GPs should measure children's body mass index to help curb the growing obesity epidemic, say leading academics.
Obese children pose the threat of a "disease burden" to the population and parents often do not recognise obesity in their children, they said.
Since children use primary care services about once a year, GPs should use the opportunity to measure their BMI, according to the researchers at University College London's Institute of Child Health.
They made their comments after a study, published on bmj.com, found that obese children have a significantly higher chance of getting heart disease than children of a normal weight.
In an accompanying editorial, Professor Russell Viner and research fellow Lee Hudson write: "The current review provides a stark illustration of the probable threat childhood obesity poses to disease burden in the population.
"Parents often do not recognise obesity or the associated risks," they continued. "Opportunistic measurement of BMI in primary care may be a useful first step in helping families move towards tackling childhood obesity."
The study, conducted by academics at Oxford University, examined data from 63 research papers published between 2000 and 2011, which studied 50,000 children in "highly developed" countries.
They found obese children had several risk factors for heart disease, including raised blood pressure, cholesterol and blood sugar levels.