being willing to experience 
all internal experiences, so as to engage in beneficial behaviors regardless of desires to avoid 
or reduce discomfort); and 3) values (clarifying what one finds most meaningful in life to 
guide decision-making). 
 
Consistent with Phase II of MOST, we will evaluate the independent and interactive efficacy 
of each identified component. Following a 2 × 2 × 2 factorial design, we will randomly 
assign individuals with overweight/obesity to one of eight conditions, each representing a 
permutation of the MABT components delivered alongside foundational BT content. We 
will examine outcomes at mid-treatment (6-months) post-treatment (12-months, the primary 
study endpoint), and 6-, 12-, and 24-month follow-up. The primary aim is evaluating the 
independent efficacy of the MABT components on weight loss above BT. The secondary 
aims are: 1) evaluating the independent efficacy of components on calorie intake, physical 
activity, and quality of life; 2) evaluating target engagement and 3) testing the hypothesis 
that susceptibility to internal and external food cues moderates component efficacy (i.e., 
those with greater susceptibility benefit most). The exploratory aims are quantifying any 
component interaction effects, which may be synergistic, fully additive, or partially additive. 
An ultimate aim of this work is to construct an optimized treatment that includes efficacious 
components (e.g., producing ≥2% additional weight loss—alone or in concert with another 
component—at the furthest assessment for which such clinically meaningful differences are 
observed). 

 
2. Methods 
 
Study design 
The current clinical trial will use a MOST approach, including a 2 × 2 × 2 factorial 
design. Consistent with the factorial design, we will randomize 288 participants with 
overweight/obesity to one of eight conditions, stratifying by BMI category (<30, 30–40, 
and > 40), sex, and race (White and Other). Randomization will occur at the baseline 
assessment and will be conducted by the study coordinator using a table containing 
predetermined group assignments designed to equally balance the distribution of participant 
across treatment components based on sex and race. Assessors (e.g., research staff and 
graduate students) but not interventionists, will be blinded to allocation, and allocations 
will also be evident (although not explicitly stated) to participants. The eight conditions 
represent all combinations of the following treatment components turned On or Off 
(see Table 2): Mindful Awareness (“Awareness”), Willingness (“Willingness”) and Values 
Clarity (“Values”). The base of each condition will be a 20-session, small group-based, 
gold-standard behavioral weight loss program. Thus, the eight treatment conditions will 
be: Behavioral treatment (BT) only (treatment as usual), and BT in conjunction with a 
combination of the three core MABT components: BT + Values, BT + Awareness, BT + 
Willingness, BT + Awareness + Values, BT + Awareness + Willingness, BT + Willingness 
+ Values, and BT + Awareness + Willingness + Values. MABT components will be adapted 
from prior treatments, such as Acceptance and Commitment Therapy (ACT) [15,16], 
Dialectical Behavior Therapy (DBT) [17], Relapse Prevention for addictive behaviors [18], 
Mindfulness-Based Eating Awareness Training (MB-EAT) program [6,19], as well as prior 
MABTs for weight loss [4,5,20,21]. 
 
Trial registration—The study was pre-registered on ClinicalTrials.gov (identifier: 
NCT04337619) and conducted through Drexel University. The Drexel Institutional Review 
Board approved all procedures (protocol number: 1903007097). 
 
Interventions 
Groups will last 85–130 min, depending on the number of components included (see Table 
2). The goal of session timing and structure is to allocate an equal amount of time for 
foundational BT content across conditions, and for time allotted to each MABT component 
to be consistent across conditions for which that component is included (i.e., turned On). 
Consistent with standard procedures [22], groups initially will meet weekly, then decrease in 
frequency to facilitate increasing autonomy. Group sessions will be conducted via the Zoom 
videoconference platform. Participants will submit and receive feedback on assignments 
(worksheets and food records) via Google Classroom, an online learning platform. (The 
study was initially designed to be held in-person, but COVID-19 necessitated a switch to 
remote format.) 
 
Session structure—Groups will begin with “individual consultations” in which 
participants will meet one-on-one with one of the two study interventionists in Zoom 
breakout rooms to discuss individualized weight trajectory and key issues. Individual 
consultations will each last approximately 3 min for each participant. During the time that 
participants are waiting for their individual consultation or for the group session to start 
(approximately 15 min), they will be in a virtual “waiting room” with the other participants 
to facilitate unstructured conversation and group cohesion. Afterward, group check-ins will 
be conducted, in which participants will report to the group on compliance with their 
calorie prescription, exercise prescription, daily dietary self-monitoring, and homework 

completion. The remainder of the session will be devoted to presenting skills and discussing 
strategies. Following each session, participants will be assigned worksheets to facilitate 
skills utilization (“skill builders”) and will be asked to submit food records. Participants 
will submit and receive feedback on these assignments in Google Classroom. Group leaders 
will leave comments on materials to facilitate skills utilization and increase accountability 
between sessions. 
 
