Energy Intake and Energy Deficit in Obese Adolescents (IDEFIX)

Nutritional Responses to Chronic Exercise- Versus Energy Restriction-induced Energy Deficits in Obese Adolescents

Tza Nou - Maison médicale pour enfants et adolescentes - 230, rue Vercingétorix - B.P. 77 - 63150 La Bourboule, SSR Nutrition-Obésité - 33-35 rue Maréchal Leclerc - 63000 Clermont-Ferrand, Laboratoire AME2P. Campus universitaire des cezeaux, 63170 Aubiere, Cedex

The aim of the present study is to compare the effect of two weight loss interventions inducing the same energy deficit but one based on exercise and one using dietary restriction, on appetite control in obese adolescents. Investigator hypothesis that daily energy intake and hunger will be increased in the dietary restriction group but not in response to the exercise program.

The present study will compare the nutritional responses to two 4-month weight loss programs inducing the same energy deficit in obese adolescents, one based on exercise and the other one using dietary restriction. After a first 4-month phase stabilizing the adolescents' daily energy intake and expenditure, half of the sample with increase their physical activity to induce a 10% increase of their daily energy expenditure (maintaining the same energy intake) while the other half will stick with the same physical activity program but reduce their daily intake to match for the same 10% energy deficit. Before, at the end and 4 months after the intervention, Investigator will assess the adolescents' energy intake and appetite control by measuring: ad libitum energy intake, appetite feelings throughout the day, food preferences, food reward. But also all the potential underneath mechanisms based on gastro-peptides and adipokines. Finally, sleep metabolism will be assessed using polysomnography as a potential link between weight loss and appetite control. Body composition, quality of life, aerobic capacities and resting metabolic rate will also be measured at each time point.

DEF-EI : Energy restriction induced energy deficit The content of their energy intake will be decreased by 10% daily compared with the phase one of the protocol (stabilization of intake). This decrease will be allowed by the internship nature of the clinical program; all the meals are prepared and served by the personal of the clinical centre.

DEF-EX : Exercise induced energy deficit While their intake will remain the same as phase 1, they will increase their physical activity energy expenditure by 10% thanks to an increase of their prescribed exercise intensities or durations.

food intake will be measured ad libitum during a lunch time buffet. The adolescents will be offered an ad libitum buffet-type meal composed based on their food intake preferences. Their intake will be assessed by a member of the investigation team

VO2peak will be measured during a graded exhaustive cycling test performed by a specialized medical investigator from the Department of Sports Medicine, Functional and Respiratory Rehabilitation (Clermont-Ferrand University Hospital). The initial power will be set at 30 W for three minutes and followed by 15 W increments every 1.5 minutes.

Triglycerides concentration will be assessed thanks to a fasting blood sample taken by a specialized nurse.

Acylated Ghrelin concentration will be assessed thanks to a fasting blood sample taken by a specialized nurse

A total Quality of life score will be obtain thanks to the "SF36" questionnaire. This is a self-reported questionnaire. A member of the investigation team will be present to help and guide the adolescents if needed

A total Health Perception score will be obtain thanks to the "Health Perception Questionnaire ". This is a self-reported questionnaire. A member of the investigation team will be present to help and guide the adolescents if needed.

Inclusion Criteria: BMI percentile > 97th percentile according to the french curves. ages 12-16 years old Signed consent form being registered in the national social security system no contraindication to physical activity Exclusion Criteria: Previous surgical interventions that is considered as non-compatible with the study. Diabetes weight loss during the last 6 months cardiovascular disease or risks

Roche J, Corgosinho FC, Damaso AR, Isacco L, Miguet M, Fillon A, Guyon A, Moreira GA, Pradella-Hallinan M, Tufik S, Tulio de Mello M, Gillet V, Pereira B, Duclos M, Boirie Y, Masurier J, Franco P, Thivel D, Mougin F. Sleep-disordered breathing in adolescents with obesity: When does it start to affect cardiometabolic health? Nutr Metab Cardiovasc Dis. 2020 Apr 12;30(4):683-693. doi: 10.1016/j.numecd.2019.12.003. Epub 2019 Dec 16.