Process and impact evaluation of the Romp & Chomp obesity prevention intervention in early childhood settings: lessons learned from implementation in preschools and long day care settings.

Background: The Romp & Chomp controlled trial, which aimed to prevent obesity in preschool Australian children, was recently found to reduce the prevalence of childhood overweight and obesity and improve children's dietary patterns. The intervention focused on capacity building and policy implementation within various early childhood settings. This paper reports on the process and impact evaluation of this trial and the lessons learned from this complex community intervention.