Effects of weight loss on nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases worldwide, affecting men, women, and children. This is due, in part, to the obesity epidemic, which is associated with increased prevalence of NAFLD. The NAFLD spectrum ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), which is the potentially progressive form. NAFLD is associated with metabolic syndrome and insulin resistance. Treatment recommendations include weight reduction through both diet and physical activity, and weight-loss surgery for extreme obesity. Most medical regimens target components of the metabolic syndrome or oxidative stress associated with the pathogenesis of NASH. These include antiobesity regimens, insulin sensitizers, antihyperlipidemics, and antioxidants. Bariatric surgery is effective for achieving and maintaining weight loss and reversing the complications of metabolic syndrome. On the other hand, the literature lacks well-designed, randomized control trials that assess the efficacy of anti-obesity regimens on histologic and long-term outcomes of NAFLD.