An ACT-Based Physician-Delivered Weight Loss Intervention
Phase: NA
Conditions: Overweight and Obesity, Eating Behavior
Sponsor: McGill University

 
 
 
 
 
 
 
 
An ACT-Based Physician-Delivered Weight Loss Intervention 
Study Protocol 
Frayn, Carrière, & Knäuper 
July 13, 2016 
 
 

Study Protocol 
 
The study was approved by the Research Ethics Board (REB-II) at McGill University 
(Montreal, Canada). Participants provided written informed consent prior to commencing the 
intervention. 
Trial Design 
 
The present study was a two-arm pilot randomized controlled trial conducted from May 7, 
2016 to March 7, 2018. Participants were randomized to eight sessions of either an ACT-based 
intervention aimed at reducing emotional eating or standard care, which involved diet and 
exercise counselling. All outcomes were assessed at baseline and post-intervention. The present 
study aimed to recruit 128 participants (64 per condition), similar to the trial protocol outlined by 
Knäuper et al. (2014). 
Participants 
Participants were adults over the age of 18 with overweight or obesity who were seeking 
treatment for weight loss at a clinic in Toronto, Ontario. Only participants considered to be 
emotional eaters, as assessed by a score of 3.25 or higher on the Dutch Eating Behavior 
Questionnaire (DEBQ), were recruited for the study (van Strien, Herman, Anschutz, Engels, & 
de Weerth, 2012). In addition, participants who did not speak, write, and read in English fluently 
were excluded from the study, as well as those who were pregnant. 
Study Procedures 
Participants were recruited upon initial registration at the weight loss clinic. Those who 
expressed interest to participate were assigned a participant ID number and asked to complete a 
brief prescreen questionnaire to determine their eligibility based on the criteria described above. 
Eligible participants were randomly assigned to either the ACT intervention or control condition 

based on the ID number they had initially received. Participants completed a battery of 
questionnaires both baseline and Session 8. Weight was measured every session.  
Randomization and Blinding 
 
Participants were randomized in 1:1 sequence using a random number generator 
(randomizer.org). Two hundred participant ID numbers (1-200) were randomized prior to study 
commencement and assigned to patients who were prescreened. Due to a high number of 
ineligible participants, an additional 100 ID numbers (201-300) were randomized during the 
recruitment process. Participants retained the same ID number throughout, regardless of their 
eligibility, to simplify the process for administrative staff at the clinics. Participants were blind to 
their condition, but physicians and administrative staff were not blind to participant condition. 
Physicians were not blind to participant condition because they were responsible for delivering 
the ACT intervention or standard care. They were thus required to know the participant’s 
condition in order to deliver the adequate treatment. Administrative staff was responsible for 
providing physicians with this information and organizing study paperwork and thus needed to 
be aware of participant condition as well. 
Physician Training 
 
Physicians were trained in the delivery of the weight loss interventions in a 1-hour Skype 
training session delivered by a clinical psychology PhD student. During this training session, 
each physician was taught how to administer the manualized ACT intervention and provided the 
opportunity to ask questions pertaining to the various skills that they would be required to teach 
their patients. Copies of the manual were provided to physicians to follow during sessions. 
Follow-up training sessions were conducted as necessary to ensure treatment fidelity and clarify 
questions that arose as physicians began delivering the interventions.  

