Few long-term or controlled studies of bariatric surgery have been conducted to date. We report the 12-year follow-up results of an observational, prospective study of Roux-en-Y gastric bypass that was conducted in the United States.

The prevalence of extreme obesity in the United States is increasing at a rate greater than moderate obesity.^1,2 Unfortunately, lifestyle therapy is generally insufficient as a weight management intervention for patients who are extremely obese. To date, effective long-term weight loss through pharmacological therapy has been marginal, leaving bariatric surgery as the only reported medical intervention providing substantial, long-term weight loss for most patients who are severely obese.³ For this high-risk population, however, the number of studies reporting long-term weight loss following bariatric surgery are limited and generally have incomplete follow-up.⁴

The prevalence of chronic disease and physical disability among obese elderly persons is high and increasing.^1,2 The economic burden associated with chronic disease or disability is substantial.^2-4 Although the elderly currently constitute less than 13% of the total population,⁵ they account for approximately 35% of the total personal health care costs.⁶ Projections indicating that the US population 65 years and older will increase from 12% in 2000 to 20% in 2030⁵ underscore the urgent need to develop effective strategies designed to manage the risk factors for disease and disability and thereby improve the overall health and quality of life of older adults.

It is unclear whether chronic exercise without caloric restriction or weight loss is a useful strategy for obesity reduction in obese men with and without Type 2 diabetes (T2D). We examined the effects of exercise without weight loss on total and regional adiposity and skeletal muscle mass and composition in lean men and in obese men with and without T2D. Twenty-four men participated in 13 wk of supervised aerobic exercise, five times per week for 60 min at a moderate intensity (∼60% peak oxygen uptake). Total and regional body composition was measured by magnetic resonance imaging. Skeletal muscle composition was determined using computed tomography. Cardiorespiratory fitness was assessed using a graded maximal treadmill test. Body weight did not change within any group in response to exercise (P > 0.1). Significant reductions in total, abdominal subcutaneous, and visceral fat were observed within each group (P < 0.01). The reduction in total and abdominal subcutaneous fat was not different (P > 0.1) between groups; however, the reduction in visceral fat was greater (P < 0.01) in the obese and T2D groups by comparison to the lean group. A significant (P < 0.01) increase in total skeletal muscle, high-density muscle area, and mean muscle attenuation was observed independent of group, and these changes were not different between groups (P > 0.1). Accordingly, whole body fat-to-muscle ratio was increased (P < 0.01) independent of groups. In conclusion, regular exercise without weight loss is associated with a substantial reduction in total and visceral fat and in skeletal muscle lipid in both obesity and T2D.

Background: The degree to which interindividual variation in the mass of select high metabolic rate organs (HMROs) mediates variability in resting en