High-Intensity Interval Training, Appetite, and Reward Value of Food in the Obese

Purpose: Studies on the impact of chronic interval training on appetite in the obese population are scarce. The aim of this study was to determine the effect of 12 weeks of isocaloric programs of moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT), or a short-duration HIIT (1/2HIIT), on subjective feelings of appetite, appetite-related hormones and reward value of food in sedentary obese individuals. Methods: Forty-six sedentary obese individuals (30 women and 16 men), with a BMI of 33.3+/-2.9 kg/m2 and age of 34.4+/-8.8 years were randomly assigned to one of the three training groups: MICT (n=14), HIIT (n=16) or 1/2-HIIT (n=16). Exercise was performed 3 times/week for 12 weeks. Subjective feelings of appetite and plasma levels of acylated ghrelin (AG), polypeptide YY3-36 (PYY3-36) and glucagon-like peptide 1 (GLP-1) were measured before and after a standard breakfast (every 30 minutes up to 3h), before and after the exercise intervention. Fat and sweet taste preferences and food reward were measured using the Leeds Food Preference Questionnaire. Results: A significant increase in fasting and postprandial feelings of hunger was observed with the exercise intervention (P=0.01 and P=0.048, respectively), but no effect of group and no interaction. No significant effect of exercise intervention, group or interaction was found on fasting or postprandial subjective feelings of fullness, desire to eat and prospective food consumption or plasma concentration of AG, PYY3-36 and GLP-1. No changes in food preference or reward over time, differences between groups, or interactions were found. Conclusions: This study suggests that chronic HIIT has no independent effect on appetite or food reward when compared with an isocaloric program of MICT in obese individuals.