Study of the Effects of Time-Restricted Feeding on the Immune Function of Individuals With Obesity

The goal of this randomized trial is to: 1) investigate the immunological landscape of patients with obesity and conduct an in-depth functional characterization of their immune system; and 2) precisely define the effects of time-restricted feeding (TRF) on immune function in patients with obesity; 3) uncover the underlying mechanisms by which TRF modulates the immune system patients with obesity through a multi-omics approach. The main questions it aims to answer are: i) what is the underlying cause of impaired immunocompetence in patients with obesity? ii) how nutritional interventions improve the immune function of patients with obesity? Patients with obesity following TRF (8 h eating window ranging from 6-8 am to 14-16 pm) will be compared to patients with obesity without TRF control schedule (14h eating window ranging from 6-8 am to 8-10 pm). In addition to patients with obesity, the present study aims to recruit a group of a reference healthy group (BMI between 18.5-24.9 kg/m²) that will not receive any nutritional intervention. The following endpoints will be collected: Body weight and composition using Bioelectrical Impedance Analysis, resting energy expenditure (REE) using indirect calorimetry, blood glucose levels using a continuous glucose monitoring (CGM) device, metabolic parameters (fasting blood glucose levels, C-peptide, HbA1c, insulin, HOMA-IR, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, hepatic enzymes), and cytokine profile. Blood and stool, samples will be collected to establish metagenomic, transcriptomic, cytomic and metabolomic analyses.

Inclusion Criteria: Patients with obesity * Women * Age 18-64 years * Body mass Index between 40-50 kg/m² * Self-reported eating pattern window of more than 14h * Three meal eating pattern * Stable body weight (less than 10% of current body weight during the last 3 months) * Social security affiliation * Written consent * Good understanding of the French language Lean patients * Women * Age 18-64 years * Body mass Index between 18.5-24.9 kg/m² * Self-reported eating pattern window of more than 14h * Social security affiliation * Written consent * Good understanding of the French language Exclusion Criteria: * Diabetes type I or II * Major cardiovascular disease * Pregnancy * Medication that could affect the study outcomes (i.e. anti-inflammatory drugs, antibiotics, immunosuppressors) * Use products intended for weight loss * Night work shift * Past record of malignant tumors * Serious liver dysfunction or chronic kidney disease * Eating disorders * Chronic viral disease (Hepatitis B or C, HIV) or inflammatory systemic diseases (i.e. Crohn's disease, rheumatoid arthritis) * Serious cardiovascular or cerebrovascular disease within 6 months before randomization * Severe gastrointestinal diseases or gastrointestinal surgery in the 12 months before randomization * Under guardianship, curatorship, deprived of liberty * Unable or unwilling to sign the informed consent form. * Patient on AME (state medical aid)