Abstract
Weight-loss surgical procedures are increasing exponentially in the United States because of the significant increase in morbid obesity. This review examined resting energy expenditure in formally obese patients following elective Roux-en-Y gastric bypass. Conclusions drawn from a variety of studies suggest that energy expenditure adaptations do occur after massive weight loss from both gastric bypass surgical procedures and nonsurgical methods of weight loss. Individual variation in resting energy expenditure was predominately noted in the literature; however, the exact mechanisms contributing to metabolic adaptations remain controversial.