Participant engagement with a UK community-based preschool childhood obesity prevention programme: a focused ethnography study.

In summary, participant engagement is affected by multiple factors, working at different levels of the children's centre and local authority hierarchy, most of which are at play even before participants decide whether or not they choose to enrol and maintain attendance. For programmes to achieve their optimal reach and impact, factors at the commissioning and local implementation level need to be addressed prior to addressing participant facing issues.