Children who are too heavy between the ages of 2 to 5 face a five-times-higher risk of being fat as they become teenagers, said a study, underscoring the need to maintain a healthy weight beginning in early childhood.

Dr. Philip R. Nader, at the NICHD in Rockville, Maryland, and colleagues tracked the height and weight of roughly 1,400 healthy subjects starting in infancy through about 12 years of age.

They defined overweight as having a body mass index (BMI) greater than the 85th percentile for age.

Results showed that children who were ever overweight in the preschool years were five times more likely to be overweight at age 12 than the rest of the cohort.

During elementary school years, children who were overweight at 7, 9, and 11 years of age had a 374-fold increased risk of being heavy at age 12 than those who remained below the 85th percentile.

Philip Nader, a professor at the University of California, said that parents should carefully monitor their children's weight and if it is too great they should consult a paediatrician and establish a more healthy diet and exercise regime.

The study in the journal Pediatrics September 2006 issue comes amidst a worldwide epidemic of child obesity.

The World Health Organisation said more than a billion people -- nearly one in six of the world's population -- is overweight, outnumbering the 800 million who are under-nourished.

Source: Xinhua/Agencies