TREating Pediatric Obesity

Inclusion criteria

• Age between 10 and 15 at the start of the study.
• Obesity defined according to the criteria of the World Health Organization (BMI≥p95) and at least one of the following conditions:

2.1. Hepatic steatosis confirmed by abdominal ultrasound in the previous 12 months.

2.2. Triglycerides> 150 mg/dl, confirmed in analytical determination in the 4 weeks prior to the start of the study.

2.3. HDL cholesterol <40 mg/dl, confirmed in analytical determination in the 4 weeks prior to the start of the study.

2.4. LDL cholesterol> 135 mg/dl, confirmed in analytical determination in the 4 weeks prior to the start of the study.

2.5. Insulin resistance, determined by elevated HOMA-IR confirmed by analytical determination in the 4 weeks prior to the start of the study.

• Habitual eating window equal to or greater than 13 hours, with a response rate greater than 85%. Habitual eating window will be determined by self-registration during the screening process. Participants must properly record the habitual eating window in at least 12 of the 14 days that self-registration will be requested, and it must be equal to or greather than 13 hours at least 6 days a week.
• Reporting to have maintained a stable weight and height status during the last two months (changes of less than 2 points in BMI (kg / m2)).
• Agreement to participate in all phases and procedures of the study.

Exclusion criteria

• Being diagnosed with an endocrine disorder, for example, diabetes mellitus under treatment with insulin or oral antidiabetics, thyroid disease, hypercortisolism, congenital adrenal hyperplasia.
• Being diagnosed with a chronic digestive, rheumatological, neurological, cardiological, pneumological, autoimmune or infectious disease that affects energy metabolism.
• Having undergone a surgical procedure that chronically alternates digestive or metabolic function.
• Hypercholesterolemia requiring pharmacological treatment according to the Expert Consensus of the European Society of Arteriosclerosis specific to children.
• Serum triglyceride concentration> 500 mg/dl.
• Systolic or diastolic blood pressure values equal to or greater than the specific 95th percentile for age, sixth, and height, on 3 different occasions [42].
• Hypertransaminasemia> 200 IU / L (5 times higher than the upper normal value in the laboratory), which would make it necessary to rule out other causes of liver disease.
• Being diagnosed with an eating disorder or being at risk of developing these disorders, determined using the SCOFF questionnaire (two or more questions answered positively).
• Presenting neurological alterations or chromosomopathies.
• Consuming drugs or supplements that are likely to alter energy metabolism.
• Being participating in a nutritional intervention or treatment of any kind, or having done so during the previous 3 months.
• Having a demonstrable personal or professional relationship with any of the members of the investigation team.
• Any other condition that in the opinion of the research team would contraindicate their participation.