To date, limited studies have examined the impact of federal and state nutrition policies targeting foods and beverages in schools on obesity, and none have specifically focused on children in populations with highest obesity rates: Filipinos, Pacific Islanders and Native American children and those in rural areas. This quasi-experimental study will examine the California competitive food and beverage policies together with the subsequent implementation of new USDA standards to improve school meals to measure their effects on obesity among children at highest risk. Body weight measures will be calculated for diverse children (including Pacific Islanders, Filipinos and Native Americans) who attended California public schools from 2001-2016. Using rigorous methods, the study will estimate the causal effects of the policies on the year to year changes in childhood obesity.