NEW DELHI -- Children studying in expensive private schools in Delhi were much fatter than pupils of government-run schools, according a study reported recently.

The study conducted by the city's All India Institute of Medical Sciences (AIIMS) said 21 percent of the boys and 22 percent of the girls covered by the study were overweight.

The study published by the ****Hindustan Times***** newspaper said children in government run schools were in much better shape but refrained from making any socio-economic categorization.

The study said private-school children were overweight because they had access to canteen facilities and frequented fast food joints more often. The canteens tended to serve fatty foods like chips and burgers, DPA reported.

AIIMS dietician Rekha Sharma said the private school pupils had low counts of high density lipoproteins (HDL) popularly known as good cholesterol, which prevents heart attacks.

The study found that the private school children had a high intake of saturated fats and low intake of mono-saturated fats which are best for health.

But the biggest factor contributing to obesity among children was that they lacked physical activity. "All they do is study, watch TV and play on the computer," Sharma said.