Morbidly obesity (body mass index 40 kg/m²), the most serious, is more and more frequent. Cardiovascular diseases are the first cause of morbidity and mortality. An excess of TRL particles is one of the characteristics, represents a major cardiovascular risk factor. The overproduction of the intestinal TRL (which apoprotein B48 is the specific tracer) is recently recognized of insulin-resistance and the atherogenous role of these intestinal TRL has been shown. In front of this important overmortality, the bariatric surgery quickly developed. Three main procedures are performed: 2 based exclusively on the gastric restriction (the adjustable gastric banding and the sleeve gastrectomy) and one associating a malabsorption (the gastric bypass).

It is a monocentric, prospective, comparative study. After identification of the eligible subjects, the kinetics (production and clearance rates) of the intestinal TRL will be performed in the hospital, using a stable isotope method (5,5,5-D3-L-Leucine), in 3 groups of obese patients (12 patients per surgery procedure), before and 6 months after the surgery

Inclusion Criteria:

• Men or women from 18 to 65 years old
• Subject having a BMI included between 35 and 40 kg / m2 associated to at least a comorbidity susceptible to be improved after the surgery
• Subject in failure of a medical treatment, led by an expert in nutrition, associating a dietary coverage and a physical activity adapted for at least 6 months
• Subject without contraindication for 3 studied surgical techniques
• Subject without cardiovascular events 6 months ago
• subject is informed and is consented
• Subject having a biologic balance dating less than 3 months

Exclusion Criteria:

• subject with contraindication for 3 studied surgical techniques
• women pregnant
• subject did not consent and is not informed