To identify key barriers to effective engagement of primary health care (PHC) providers and families in promoting healthy weight among children aged 2–6 years, and to examine promising interventions to identify policy goals to overcome these barriers.

We conducted a literature review of published and unpublished articles from January 1990 to February 2006 using keywords relating to childhood obesity, risk factors, prevention, populations and primary care provider interventions, constraints and models. We identified barriers to engagement by PHC providers. Appraisal of “promise” was based on best available evidence and consideration of strengths and weaknesses of interventions in specific contexts and settings.

Of 982 interventions aimed at the primary prevention of overweight and obesity among children, few related to 2–6-year-olds, with only 45 interventions meeting the inclusion criteria and 11 ranking highly on key criteria. Areas of weakness were low-level engagement by PHC providers, focus on single risk factors rather than a multidimensional approach, and lack of a population focus. A range of administrative, attitudinal, knowledge, skills and training issues were identified as barriers to effective engagement of different PHC providers with parents and other early childhood service providers.

Engagement of PHC providers in prevention of childhood obesity requires a systematic approach involving practice protocols, assessment tools, client support material and referral pathways, as well as adequate training and sufficient staff for implementation. A more comprehensive approach could be promoted by increased collaboration, agreed role delineation, consistent public health messages and better coordination between PHC providers and other service providers, facilitated at service policy and administration level.