Body Composition After Stomach Bypass Weight Loss Operations
About Body Fat After Bypass
| Bariatric Surgery information Body Composition After Stomach Bypass Weight Loss Operations |
About Body Fat After Bypass |
| Body Composition After Stomach Bypass Surgery Body composition methods were examined in 20 women [body mass index (BMI) 48.7] before and after weight loss [-44.8 +/- 14.6 (SD) kg] after gastric bypass surgery. Method and Result The reference method, a three-compartment (3C) model using body density by air displacement plethysmography and total body water (TBW) by H(2)18O dilution (3C-H(2)18O), showed a decrease in percent body fat (%BF) from 51.4 to 34.6%. Fat-free mass hydration was significantly higher than the reference value (0.738) in extreme obesity but not after weight reduction (0.747; P = 0.16). %BF by H(2)18O dilution and air displacement plethysmography differed significantly from %BF by 3C-H(2)18O in extreme obesity and 3C models using (2)H(2)O or bioelectrical impedance analysis (BIA) to determine TBW improved mean %BF estimates over most other methods at both time points. BIA results varied with the equation used, but BIA better predicted %BF than did BMI at both time points. All methods except BIA using the Segal equation were comparable to the reference method for determining changes over time. A simple 3C model utilizing air displacement plethysmography and BIA is useful for clinical evaluation in this population. Source: Gastric Bypass Surgery to Reduce Obesity |