Foundational behavioral treatment (BT)—This component, which will form 
the foundation of each additional component, consists of core gold-standard behavioral 
weight loss strategies adapted from the Diabetes Prevention Program (DPP) [22] and Look 
Ahead [23]. Participants will be provided with a calorie intake prescription designed to 
induce approximately 1–2 lbs. (0.45–0.91 kgs) of weight loss per week based on baseline 
body weight: <250 lbs. (113 kg), 1200–1500 cal per day; >250 lbs. (113 kg), 1500–1800 
cal per day [24]. Participants will also be provided with physical activity guidelines based 
on weekly minutes of moderate-to-vigorous physical activity, gradually increasing to 250 
min per week [25,26]. Other topics will include nutrition and physical activity education, 
prescriptions to self-monitor intake using a mobile app (MyFitnessPal), stimulus control 
techniques, setting individualized behavioral goals, problem-solving barriers to change, 
improving social support and preventing relapse. Participants will be provided with frequent 
praise and reinforcement for achieving behavioral and weight goals and will receive 
individualized feedback on weekly self-monitoring records. 
 
Awareness—This component, adapted from the MB-EAT program [19], teaches 
mindfulness techniques to promote the deliberate regulation of attention and awareness 
of the current moment, including internal experiences (e.g., one’s thoughts, emotions, 
sensations, hunger and fullness) [27,28]. Participants will be taught to monitor their internal 
experiences before, during, and after eating and exercise bouts to explore cognitive and 
affective factors contributing to these behaviors. Experiential exercises will cultivate innate 
appetitive regulatory processes in part by teaching participants to tune into their internal 
fullness, hunger, and taste satiety signals [6,19,29]. For instance, participants will be guided 
through increasingly complex mindful eating exercises (e.g., mindfully eating a raisin, 
decadent snacks, and then a multi-component meal to simulate the experience of eating at a 
buffet). An emphasis will be placed on eating for quality rather than quantity. Additionally, 
participants will be encouraged to develop a regular 15-min daily meditation practice outside 
of sessions [30] and to engage in brief “pre-meal meditations” (i.e., pausing and tuning into 
the present moment and one’s internal experiences prior to meals) [19]. Participants will be 
taught to make eating decisions with both “inner wisdom” (i.e., knowledge of one’s fullness, 
hunger, and taste satiety) and “outer wisdom” (i.e., calorie tracking and portion control 
strategies). In this way, we couple Mindful Awareness strategies with core BT strategies. 
The overarching goal in this component will be to help participants increase physical activity 
levels and adhere to calorie targets through moving from mindless/automatic patterns of 
eating and sedentary behavior to mindful/deliberate eating- and exercise-related decisions. 
 
Willingness—The component will provide participants with strategies to 
psychologically accept discomfort (e.g., urges to eat, hunger, cravings, fatigue) or a loss 
of pleasure, thereby enabling choices (e.g., eating an apple instead of a cookie) that are 
based on health goals rather than one’s internal state in a given moment [16,20]. Thus, the 
core goal of willingness will be to help participants “uncouple” internal experiences from 
chosen behaviors. To facilitate uncoupling, participants will be taught cognitive defusion 
skills to first develop the ability to “look at thoughts rather than from thoughts” and in this 
way gain distance from internal experiences [31]. For example, participants will be taught 

to label thoughts as thoughts (“I’m having the thought that”) and feelings as feelings (“I’m 
having the feeling of…”) [32]. The overall framework of the willingness component will be 
“control what you can” and “accept what you can’t.” In this way, participants will learn to 
engage core behavioral strategies (e.g., portion control, stimulus control), and to accept (i.e., 
be willing to experience) all internal experiences that arise when engaging these strategies, 
including unwanted emotions (e.g., frustration), thoughts (e.g., “this will never work”), 
and cravings. An emphasis will then be placed on the behavioral corollary of acceptance: 
that is being willing to engage in weight control behaviors even when uncomfortable or 
challenging thoughts, feelings or sensations arise. To teach willingness skills, we will 
incorporate various exercises adapted from prior treatments [15,20]. For example, in one 
exercise, participants will be asked to consider their thoughts and emotions about two food 
choices (a more hedonic food, such as a piece of chocolate, and a less hedonic food, such as 
a carrot), and to imagine the enjoyment that they would derive from the more hedonic food. 
Then, they will be asked to imagine the enjoyment that they would derive from the more 
hedonic food while choosing to eat the less hedonic food and discarding the more hedonic 
food. Of note, we will emphasize that all foods can fit within a weight loss diet when 
accounted for and will discuss willingness as a strategy that can be used to meet weight loss, 
physical activity, and calorie goals. 
 
