Energy expenditure and body composition in severe and morbid obese women after gastric bypass Gasto energético y composición corporal en mujeres con obesidad severa y mórbida sometidas a bypass gástrico

Abstract

Background: The effects of gastric bypass (GBP) on resting energy expenditure (REE) are not well known. Aim: To evaluate the changes in REE and its relationship with body composition in severe and morbid obese women before and six and twelve months after GBP. Patients and methods: Twenty three women aged 37±10 years, with a body mass index of 44±4 kg/m2, were evaluated before, six and twelve months after GBP. REE was measured in a Deltatrac indirect calorimeter and expressed as kcal/day. Fat mass (FM), and fat free mass (FFM) were determined by double beam X ray densitometry (DEXA). Results: Body weight reduction six and twelve months after GBP was 29.0±4.3 and 35.8±6.9%, respectively. The best predictor of weight reduction was initial weight (p <0.01). At six and twelve months, REE decreased by 291.7±260.0 and 353.8±378.4 kcal/day, respectively. In the same periods REE/kg body weight increased by 3.3 and 4.8 kcal/kg respectively, compared to baseline. REE/kg FFM was unchanged. Conclus