The global prevalence of nonalcoholic fatty liver disease (NAFLD) is estimated to be 25% and continues to rise worldwide in the setting of the obesity epidemic. This increase is especially concerning because NAFLD is often a progressive disease that can be associated with significant complications such as liver cirrhosis, hepatocellular carcinoma, and an increase in liver-related and overall mortality. Because of the devastating complications and comorbidities, NAFLD is a very costly disease for the healthcare system, with estimated annual direct medical costs exceeding $100 billion in the United States alone. Given this progressive course, it is imperative to make the diagnosis in patients with risk factors (metabolic syndrome, weight gain, and insulin resistance/diabetes). Once the diagnosis is made, the focus should shift to treatment and monitoring for the development of associated complications. Given that currently no pharmaceutical intervention is approved for the treatment of NAFLD, focus shifts instead to mitigation of risk factors through avoidance of foods that are rich in red meat, trans fats, refined carbohydrates, and high-fructose corn syrup; are low fiber; and have high energy density. The landmark of treatment, however, continues to be weight loss and improvement of insulin resistance, often through a multimodality approach. The current manuscript reviews the clinical phenotypes of NAFLD, its risk factors, and pathogenesis, as well as treatment options including lifestyle modifications and dietary interventions, medical therapies, endoscopic bariatric interventions, and bariatric surgery. (Nutr Clin Pract. 2020;35:72-84) Keywords fatty liver; insulin resistance; liver cirrhosis; non-alcoholic fatty liver disease; nutrition therapy; weight loss From the