Values—This component will be designed to facilitate clarification of values and 
connection of those values to weight control behaviors so as to generate a meaningful and 
intrinsic source of motivation with which to sustain weight control behaviors long-term. 
Consistent with prior interventions [33], this component will begin with a structured 
process for the identification of life values. For example, participants will be guided 
through exercises in which they explore and identify values in ten core life domains (e.g., 
family, community, spirituality). Consistent with principles of ACT [15,16] and intrinsic 
motivation theory [34–36], participants will be taught that they will be more motivated for 
goals that connect to freely-chosen, personal life values (e.g., living a long and healthy 
life; being a present, loving, and energetic grandmother). Participants will be taught that 
commitment to difficult behavioral goals is only likely to be maintained when one connects 
psychologically with life values meaningful enough to make such effort worthwhile. An 
emphasis will be placed on making connections between these values and weight control 
behaviors, specifically (e.g., healthy eating as a way to live out the value of being a present 
and energetic grandparent). Participants will also learn skills to keep values salient (e.g., 
through written or visual cues), and to use life values, rather than momentary desires to 
lessen discomfort, to guide decision-making. For example, participants will be taught to 
use a “values telescope” to envision how various in-the-moment decisions point towards, 
or away from, long-term values. Participants will also be taught strategies to address 
competing values (e.g., values integration and prioritization). To avoid contamination with 
the willingness condition, in this component we will emphasize using values to guide 
behaviors, but will not discuss acceptance of internal states while engaging in values- 
informed behaviors. 
 
Component integration—Each treatment condition including an MABT 
component will include a central framework (i.e., underlying model) intended to integrate 
components. Where relevant, we will reference existing protocols to inform component 
integration [4,5]. Examples of central frameworks include “the 4 M’s” (“Measure, Modify, 
Mindfulness and Motivate”) in the BT, Awareness and Values condition, and “Control What 
You Can, Engage Willingness and Use Values as a Guide” in the BT, Willingness and 
Values condition. Under “the 4 M’s” framework, participants will be encouraged to develop 
greater awareness (“inner wisdom”) surrounding hunger, satiety, urges/cravings and external 

triggers to overeat or remain sedentary, and then use inner wisdom, coupled with “external 
wisdom” (i.e., knowledge of portion control and self-monitoring strategies) to guide eating 
and physical activity decision-making. Participants will be further taught to recognize 
distinctions between “automatic” decisions (those lacking awareness) and intentional, 
mindful decisions that move them towards freely chosen weight-related values. Under the 
“Control What You Can, Engage Willingness and Use Values as a Guide” framework, 
consistent with ACT approaches [15], participants will be encouraged to practice willingness 
in the service of their values. In this case, participants will be taught to practice acceptance 
towards reductions in eating-related pleasure and discomfort associated with increasing 
physical activity and are encouraged to instead make behavior choices guided by weight- 
related values (e.g., living a long life for one’s children). Study interventionists will also be 
encouraged to integrate MABT content throughout each session to facilitate adherence to 
core strategies for weight control (e.g., self-monitoring). 
 
Contamination—Special efforts will be made to avoid contamination across 
components. For example, in conditions with Awareness On, but Willingness Off, an 
emphasis will be placed on being aware of and tuning into internal experiences, rather 
than cultivating an accepting attitude towards them. In conditions where Values is Off, 
conversations about goals will center on concrete endpoints rather than higher-order values 
that inspire those goals. Thus, when Willingness is On but Values is Off, we will emphasize 
willingness to engage in weight control behaviors in service of goals as opposed to 
underlying values. When Willingness is On but Awareness if Off, we will not emphasize 
present moment awareness, or tuning into and making distinctions between different types 
of internal experiences (e.g., biological vs. hedonic hunger, fullness and satiety). Instead, 
participants will be taught to label experiences into broad categories (i.e., thoughts or 
feelings) as a means to separate internal experiences from behavioral choices (i.e., defusion). 
 
Participants 
Adults aged 18–70 with overweight/obesity (N = 288; BMI = 25–50 kg/m2) will be recruited 
from the Philadelphia area. Participants will be recruited through a variety of streams 
including social media, radio, and flyer. All recruitment streams were approved ahead of 
time by the Institutional Review Board. Participants will first be screened briefly by phone 
to assess preliminary eligibility. Potentially eligible participants will then be invited to attend 
one of several virtual group orientation sessions (run by study investigators) where they will 
learn about the study. Interested participants will then be provided with an informed consent 
and scheduled to attend a clinical interview where full eligibility will be confirmed. 
 
Eligibility 
Individuals will be excluded if they are not able to engage in physical activity (defined as 
walking a city block without stopping); have a medical or psychiatric condition that may 
pose a risk to the participant during intervention, cause a change in weight, or limit ability to 
comply with the program; recently began or changed the dose of a medication that can cause 
significant change in weight; history of bariatric surgery; weight loss of >5% in the previous 
6 months; currently pregnant or breastfeeding; planning to become pregnant, or participate 
in another weight loss treatment in the next 3 years. BMI < 27 kg/m2 will be deemed 
ineligible at phone screen. BMI will be calculated using height measured in a medical office, 
if available from a visit in the past year; otherwise, through self-measured height (using a 
measuring tape) on the day of the eligibility screen. Similarly, phone screen BMI will be 
calculated using self-reported weight that day, or, if a participant does not have a scale, they 
will report their last measured weight. If recent (i.e., within 1-month) height or weight are 
not available, eligibility is deferred until the clinical interview. Study eligibility (in this case 

