The Southern California Children’s Environmental Health Center (SC-CEHC) is a new center established in 2013. Obesity and its metabolic consequences have become critical public health issues. A better understanding of the causes of childhood obesity is needed to develop the effective preventive intervention. Recent studies indicate that early-life exposures to near roadway traffic-related air pollution increase childhood obesity and have the potential to contribute to fat redistribution, systemic inflammation, and metabolic changes associated with increased risk for type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular disease.