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.

Inclusion criteria

• Subjects aged 12 to 16 years (maturation 3-5 according to Tanner stages), having a body mass index (BMI) greater than the 97th percentile according to national curves.
• Able to give informed consent (parental authorization and assent of the minor) to participate in the research.
• Person subject to a Social Security system

Exclusion criteria

• Medical or surgical history judged by the investigator to be incompatible with the study.
• Presence of diabetes, and any other pathology limiting the application of one or the other strategy being tested.
• Subjects currently undergoing energy restriction or a weight loss program through physical activity at the time of inclusion or during the last 6 months.
• Taking medications that may interfere with study results
• Subjects with cardiovascular problems, we are talking here about subjects with a history of cardiovascular and/or neurovascular pathology, as well as subjects presenting cardiovascular and/or neurovascular risk factors (excluding obesity/ overweight).
• Surgical intervention within the previous 3 months.
• Pregnant or breastfeeding adolescents
• Person under guardianship/curatorship or safeguard of justice
• Participant's refusal to participate
• Refusal of consent (parental authorization) from holders of parental authority
• Person in period of exclusion from another study
• Consumption of tobacco or alcohol.
• Parents under curatorship/tutorship or legal protection.
• Special diet.
• Participation in regular and intense physical and sporting activities for more than two hours per week.
• Refusal of participation by legal representatives.