Changes in fluid compartments and body composition in obese women after weight loss induced by gastric banding.

BACKGROUND/AIMS: Surgical gastric banding procedures induce considerable and rapid weight losses in obese subjects. Nevertheless changes in lean mass and body fluids following these surgical treatments are not well known. METHODS: We studied 6 obese women aged 38-42 years, before, and 8 and 24 weeks after laparoscopic adjustable silicone gastric banding (LAP-BAND(TM)). Fat-free mass (FFM) and fat mass (FM) were investigated using dual energy X-ray absorptiometry (DEXA), while total body water (TBW) and extracellular water (ECW) were assessed by dilution methods. RESULTS: The subjects showed a total weight loss of 16% of initial weight; the weight reduction was greater during the first 8 weeks. FFM decrease after 24 weeks was very limited and represented only 14% of the weight loss. The mean FFM changes per week were similar in the two periods of observation (0-8 and 8-24 weeks after LAP-BAND). TBW showed a global reduction of 2.2 +/- 1.8 litres mainly due to a decline in intracellular water (ICW), while ECW remained constant during weight loss. As a consequence, the ECW/ICW ratio increased after LAP-BAND. CONCLUSION: LAP-BAND seems to achieve satisfactory weight losses while sparing FFM and causing only mild body fluid alterations.