Pedicatric Obesity - Weight - Energy - Loss - Load

After an inclusion visit to ensure the adolescents' ability to complete the entire study, they will then complete 6 experimental visits: i) before their weight loss program (T0); ii) then a visit after a weight loss of 5% (T-5%); iii) after losing 10% of their weight (T-10%); iv) after 12 weeks of treatment (T1); v) after 24 weeks of treatment (T2) and; vi) after 4 months of post-intervention follow-up (T3). During each of these visits, densitometric (body composition and bone structure) and anthropometric (height, body mass, waist circumference, hip circumference) measurements will be taken. Their resting metabolism as well as their energy consumption during a low-intensity incremental walking exercise will be measured by indirect calorimetry. Their sleep metabolism will be assessed over one night using Dreem headbands and their dietary control assessed during a calibrated test meal (satiety quotients and food reward). Their perception of health and quality of life, as well as the perception of their physical condition and their dietary profiles will be evaluated by questionnaire. The cardiovascular profile will also be assessed by measuring sinus variability, hepatic steatosis, arterial stiffness and the resistance and reactance of the respiratory system. Finally, a fasting blood sample will be taken.