The nature of dietary lipids, age and perivisceral adiposity could alter the postprandial inflammatory response. It is supposed that there is a relationship between the postprandial inflammatory response and the repartition of fat and lean mass, which could partially explain the muscle mass loss with age.

The aim of this study is to compare the inflammatory response of a normal meal or high fat meal (from different fatty acids sources) between young lean and young obese and aged lean and aged obese men.

32 healthy volunteers will be separated into four groups: 8 young lean men, 8 young obese men, 8 aged lean men and 8 aged obese men. They will come to the center four times after inclusion, with 2 to 4 weeks wash out each time. At the first visit they will undergo different test to evaluate their body composition, glucose tolerance, resting energy expenditure, and muscular strength. At the other three visits, people will undergo a kinetic blood sampling, urine and biopsies of adipose tissue over a period of 8h after ingestion of a test meal. The different meals tested (Oleic acid vs palmitic acid vs no lipid) will be given in a random way over the three visits. Before each of these three visits, a controlled diet will be established. At the last visit body composition and muscular strength will be evaluated.

Inclusion Criteria:

• Subject giving his written informed consent
• Male from 20 to 35 years old and more than 60
• Affiliated to the French National Health Insurance
• Body mass index (BMI) ≤ 25kg/m² and waist circumference ≤94cm ; or BMI ≥ 28kg/m² and waist circumference ≥ 102cm.
• Complete blood count (CBC)-platelet, normal liver function and normal coagulation.
• Serology of Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) negative
• normal Thyroid Stimulating Hormone(TSH)

Exclusion Criteria:

• Previous medical and/or surgery judged by the investigator as incompatible with this study
• Glaucoma
• C-reactive protein > 10 mg/l
• people over 120 kg
• People with triglyceridemia > 3 g/L or with familial hypercholesterolemia
• Fasting glycemia > 1,26 g/l, abnormal Oral Glucose Tolerance Test
• Dietary habits judged by the dietitian as incompatible with the study aim
• Vegetarians
• Nutritional allergies or xylocaïn allergy
• People with eating disorders
• Heavy consumer of alcohol or cigarette
• Practising intensive physical exercise
• People with medication that could interfere with the measured parameters: beta-blockers, statins, anticoagulants, antiplatelet agents, corticosteroids for more than 8 days.
• Depression or psychiatric treatment
• Being under someone's supervision
• Refusal to be registered on the National Volunteers Data file or refusal to sign the consent form
• Being in exclusion on the National Volunteers Data file
• Blood donation into the last two months preceding the study