Difficulties in recruiting of volunteers with a BMI (Body Mass Index) between 30 and 35 kg/m2

In this study, the investigators are interested in assessing the effects of the isocaloric increase of eating frequency on appetite and metabolism. How the consumption of an isocaloric breakfast in four intakes vs. one can modify satiety and appetite control in lean and obese subjects through :

• the physiological consequences : difference in postprandial kinetics of glucose, non esterified fatty acid, triglyceride, the secretion of satiety gut hormone (insulin, ghrelin, leptin and cholescystokinine (CCK), peptide YY (PYY), glucagon-like peptide-1 (GLP-1), nutrients oxidative fate and plasmatic oxidative stress (Malondialdehyde (MDA), glutathion, lipid hydroperoxides)
• eating behavior during an ad libitum buffet test meal

Inclusion Criteria:

• No smokers
• BMI 20 to 35 kg/m2
• Moderate physical activity
• Safety during medical consultation
• Feeding behavioural phenotype (Dutch Eating Questionnaire, Three Eating Factor Questionnaire)

Exclusion Criteria:

• Medical history which may affect glucose metabolism (diabetes, renal or hepatic failure, thyroid dysfunction, Cushing syndrome, acromegaly…)
• Medical history which affect nutrient absorption (gastro-intestinal and pancreatic disease, gastrectomy, colectomy…)
• Drug use in the last two months that could affect glucose metabolism (steroids, topical gastric preparation, anorectic drugs…)
• Eating disorders
• Claustrophobic subjects