I am a sociologist of health, migration and child development. My research centers on social determinants of health and welbeing throughout the life course and across settings. I have been engaged in a multi-year project that examines associations between neighborhood built and social environmental attributes and physical activity and obesity in the United States. I also scrutinize disparities in energy balance outcomes by race, ethnicity, immigrant, and legal status and the mediating factors underlying these disparities. My research in China focuses on the effects of socioeconomic status, social relationships, and internal migration on a range of health and well-being outcomes in various age groups. I have also published on family and school contexts of child development in both China and the United States. Most of my research has been supported by funding from the National Institutes of Health or private foundations.