Abstract Nonalcoholic fatty liver disease (NAFLD) is an obesity-associated liver disease that affects an estimated 7 million children in the United States. It is the most common reason for liver transplantation in adults and increases long term risk of diabetes and cardiovascular disease. NAFLD disproportionately affects Hispanic children and is an exceptionally important health disparity. The original R01 study focuses on use of a low sugar diet intervention for prevention of NAFLD in pre-pubertal children. The proposed administrative supplement studies are designed to expand the project to siblings of the primary participant and to add assessment of response of diabetes risk factors to the intervention. The findings will have sustained and significant implications for health promotion in Hispanic children, reduce health disparities, and inform future prevention efforts for children at increased risk of NAFLD and diabetes.