NAFLD is the most common form of liver disease in children in the United States. Currently, there is no treatment for NAFLD. In adults, weight loss through caloric restriction is commonly recommended to improve fatty liver. Weight loss is particularly difficult for children to achieve and significant caloric restriction may not be a prudent recommendation in developing children and adolescents. Because of this difficulty with weight loss in children, many children go on to develop cirrhosis and eventually undergo liver transplant. Data on the effectiveness of diet to reverse fatty liver and prevent progression to cirrhosis in children is urgently needed. To date, no studies have been done examining how changes in diet composition without intentional caloric restriction influences NAFLD in children. Data from previous studies in adults support the hypothesis that consumption of lower-CHO, higher-fat food sources rich in high-quality proteins and essential fatty acids has beneficial effects on metabolic health in adults without restricting calories. This study aims to test the hypothesis that a low CHO higher- fat diet will induce rapid reversal of fatty liver while also depleting of total and abdominal adiposity, preserving lean mass, and reducing inflammation in adolescents with obesity and NAFLD.