BMI < 25 kg/m2) will be reassessed at the clinical interview using weight from a wireless 
scale that we will mail to participants. Weights will automatically sync to a secure portal in 
a de-identified format accessible only to research staff. In the clinical interview, participants 
will be instructed on how to set up and calibrate their scales, and asked to follow standard 
weighing protocols (i.e., instructed to remove bulky clothes and to remove items from their 
pockets, to ensure the scale is on a hard flat surface, and step onto their scale and stand 
still). Although access to a smartphone and an internet connection will be required for all 
participants, participants who lack access will not be excluded, and will instead be loaned a 
smartphone with a mobile data connection for the duration of the study. Based on national 
rates of smartphone ownership and internet access, it is anticipated that approximately 15% 
of participants will lack access to a smartphone and/or internet connection [37]. 
 
Training and fidelity 
All groups will be led by a trained clinician with, at minimum, a master’s degree in 
psychology, nutrition, or a related field. The study will be comprised of a team of 
six clinicians. Clinicians vary in the extent to which they have training and experience 
in mindfulness- and acceptance-based treatments and behavioral treatments. Clinicians’ 
prior training will be supplemented through eight hours of training and ongoing clinical 
supervisions. All groups will also be assigned a junior co-leader (most commonly a graduate 
student in clinical psychology). Both leaders and co-leaders will receive specific training 
on the components utilized in the treatment corresponding to their group’s condition and 
have access to a manual outlining operational definitions of each component and examples 
of contamination across conditions. Study interventionists will be provided weekly clinical 
supervision for the duration of the treatment. This study will utilize the fidelity coding 
system used in a past trial that was found to have excellent inter-rater reliability [5]. To 
track fidelity, group sessions will be video-recorded and 20% of sessions will be randomly 
reviewed independently by a single co-investigator to monitor: (1) the proportion of time 
spent on each component; (2) competence and fidelity to treatment manuals; and (3) any 
contamination of treatment content across conditions. Study interventionists will receive 
feedback on their fidelity to the intervention. 
 
Assessments 
Assessments will be conducted by study staff and graduate students in the lab. These 
assessments will be completed at baseline, mid-treatment (6 months), post-treatment (12 
months) and at 6-, 12- and 24-month follow-up. (i.e., at 18, 24 and 36 months from baseline; 
Fig. 1). For one week at baseline, mid-treatment and post-treatment, participants will also 
complete ecological momentary assessment (EMA) surveys delivered at random, six times 
a day, via a smartphone application. Assessments will be conducted remotely via Zoom. 
To maximize retention and attendance of assessments, compensation will increase over 
consecutive assessments. The compensation structure is US$50 for baseline, US$100 for 
mid-treatment, US$125 for post-treatment, US$150 for 6 month follow-up, US$175 for 12 
month follow-up, and US$200 for 24 month follow-up, with deductions for noncompliance 
(e.g., US$3 for each EMA survey missed). 
 
3. Measures 
 
Primary outcomes 
Percent of initial body weight lost is the primary outcome variable. Weight will be measured 
weekly, using a wireless scale. In addition, the morning of assessments, participants will be 
asked to weigh themselves three times in immediate succession. If there is a variation greater 
than 0.2 lbs. (0.09 kg), they will be instructed to weigh a fourth time. Participants will be 

provided with detailed instructions on how to self-weigh accurately (e.g., ensuring scale is 
on a hard, flat surface, weighing upon waking but after using the bathroom, before eating or 
drinking anything, and without wearing heavy clothing or shoes). 
 
Secondary outcomes 
The secondary outcome measures are dietary intake, physical activity and quality of life. 
Measures will be taken for one week, at baseline, mid-treatment and post-treatment. 
Although dietary intake will be measured at all timepoints, data collected at mid- and post- 
treatment will be of primary of interest, as the validity of dietary self-monitoring records at 
baseline may be poor (i.e., because participants have not yet been trained in accurate and 
comprehensive tracking). Dietary intake will be recorded on the popular mobile application 
MyFitnessPal at each assessment point for 1 week (for 2 of 5 waves, we will record dietary 
intake for 3 weeks to better investigate relations between physical activity and diet). Total 
energy intake estimated using MyFitnessPal has shown a high level of concordance with 
other food composition databases [38] and also shows strong associations with energy 
intake estimated via more traditional, paper-based records, although total energy intake 
may be somewhat underestimated [39,40]. Quality of dietary intake data will be assessed 
at all timepoints through a qualitative review of individual self-monitoring records and 
by examining relationships between calorie intake and weight change within participants. 
Physical activity will be measured as minutes per week of moderate-to-vigorous physical 
activity [41] using the FitBit Charge 4, a consumer-grade wrist-worn activity tracker. A 
7-day Physical Activity Recall [42] will gather information about bouts of swimming and 
biking, and estimates of PA will be calculated with and without the self-report data. Quality 
of life will be measured using the Quality of Life Inventory [43]. 
 