Intervention 
Participants in the standard care condition were provided with diet and exercise 
counselling and psychoeducation from their physicians over the course of 8 sessions, as was 
routinely done at the clinic. Physicians were responsible for facilitating this counselling at their 
discretion, and thus what “standard care” entailed differed based on the physician who was 
administering it. However, standard care did not involve any targeted intervention to reduce 
emotional eating. Thus, in addition to standard care, participants in the ACT condition were 
taught techniques to reduce their emotional eating. All sessions were approximately 5-10 
minutes in length and weight was assessed at each visit. Three overarching skills were taught 
over the course of the ACT intervention: (1) values clarification and commitment, (2) 
metacognitive awareness, and (3) distress tolerance. ACT participants were first taught values 
clarification and commitment techniques, where they reflected on their reasons for losing weight 
and how this would improve their quality of life. Participants were taught the BOLD technique 
(Breathe, Observe sensations, Listen to values, Decide on actions that are in line with values) to 
use their values to make discussions pertaining to avoiding emotional eating (Ciarrochi, Bailey, 
& Harris, 2013). Next, participants were introduced to the concept of metacognitive awareness, 
or recognizing and identifying one’s thoughts, feelings, and emotions. Specifically, participants 
were trained in mindful eating, in order to increase awareness of hunger and satiety cues and 
avoid eating when not physically hungry (Kristeller & Wolever, 2011). Lastly, participants were 
taught to increase distress tolerance in the face of negative emotions that typically led to 
emotional overeating. Participants were taught acceptance techniques (dropping the rope, urge 
surfing) to use when experiencing triggering emotions or cravings (Bowen & Marlatt, 2009). An 

intervention summary can be found in Table 1 and the intervention manual is available upon 
request. 
Throughout the sessions, physicians formed if-then plans with the patients to specify how 
to habitually use the ACT techniques to reduce emotional eating in their everyday lives. At the 
end of each session, participants were given a one-page homework sheet that asked them to 
monitor their behavior and their use of the ACT techniques during the week. Participants were 
instructed to bring the homework back with them for the next session so that it could be 
reviewed with their physician.  
Measures 
 
Demographics. At baseline, participants reported basic demographic information 
including gender, age, English fluency, ethnicity, marital status, educational attainment, 
employment status, household income, and whether or not they smoked. 
 
Anthropomorphic measures. Weight was measured at each of the eight sessions 
(primary outcome). Participant body fat percentage was assessed and recorded by their physician 
at baseline and at completion of the eight sessions (secondary outcome).  
 
Emotional, restrained, and external eating. Participants were pre-screened for 
emotional eating using the Dutch Eating Behavior Questionnaire (DEBQ; van Strien et al., 
1986). The DEBQ is a 33-item questionnaire that assesses three dimensions of eating behaviors: 
emotional eating (primary outcome), restrained eating (secondary outcome), and external eating 
(secondary outcome). The emotional eating subscale assesses the reported desire to eat under 
specific negative emotional conditions such as stress, anxiety, and depression. The DEBQ has 
high internal consistency and factorial validity (van Strien et al., 1986). The DEBQ was 
administered again post-intervention. 

 
Distress tolerance. The Distress Tolerance Scale (DTS; Simons & Gaher, 2005), a brief 
self-report questionnaire that assesses one’s ability to tolerate distressing emotions, was 
completed at baseline and post-intervention (secondary outcome). The scale is made up of items 
that assess the dimensions of distress tolerance, absorption, appraisal, and regulation. The DTS 
has high reliability and high discriminant, convergent, and criterion validity (Leyro, Bernstein, 
Vujanovic, McLeish, & Zvolensky, 2011; Simons & Gaher, 2005).  
 
Mindfulness. At both time points (i.e. baseline, post-intervention) participants completed 
the Philadelphia Mindfulness Scale (PHLMS; Cardaciotto, Herbert, Forman, Moitra, & Farrow, 
2008), a 20-item self-report questionnaire that assesses two components of mindfulness: present-
moment awareness and acceptance (secondary outcome). The scale has been shown to have good 
internal consistency and construct validity (Cardaciotto, Herbert, Forman, Moitra, & Farrow, 
2008).  
 
