Childhood obesity is one of the most serious challenges of the 21st century and it is vital that evidence-based treatment approaches can be translated into practice to meet public health needs. Yet policy-makers cannot afford to wait for the results of lengthy trials before "probably efficacious" interventions are made available to the public, and the need for a continuous improvement methodology has been highlighted. In this discussion paper, we draw on our experiences of developing and evaluating a family-based childhood obesity treatment intervention to discuss the challenges of meeting research appraisal standards, public health needs and delivery practicalities. Recommendations are made for a shift towards a translational approach that brings together the strengths of hypothesis-driven research and high-quality service evaluation to create reciprocal links between evidence, policy and practice. (Contains 2 tables, 1 figure, and 1 box.)