Exploratory outcomes 
Target engagement—Target engagement will be assessed at each assessment 
point via behavioral and self-report measures, and with EMA items. For all study waves, 
mindful awareness will be assessed via self-report, with the Awareness subscale of The 
Philadelphia Mindfulness Scale [44]. Self-reported willingness will be assessed using the 
Food Craving Acceptance and Action Questionnaire [45] Values will be assessed using a 
structured interview [33], as well as a self-report measure, the Treatment Self-Regulation 
Questionnaire [46,47]. In the EMA protocol, participants will report on MABT strategies 
utilized over the past few hours (Mindful Awareness: “I have been fully aware of my present 
moment experience, such as my thoughts, feelings, and urges;” Willingness: “I felt I could 
make healthy eating and activity decisions regardless of my thoughts, feelings, urges;” 
Values: “I have thought about my values when making eating or activity decisions”). A 
short-term retrospective reporting period was used for EMA because we judged it relatively 
unlikely that a participant would be using an MABT strategy in the exact moment of 
receiving an EMA prompt, and because this method aligns with prior EMA studies on 
overweight/obesity and eating behavior [48–50]. EMA, rather than retrospective self-report, 
will be used to assess MABT strategies due to concerns that the latter would suffer from 
greater recall bias. Strategy use will be summed across surveys to create a composite index 
of each individual’s use of MABT strategies at each assessment point. 
 
Moderators—To evaluate the potential moderating effects of susceptibility to 
internal and external food cues, we will administer measures of food responsivity, 
disinhibited eating, emotional eating, and impulsivity. To assess food responsivity, we will 
administer a self-report measure (the Power of Food Scale [51]), as well as a computerized 
test of the association between food stimuli and “good vs. bad” categories (the Implicit 
Association Test [52]). To assess disinhibited eating, we will administer a self-report 

measure (the Eating Inventory.) Emotional eating will be measured using two self-report 
(the Emotional Eating Scale [8] and the Emotional Eating subscale of the Dutch Eating 
Behavior Questionnaire [53]). Impulsivity will be assessed using two behavioral tasks: the 
Delayed Discounting Task [54] and the Stop Signal Task [55]. 
 
Power analysis 
Although we expect that some components will demonstrate larger effects, we 
conservatively powered for a small-to-moderate (Cohen’s d = 0.30) treatment component 
main effect of ≥2% weight loss over the year-long intervention period (i.e., between 
conditions with the component turned “on” versus conditions with the component turned 
“off”). We powered for a 2% difference in our primary outcome (percent weight loss) at 
post-treatment (12 months) based upon our recent trial (which achieved >3% weight loss 
between conditions [4]), and because 2% additional weight loss is a clinically significant 
difference. We conducted the power analysis with the SAS macro %FactorialPowerPlan 
[56], assuming an alpha level of 0.05 and power of 0.80. We included covariation, based 
on variance explained in our previous trials [57]. Participants are clustered within groups 
and power calculations were performed based on participants, rather than clusters, being 
randomly assigned to each of the 8 conditions. We conservatively assumed a weight loss 
standard deviation of 10 (based on previous weight loss trials) and an intraclass correlation 
coefficient (ICC) of 0.10 based on an ICC of 0.06 in our most recent trial [4] (which used 
similar recruitment methods and clustering to 18 groups), a projected 12 participants per 
cluster. Participants will be randomly assigned individually as opposed to by intact clusters. 
Given these assumptions and accounting for 25% attrition (based upon past work [4,7–9]), a 
total of N = 288 individuals (n = 36 per cell) are needed. Of note, the SAS macro assumes 
effect rather than dummy coding, which is important for the secondary and exploratory aims 
because we have essentially the same power to detect interactions as we do main effects. 
 
Statistical analysis 
For the primary outcome, all statistical analyses will use an alpha level of 0.05. For 
the secondary outcomes and evaluation of moderating effects, multiple comparisons will 
be addressed using the Benjamini-Hochberg procedure to control the false discovery rate 
[58]. Consistent with an intent-to-treat approach, we will assess for any between-condition 
differences in patterns of missing dietary, physical activity and weight data [59] and impute 
missing data using multiple imputation via chained equations if appropriate, after assessing 
for differential patterns of missing data between groups among each of these variables [60]. 
Any differences in demographic, outcome, or key baseline variables between conditions 
will be controlled for. Any continuous outcome variables showing evidence of substantial 
skewness/kurtosis will undergo normalizing transformation. Accounting for estimated 25% 
attrition, power analyses indicated that 288 participants would provide adequate statistical 
power for analyses. 
 
Primary aim and secondary aim 1: evaluating component independent 
efficacy on outcomes—To evaluate the primary aim, we will construct three-level 
multilevel regression models including randomization to each component (i.e., experimental 
condition) as a predictor of percent weight loss, using model specifications described 
elsewhere [61]. The models will take into account nesting of participants within groups 
as well as repeated observations within participants (i.e., time), with covariates included at 
the participant level. The first model will include weight as an outcome and other models 
will include secondary waist circumstance, calorie intake (estimated as a mean daily calorie 
average over each assessment period, using each individual participant’s self-monitoring 
records) and physical activity as outcomes. The experimental condition predictor will be 

effect-coded to reflect which components are “on” vs. “off” in each condition. 
 
