Obesity, a growing epidemic in the developing world, is associated with numerous comorbidities.

This chapter reviews the current literature on the effects of weight loss on obesity and its comorbidities and focuses on the long-term efficacy of treatment modalities including behavioral modifications, pharmacotherapy, and bariatric surgery.

Behavioral modifications including diet and exercise are first-line recommendations from the US Preventative Services Task Force and are associated with improvement in numerous comorbidities including body weight, lipid profile, blood pressure, and glycemic control; however, long-term compliance and sustainability has been an important issue.

Currently, there are only two medications approved by the FDA for weight loss. While short-term data are promising, there is limited long-term data on weight loss and other comorbidities of obesity.

For certain subgroups of obese patients, bariatric surgery yields dramatic and sustained effects on weight loss as well glycemic control and other comorbidities, and recent data suggests an improvement in long-term mortality associated with bariatric surgery; however, given the invasiveness and potential complications of bariatric surgery, more studies will be needed to clarify its future role in obesity treatment.