Childhood obesity is a major public health challenge, and its prevalence and severity are increasing worldwide despite the different actions launched. The aim of this article is to critically review to what extent policies developed at different international institutional levels affecting Spain have effectively translated current research into practice as well as to discuss how the available evidence can serve policy makers. A review of reviews on childhood obesity prevention practices was first performed using MEDLINE and ERIC databases. To select the relevant policies, several experts on childhood obesity prevention were consulted. Results show that, on paper, policies comply with current research recommendations, but in practice there is a gap in how to reach these goals as a role overlap between institutions. Actions need more definition, particularly in the procedural and methodological aspects. Policymakers face numerous barriers to work on this direction, one of the most relevant being the difficulty of implementing systemic policies based upon compartmentalised research. Lessons learned in fields such as community development and education might inform this process.