Secondary aim 2: evaluating target engagement—To evaluate the main 
effects of randomization to each component on the target engagement measures of that 
component, a three-level multilevel regression model will be constructed nesting time within 
participants and participants within groups. Outcomes will be the target variables at the first 
post-treatment assessment, with experimental condition again effect-coded. To analyze EMA 
data, we will use mean-centered momentary strategy utilization variables as predictors of 
the probability of a dietary lapse (which could include eating a larger meal or snack than 
intended, eating when not intended, or eating a type of food that the participant intended 
to avoid), modeled via generalized linear mixed-effects models using a logit link function 
(which are robust to unbalanced data, assuming data are missing at random). Participants 
completing less than 40% of EMA prompts at a given assessment point will have data for 
that assessment point excluded. Momentary strategy utilization variables will be summed 
across assessment points (baseline, mid-treatment, post-treatment) for each participant. 
 
Secondary aim 3: the moderating effect of susceptibility to internal 
and external food cues—To evaluate the moderating role of susceptibility to internal and 
external food cues on outcomes, interaction terms will be modeled between these variables 
and each of the components in the model described for the primary aim. 
 
Exploratory aim 1: The moderating effect of susceptibility to internal 
and external food cues—To test component interaction effects, higher-order interaction 
terms (e.g., three-way interaction between mindful awareness, willingness, and values) will 
be added to the multilevel models outlined in the primary aim. 
 
References 
 
[1]. Abdelaal M, le Roux CW, Docherty NG, Morbidity and mortality associated with obesity, Ann. 
Transl. Med 5 (7) (2017). 
[2]. Saydah S, Bullard KM, Cheng Y, et al. , Trends in cardiovascular disease risk factors by obesity 
level in adults in the United States, NHANES 1999-2010, Obesity 22 (8) (2014) 1888–1895. 
[PubMed: 24733690] 
[3]. Butryn ML, Webb V, Wadden TA, Behavioral treatment of obesity, Psychiatr. Clin 34 (4) (2011) 
841–859. 
[4]. Forman EM, Butryn ML, Manasse SM, et al. , Acceptance-based versus standard behavioral 
treatment for obesity: results from the mind your health randomized controlled trial, Obesity 24 
(10) (2016) 2050–2056. [PubMed: 27670400] 
[5]. Lillis J, Niemeier HM, Thomas JG, et al. , A randomized trial of an acceptance-based behavioral 
intervention for weight loss in people with high internal disinhibition, Obesity 24 (12) (2016) 
2509–2514. [PubMed: 27804255] 
[6]. Daubenmier J, Moran PJ, Kristeller J, et al. , Effects of a mindfulness-based weight loss 
intervention in adults with obesity: a randomized clinical trial, Obesity 24 (4) (2016) 794–804. 
[PubMed: 26955895] 
[7]. Butryn ML, Forman EM, Lowe MR, Gorin AA, Zhang F, Schaumberg K, Efficacy of 
environmental and acceptance-based enhancements to behavioral weight loss treatment: the 
ENACT trial, Obesity 25 (5) (2017) 866–872. [PubMed: 28337847] 
[8]. Forman E, Butryn M, Juarascio A, et al. , The mind your health project: a randomized controlled 
trial of an innovative behavioral treatment for obesity, Obesity 21 (6) (2013) 1119–1126. 
[PubMed: 23666772] 
[9]. Butryn ML, Godfrey KM, Call CC, Forman EM, Zhang F, Vope SL, Promotion of Physical 
Activity During Weight Loss Maintenance: A Randomized Controlled Trial, Under review, 2021. 
[10]. Paulhus DL, Vazire S, The self-report method, in: Handbook of Research Methods in Personality 

