Understanding childhood obesity in the US: the NIH environmental influences on child health outcomes (ECHO) program.

Background: Few resources exist for prospective, longitudinal analysis of the relationships between early life environment and later obesity in large diverse samples of children in the United States (US). In 2016, the National Institutes of Health launched the Environmental influences on Child Health Outcomes (ECHO) program to investigate influences of environmental exposures on child health and development. We describe demographics and overweight and obesity prevalence in ECHO, and ECHO's potential as a resource for understanding how early life environmental factors affect obesity risk.