 Objectives: The main objective of this study is to compare the effect of each surgical procedure and the differential effect of the 2 bariatric surgery procedures on the production and clearance rates of the intestinal TRL. The secondary objectives are to compare the effect of each surgical procedure and the differential effect of the 2 bariatric surgery procedures on the production and clearance rates of the hepatic TRL and to document the potential links between the expected reduction of these productions after the surgery and the loss of weight, the improvement of the insulin-sensitivity, the changes in hormones, the decrease of the inflammatory state, the changes in energy expenditure, body composition and energy intake. 