Psychology. 2007 1, 2007, pp. 224–239. 
[11]. Gelfand LA, DeRubeis RJ, Models of specific and nonspecific change mechanisms in mental 
health treatments, Encycl. Clin. Psychol (2014) 1–8. 
[12]. Collins LM, Murphy SA, Nair VN, Strecher VJ, A strategy for optimizing and evaluating 
behavioral interventions, Ann. Behav. Med 30 (1) (2005) 65–73. [PubMed: 16097907] 
[13]. Collins LM, Murphy SA, Strecher V, The multiphase optimization strategy (MOST) and 
the sequential multiple assignment randomized trial (SMART): new methods for more potent 
eHealth interventions, Am. J. Prev. Med 32 (5) (2007) S112–S118. [PubMed: 17466815] 
[14]. Pellegrini CA, Hoffman SA, Collins LM, Spring B, Optimization of remotely delivered intensive 
lifestyle treatment for obesity using the multiphase optimization strategy: opt-IN study protocol, 
Contemp Clin Trial 38 (2) (2014) 251–259. 
[15]. Hayes SC, Strosahl KD, Wilson KG, Acceptance and Commitment Therapy, American 
Psychological Association, Washington, DC, 2009. 
[16]. Hayes SC, Strosahl KD, Wilson KG, Acceptance and Commitment Therapy: An Experiential 
Approach to Behavior Change, Guilford Press, New York, NY, 1999. 
[17]. Linehan M, DBT? Skills training manual, Guilford Publications, 2014. 
[18]. Marlatt GA, Donovan DM, Relapse Prevention: Maintenance Strategies in the Treatment of 
Addictive Behaviors, Guilford press, 2005. 
[19]. Kristeller J, Wolever RQ, Sheets V, Mindfulness-based eating awareness training (MB-EAT) for 
binge eating: a randomized clinical trial, Mindfulness. 5 (3) (2014) 282–297. 
[20]. Forman EM, Butryn ML, Effective Weight Loss: An Acceptance-based Behavioral Approach, 
Clinician Guide, Oxford University Press, 2016. 
[21]. Lillis J, Dallal DH, Forman EM, Innovations in Applying ACT Strategies for Obesity and 
Physical Activity. Innovations in Acceptance and Commitment Therapy: Clinical Advancements 
and Applications in ACT 126, 2020. 
[22]. Group DPPR, The diabetes prevention program (DPP): description of lifestyle intervention, 
Diabetes Care 25 (12) (2002) 2165–2171. [PubMed: 12453955] 
[23]. Association AD, Reduction in weight and cardiovascular disease risk factors in individuals with 
type 2 diabetes: one-year results of the look AHEAD trial, Diabetes Care 30 (6) (2007) 1374– 
1383. [PubMed: 17363746] 
[24]. Association AG, American Gastroenterological Association medical position statement on 
obesity, Gastroenterology 123 (3) (2002) 879–881. [PubMed: 12198714] 
[25]. Catenacci VA, Ogden LG, Stuht J, et al. , Physical activity patterns in the national weight control 
registry, Obesity 16 (1) (2008) 153–161. [PubMed: 18223628] 
[26]. Jeffery RW, Wing RR, Sherwood NE, Tate DF, Physical activity and weight loss: does 
prescribing higher physical activity goals improve outcome? Am. J. Clin. Nutr 78 (4) (2003) 
684–689. [PubMed: 14522725] 
[27]. Kristeller JL, Wolever RQ, Mindfulness-based eating awareness training for treating binge eating 
disorder: the conceptual foundation, Eat. Disord 19 (1) (2010) 49–61. 
[28]. Kristeller JL, Hallett CB, An exploratory study of a meditation-based intervention for binge 
eating disorder, J. Health Psychol 4 (3) (1999) 357–363. [PubMed: 22021603] 
[29]. Daubenmier J, Kristeller J, Hecht FM, et al. , Mindfulness intervention for stress eating to reduce 
cortisol and abdominal fat among overweight and obese women: an exploratory randomized 
controlled study, J. Obes 2011 (2011). 
[30]. Kabat-Zinn J, Full catastrophe living: Using the wisdom of your body and mind to face stress, 
pain, and illness, Delacourt, New York, 1990. 
[31]. Harris R, ACT Made Simple: An Easy-to-Read Primer on Acceptance and Commitment Therapy, 
New Harbinger Publications, 2019. 
[32]. Kohlenberg RJ, Hayes SC, Tsai M, Radical behavioral psychotherapy: two contemporary 
examples, Clin. Psychol. Rev 13 (6) (1993) 579–592. 
[33]. Dallal DH, Forman EM, The Values Interview: Developing and validating a new measure of 
values clarity and values awareness, in: 18th Annual World Conference of the Association for 
Contextual Behavioral Science, 7, 2020. New Orleans, LA. 
[34]. Deci E, Ryan RM, Intrinsic Motivation and Self-Determination in Human Behavior, Plenum, 
New York, 1985. 
[35]. Ryan RM, Deci EL, Intrinsic and extrinsic motivations: classic definitions and new directions, 

