Energy Turnover and Appetite (NEXT)

The aim of the study is to compare the effect of a low versus moderate versus high energy turnover on energy intake, appetite and food reward, in adolescents with obesity. 18 adolescents with obesity will then complete three experimental sessions in a randomized order: low, high and moderate Energy turnover.

A total of 18 adolescents with obesity, aged 12-16 years olds will complete three experimental sessions in a randomized order: i) low energy turnover; ii) Moderate energy turnover and ; iii) High energy turnover. Their ad libitum energy intake at dinner will be assessed through an ad libitum buffet-type meal, their food reward assessed right before the dinner meal and their appetite sensation at regular intervals during the day.

There is only one arm as this is an acute randomized study comparing three different conditions within the same sample of participants.

Low Energy Turnover. The adolescents with ingest low energy intake at lunch and breakfast and will not perform physical exercise during the day. The will will receive an ad libitum meal at dinner time. Their food reward will be assessed before dinner. Their appetite feelings will be assessed at regular intervals. Moderate Energy Turnover. The adolescents with ingest moderate energy intake at lunch and breakfast and will perform one 45 minutes physical exercise during the day. The will will receive an ad libitum meal at dinner time. Their food reward will be assessed before dinner. Their appetite feelings will be assessed at regular intervals. High Energy Turnover. The adolescents with ingest high energy intake at lunch and breakfast and will perform two 45-minute physical exercises during the day. The will will receive an ad libitum meal at dinner time. Their food reward will be assessed before dinner. Their appetite feelings will be assessed at regular intervals.

food intake will be measured ad libitum during a dinner buffet. The adolescents will be offered an ad libitum buffet-type meal composed based on their food intake preferences. Their intake will be weighted using an electronic food scale by a member of the investigation team and then analysed using a nutritional software.

: The participants will be asked to complete a validated computer-based procedure to measure food reward (Leeds Food Preference Questionnaire; LFPQ). Briefly, the LFPQ provides measures of the wanting and liking for an array of food images, varying in both fat content and taste.

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