OBJECTIVE: The aim of this study was to determine changes in lean body mass after bariatric surgery. METHODS: This retrospective study reviewed 17 medical records of obese women who underwent banded Roux-en-Y gastric bypass. The medical records contained data collected immediately before and 1, 3, 6 and 12 months after surgery. The data included age, weight, height and lean and fat body mass determined by bioelectrical impedance analysis. RESULTS: The mean age of the patients was 43.1 years (SD=7.7). Body mass index decreased significantly within 12 months of the surgery, going from 51.2 (40.2-74.1) to 33.7 (24.8-53.4)kg/m², as did fat body mass, going from 67.5 (51.2-67.4) to 32.1 (16.4-61.9)kg. In the first month after surgery, lean body mass decreased from M=65.3 (SD=7.6) to M=59.7 (SD=8.1kg), representing a decrease of 8.5%. Lean body mass remained constant after this period. CONCLUSION: Loss of lean body mass may indicate a change in protein metabolism immediately after bariatric surgery, which may result in an unfavorable clinical and nutritional course.
Bariatric surgery; Body composition; Electric impedance; Nutrition, public health; Weight loss