ACT application. At baseline and post-intervention participants filled out a self-report 
questionnaire designed to assess the extent of the participant’s use of ACT strategies to reduce 
emotional eating (secondary outcome). This questionnaire was developed for the present study to 
evaluate participants’ real world application of the intervention. Participants were asked to 
indicate their level of agreement on a 5-point scale (1 = strongly agree and 5 = strongly disagree) 
to prompts such as “My values motivate me to lose weight” and “I am able to accept negative 
emotions and don’t have to eat when I’m feeling bad”.  
 
Treatment satisfaction. After the eighth session, participants completed a brief, self-
developed questionnaire to assess their overall satisfaction with the intervention. Participants 
were asked to indicate their level of agreement on a 5-point scale (1 = strongly agree and 5 = 
strongly disagree). Physicians were also asked to complete a similar questionnaire at various 

points throughout the intervention to obtain their input on its feasibility and efficacy of the 
intervention. Open-ended feedback was also collected from physicians, asking for their 
suggestions on ways to improve the intervention, and to provide insight on patient dropout/non-
responsiveness. 
Data Analysis 
 
All analyses were conducted in SPSS version 24. 2 Two separate 2 (Condition: Standard 
Care, ACT Intervention) x 2 (Time: Baseline, Session 8) repeated measures MANOVAs were 
conducted for the anthropomorphic and questionnaire data outlined above, respectively, with 
follow-up t-tests conducted as necessary. Two separate MANOVAs were conducted to not lose 
data from incomplete cases (i.e., participants who had completed anthropomorphic but not 
questionnaire data). Independent samples t-tests were conducted for treatment satisfaction data 
collected at Session 8, whereas chi-square tests were conducted to compare recruitment rates, 
attrition rates, questionnaire completion, and intervention completion time between conditions. 
Missing data were not imputed because of the large drop out rates: Imputation with small sample 
sizes and high rates of missingness has been shown to be highly prone to Type I error (McNeish, 
2016). 
 
 

References 
Bowen, S., & Marlatt, A. (2009). Surfing the urge: brief mindfulness-based intervention for 
college student smokers. Psychology of Addictive Behaviors, 23(4), 666-671. 
Cardaciotto, L., Herbert, J. D., Forman, E. M., Moitra, E., & Farrow, V. (2008). The assessment 
of present-moment awareness and acceptance: The Philadelphia Mindfulness 
Scale. Assessment, 15(2), 204-223. 
Ciarrochi, J., Bailey, A., Harris, R. (2013). The choice point model: An introduction [PowerPoint 
slides]. Retrieved from: https://contextualscience.org/choice_point_model  
Knäuper, B., Ivanova, E., Xu, Z., Chamandy, M., Lowensteyn, I., Joseph, L., Luszczynska, A., & 
Grover, S. (2014). Increasing the effectiveness of the Diabetes Prevention Program 
through if-then plans: Study protocol for the randomized controlled trial of the McGill 
CHIP Healthy Weight Program. BMC Public Health, 14, 470. 
Kristeller, J., & Wolever, R. Q., (2011). Mindfulness-based eating awareness training for treating 
binge eating disorder: the conceptual foundation. Eating Disorders, 19(1), 49-61. 
Leyro, T. M., Bernstein, A., Vujanovic, A. A., McLeish, A. C., & Zvolensky, M. J. (2011). 
Distress Tolerance Scale: A confirmatory factor analysis among daily cigarette 
smokers. Journal of Psychopathology and Behavioral Assessment, 33(1), 47-57. 
Simons, J. S., & Gaher, R. M. (2005). The Distress Tolerance Scale: Development and validation 
of a self-report measure. Motivation and Emotion, 29(2), 83-102. 
van Strien, T., Frijters, J. E., Bergers, G., & Defares, P. B. (1986). The Dutch Eating Behavior 
Questionnaire (DEBQ) for assessment of restrained, emotional, and external eating 
behavior. International Journal of Eating Disorders, 5(2), 295-315. 

van Strien, T., Herman, C. P., Anschutz, D. J., Engels, R. C., & de Weerth, C. (2012). 
Moderation of distress-induced eating by emotional eating scores. Appetite, 58(1), 277-
284. 
 

