Body composition, anthropometrics, energy expenditure, systemic inflammation, in premenopausal women 1 year after laparoscopic Roux-en-Y gastric bypass

Background Laparoscopic Roux-en-Y gastric bypass (LRYGBP) is currently the most common bariatric procedure and results in a substantial weight loss and recovery from obesity-related comorbidities, both of which are maintained in the long term. However, besides the desired loss of fat mass, LRYGBP is also followed by the loss of fat-free mass (FFM). We aimed to determine the factors associated with the loss of ≥20 % of the initial FFM 1 year after LRYGBP in a prospective series of 115 Caucasian, premenopausal women. Methods Anthropometrics, body composition (bioelectrical impedance analysis), resting energy expenditure (REE) (indirect calorimetry), inflammation, insulin resistance, and lipid disturbances were determined before and 1 year after LRYGBP. Results The mean loss of initial FFM was 15.3 ± 13.8 %. 1 year after LRYGBP, 81 women lost