Widespread public concern with obesity means children are seen as advocates for change in family health practices. This qualitative study examines how health knowledge taken home by primary aged children impacts on children's well-being, family food practices, and family relationships. It investigates the consequences for children and families of primary school healthy eating programs, with particular attention to diverse family groups. It uses a multi-method qualitative approach including video diaries, and interviews with children and parents within families. Results will inform and school health and education policy practices, and provide resources for those working on health issues with primary school aged children and families.