Current primary care policies aimed at reducing obesity and increasing physical activity in children do not work and are very costly to run, according to research published on bmj.com today.

Family doctor screening and brief counselling is part of national policy to tackle childhood obesity in a number of countries including the UK, US and Australia. While the programmes do not harm children, research led by the Murdoch Childrens Research Institute in Melbourne, Australia, questions whether resources would be better spent on prevention and improving treatment for obesity.

The global long-term physical, emotional, social, reproductive and economic consequences of childhood obesity are likely to be extremely serious, says the study. This has led many countries to endorse screening and counselling programmes aimed at children. However, say the authors, very little evidence exists to show this kind of intervention works.

Lead author, Professor Melissa Wake of the Royal Children's Hospital and Murdoch Childrens Research Institute in Melbourne carried out a large trial (LEAP 2) that tracked the effectiveness of this anti-obesity approach in overweight and obese children.

Wake and her team surveyed almost 4000 children who visited their GP between May 2005 and July 2006. Over 250 overweight or mildly obese children were then selected to be part of the trial, 139 were entered into the intervention group and 119 into the control group. Participants in the intervention group received counselling over a 12-week period and their families were helped to set goals that focussed on changing eating habits and increasing physical activity.