Protein Need and Interest of " Quick Proteins " to the Obese Subject Operated by Bariatric Surgery (BIBOP)

The main objective of the study is to evaluate the protein requirement associated with postoperative weight loss caused by by-pass (shunt which leads to a certain degree of malabsorption) or sleeve gastrectomy (more technically conservative with less malabsorption), through the study of nitrogen balance. The benefit of protein supply easily absorbed and with high essential amino acids content (proteins \"fast\" soluble milk) on protein metabolism and muscle function will also be studied. Endotoxemia and intestinal flora variations were measured before and after bariatric surgery.