Table 1. Intervention summary 
 
Session 
Session Content 
Homework 
 
1 – Emotional eating 
 
The patient and physician discussed 
emotional eating and what emotions 
lead to the patient overeating, and 
what situations in the patient’s life 
lead to these emotions. They went 
over the patient’s DEBQ results to 
determine what emotions they scored 
the highest on. 
 
 
The patient kept an emotional 
eating diary for 1 week, where 
each time the patient overate 
they wrote down the emotions 
they felt before and after 
overeating, as well as whether 
or not they were truly hungry. 
2 – Values 
The patient and physician discussed 
what core values are. They discussed 
why the patient wanted to lose 
weight and why weight loss is 
important to them, as well as how 
their values are related to emotional 
eating and how emotional eating 
may hinder their weight loss 
progress. 
 
The patient wrote down their 
reasons for wanting to lose 
weight and how these reasons 
are related to emotional eating. 
3 – Using values to 
make decisions 
The patient and physician briefly 
reviewed the patient’s values related 
to losing weight. The physician 
taught the patient the BOLD 
technique and how to use it to reduce 
emotional eating, as well as 
introduced if-then plans and how 
they can be used to reduce emotional 
eating. 
The patient practiced following 
if-then plans (IF I want to eat 
when I experience ______ 
emotion, THEN I will use the 
BOLD technique). They 
journaled their observations 
from a time when the BOLD 
technique was used to reduce 
emotional eating. 
 
4 – Acceptance 
The patient and physician discussed 
the concept of accepting and 
tolerating negative emotions. The 
tug-of-war metaphor and the concept 
of dropping the rope in the face of 
negative emotions was introduced. 
They brainstormed alternative ways 
to respond to negative emotions 
(instead of eating). 
The patient practiced dropping 
the rope and finding alternatives 
to eating in response to negative 
emotions. The patient used the 
if-then plan “IF I feel _____ 
emotion, then I will practice 
dropping the rope and do 
(alternate behaviour) instead of 
eating”. They journaled a time 
when this occurred doing the 
week and what the experience 
was like. 

5 – Urge surfing 
The patient and physician discussed 
the concept of urge surfing and how 
it can be used when experiencing 
emotions or cravings to prevent 
overeating. 
The patient practiced urge 
surfing using the if-then plan 
“IF I feel ______ emotion, 
THEN I will practice urge 
surfing”. They journaled a time 
during the week when urge 
surfing was used and what the 
experience was like. 
6 – Mindful eating 
The physician explained the concept 
of mindful eating and how to do it. 
They completed a mindful eating 
exercise to train the patient in how to 
prevent mindless eating. 
The patient practiced mindful 
eating at home. They used the 
if-then plan “IF I want to eat my 
favourite treat, THEN I will 
practice eating it mindfully”. 
They journaled a time during 
the week when mindful eating 
was used and what the 
experience was like. 
 
7 – Establishing habits The physician reviewed the skills 
taught in the first six sessions to help 
reduce emotional eating and promote 
long-term weight loss. They 
discussed the techniques that the 
patient found most useful and 
emphasized the importance of 
practicing these skills routinely to 
establish a habit.  
 
The patient chose the if-then 
plans that worked best for 
reducing their own emotional 
eating and wrote them down. 
They tailored them to the 
emotions the patient finds most 
triggering.  
8 – Commitment to 
values 
The patient and physician discussed 
setbacks, loss of motivation, and 
how they are a normal and inevitable 
part of the weight loss journey. They 
discussed ways to stay committed to 
values and goals despite setbacks. 
The if-then plans the patient had 
chosen as the most effective were 
reviewed. The patient wrote those 
plans on a summary card. 
The patient was encouraged to 
keep the summary card of if-
then plans somewhere 
accessible to act as a constant 
reminder of values when feeling 
a lack of motivation.