Contemp. Educ. Psychol 25 (1) (2000) 54–67. [PubMed: 10620381] 
[36]. Ryan RM, Deci EL, Self-determination theory and the facilitation of intrinsic motivation, social 
development, and well-being, Am. Psychol 55 (1) (2000) 68. [PubMed: 11392867] 
[37]. Center PR, Mobile Fact Sheet, Pew Research Center, 2021. https://www.pewresearch.org/ 
internet/fact-sheet/mobile/?menuItem=d40cde3f-c455-4f0e-9be0-0aefcdaeee00. Published 2021. 
Updated 4 7, 2021. Accessed July 20. 
[38]. Evenepoel C, Clevers E, Deroover L, Van Loo W, Matthys C, Verbeke K, Accuracy of nutrient 
calculations using the consumer-focused online app MyFitnessPal: validation study, J. Med. 
Internet Res 22 (10) (2020), e18237. [PubMed: 33084583] 
[39]. Teixeira V, Voci SM, Mendes-Netto RS, da Silva DG, The relative validity of a food record 
using the smartphone application MyFitnessPal, Nutr. Diet 75 (2) (2018) 219–225. [PubMed: 
29280547] 
[40]. Tosi M, Radice D, Carioni G, et al. , Accuracy of applications to monitor food intake: evaluation 
by comparison with 3-d food diary, Nutrition. 84 (2021) 111018. [PubMed: 33046348] 
[41]. Matthew CE, Calibration of accelerometer output for adults, Med. Sci. Sports Exerc 37 (11 
Suppl) (2005) S512–S522. [PubMed: 16294114] 
[42]. Sallis JF, Haskell WL, Wood PD, et al. , Physical activity assssment methodology in the five-city 
project, Am. J. Epidemiol 121 (1985) 91–106. [PubMed: 3964995] 
[43]. Frisch MB, Cornell J, Villanueva M, Retzlaff PJ, Clinical validation of the Quality of Life 
Inventory. A measure of life satisfaction for use in treatment planning and outcome assessment, 
Psychol. Assess 4 (1) (1992) 92. 
[44]. Cardaciotto L, Herbert JD, Forman EM, Moitra E, Farrow V, The assessment of present-moment 
awareness and acceptance: the Philadelphia mindfulness scale, Assessment 15 (2008) 204–223. 
[PubMed: 18187399] 
[45]. Juarascio AS, Forman EM, Timko CA, Butryn M, Goodwin CL, The development and validation 
of the food craving acceptance and action questionnaire (FAAQ), Eat. Behav (2011) 182–187. 
[PubMed: 21741015] 
[46]. Goodwin CL, Forman EM, Butryn ML, Herbert JD, Ledley GS, Park JA, Yuen EK, Ambani 
R, Project ABLE, An Acceptance-based Behavioral Lifestyle Modification Program for Cardiac 
Patients. A Preliminary Investigation. Poster to be Presented at the 44th Annual Convention of 
the Association for Behavioral and Cognitive Therapies, 2010, 11. San Francisco, CA. 
[47]. Levesque CS, Williams GC, Elliot D, Pickering MA, Bodenhamer B, Finley PJ, Validating the 
theoretical structure of the treatment self-regulation questionnaire (TSRQ) across three different 
health behaviors, Health Educ. Res 22 (5) (2007) 691–702. [PubMed: 17138613] 
[48]. Goldschmidt AB, Crosby RD, Cao L, et al. , Ecological momentary assessment of eating 
episodes in obese adults, Psychosom. Med 76 (9) (2014) 747. [PubMed: 25373891] 
[49]. Thomas JG, Doshi S, Crosby RD, Lowe MR, Ecological momentary assessment of obesogenic 
eating behavior: combining person-specific and environmental predictors, Obesity 19 (8) (2011) 
1574–1579. [PubMed: 21273995] 
[50]. Forman EM, Schumacher LM, Crosby R, et al. , Ecological momentary assessment of dietary 
lapses across behavioral weight loss treatment: characteristics, predictors, and relationships with 
weight change, Ann. Behav. Med 51 (5) (2017) 741–753. [PubMed: 28281136] 
[51]. Lowe MR, Butryn ML, Didie ER, et al. , The power of food scale. A new measure of the 
psychological influence of the food environment, Appetite 53 (1) (2009) 114–118. [PubMed: 
19500623] 
[52]. Seibt B, Häfner M, Deutsch R, Prepared to eat: how immediate affective and motivational 
responses to food cues are influenced by food deprivation, Eur. J. Soc. Psychol 37 (2) (2007) 
359–379. 
[53]. Van Strien T, Frijters JE, Bergers GP, Defares PB, The Dutch eating behavior questionnaire 
(DEBQ) for assessment of restrained, emotional, and external eating behavior, Int. J. Eat. Disord 
5 (2) (1986) 295–315. 
[54]. Robles E, Vargas PA, Functional parameters of delay discounting assessment tasks: order of 
presentation, Behav. Process 75 (2) (2007) 237–241. 
[55]. Logan GD, On the Ability to Inhibit Thought and Action: A users’ Guide to the Stop Signal 
Paradigm, 1994. 
[56]. Dziak J, Collins L, Wagner A, FactorialPowerPlan SAS Macro Suite Users’ Guide, University 

Park: The Methodology Center, Penn State, 2013. 
[57]. Butryn MB, Forman EM, Lowe MR, Gorin AA, Zhang F, Schaumberg K, An Innovative 
Behavioral Treatment Improves Weight Losses for African-American Participants, Under 
Review, 2021. 
[58]. Benjamini Y, Hochberg Y, Controlling the false discovery rate: a practical and powerful approach 
to multiple testing, J. R. Stat. Soc. Ser. B Methodol 57 (1) (1995) 289–300. 
[59]. Hedeker D, Gibbons RD, Application of random-effects pattern-mixture models for missing data 
in longitudinal studies, Psychol. Methods 2 (1) (1997) 64. 
[60]. Van Buuren S, Flexible Imputation of Missing Data, CRC press, 2018. 
[61]. Nahum-Shani I, Dziak JJ, Collins LM, Multilevel factorial designs with experiment-induced 
clustering, Psychol. Methods 23 (3) (2018) 458. [PubMed: 28383950]