Food Reinforcement, Attentional Bias, and Inhibitory Control as Mechanisms of Energy Compensation With Exercise
Phase: PHASE3
Conditions: Obesity, Weight Loss, Eating Behavior
Sponsor: Kyle Flack

Study Protocol 
Behavioral Mechanism of Energy Compensation with Exercise 
NCT04651218 
October 13, 2022

Visit 1 (week 1). The Study Coordinator will meet with each participant for a 
30-minute orientation session. At this time, participants will have the study 
explained, questions answered, complete the necessary screening 
questionnaires (health history, PAR-Q+), complete an Accu-Check blood 
glucose test, and, if deemed eligible and interested, sign the informed 
consent. Upon enrollment, participants will also complete a food frequency 
questionnaire (DHQ-3), be assessed for body composition (BodPod), and 
have waist circumference measured. Participants will also be provided an 
ActiGraph accelerometer to objectively assess physical activity for the next 
seven days and scheduled for Visit 2 at least eight days later. Participants will 
be instructed not to purposely change dietary behaviors while enrolled in the 
study (i.e. start to diet). 
Visits 2 and 3 (week 2 and 3). On the day of Visit 2, participants will record the 
specific foods, quantities, and time of day they consumed them prior to their 
testing visit. Participants will be instructed to eat the same foods at the same 
time of day prior to Visit 3 as they did prior to Visit 2. Visit 2 and 3 will be 
scheduled at the same time of day on the same day of the week where 
participants will be able to practice "usual" dietary behaviors, i.e. not on a 
holiday or a special occasion. Upon arriving to the LHBP exactly four hours 
post-prandial in the afternoon, participants will complete assessments for food 
reinforcement, attentional bias and inhibitory control for food cues before and 
twice after an acute bout of either exercise or sedentary activity, with one visit 
featuring exercise and the other visit featuring a sedentary activity. The order 
of the visits will be counterbalanced. Visual analog scales (VAS) will be 
performed for hunger and exercise enjoyment prior to each set of 
assessments. For female participants, these visits will occur while in the 
follicular phase, which will be assessed by a mensural cycle questionnaire. 
Participants will wear the accelerometer to record physical activity during the 
washout period between assessment visits and be instructed to remain 
sedentary. 
Acute Bout of Exercise. Participants will complete assessments of food 
reinforcement, attentional bias and inhibitory control before and after an acute 
bout of exercise during Visit 2 or visit 3 (depending on counterbalanced 
order). Participants will be provided a Polar A-300 heart rate monitor with 
smart-cal™ technology that factors the individual's sex, age, weight, activity 
level, and heart rate to produce an estimate of total energy in kilocalories 
(kcal) expended during the exercise session, with kcal expended displayed in 
real- time. Participants will engage in exercise on an elliptical ergometer 
(Octane Fitness ZR8) for the amount of time it takes them to expend 500 kcal 

under supervision of a researcher in the laboratory. Participants will exercise 
at a self-selected intensity of at least 65% heart rate reserve (HRR), an 
intensity commonly prescribed for sedentary individuals beginning an exercise 
program. Based on previous studies conducted in our lab, 500 kcal of energy 
expenditure is attainable for even the most sedentary individual with exercise 
sessions lasting between 30 and 70 minutes depending on body mass and 
intensity of exercise. Prescribing the exercise bout on energy expenditure 
rather than duration or intensity will standardize the amount of total work being 
done across all participants. While both the intensity and duration of the 
exercise could be controlled, due to differences in body mass of the 
participants, either the exercise time or total work would still vary. An energy 
expenditure of 500 kcal is specifically used to ensure the exercise bout is of 
sufficient volume (intensity * time) to produce weight loss if included in a long-
term program and to elicit a dopaminergic response. Participants will be 
permitted to drink 0.5 l of water during and after the exercise bout. 
Participants will take a brief 15-minute rest after completing the exercise 
session before repeating assessments for food reinforcement, attentional bias 
and inhibitory control for food cues (post exercise assessment 1). Participants 
will repeat these assessments 60 minutes after cession of the exercise and 
sedentary activity bout (post exercise assessment 2). 
Acute Bout of Sedentary Activity. Participants will complete assessments of 
food reinforcement, attentional bias and inhibitory control before and after an 
acute bout of sedentary activity (TV). Participants will watch TV for 60 
minutes, choosing from a variety of television sitcoms (DVD) void of 
commercial advertisements that may feature food. Participants will have 
access to 0.5 l of drinking water during and after the test bout of TV viewing.