Asian children do the least physical exercise among New Zealand schoolchildren, and Indian children have the highest levels of body fat, a study of childhood obesity shows.

Researchers at the Auckland University of Technology (AUT) found that although Indian children were among the lightest for their height, they had the highest percentage of body fat.

AUT researcher Scott Duncan, who is presenting the findings from the Body-size and Steps in Children (Basic) Study at the Asian Women's Health Symposium in Auckland today, said it was a problem that needed urgent attention.

The way Indian children stored fat was particularly alarming, he said.

"Indian people have a tendency to store fat around the middle as opposed to the hips, which is a risk factor for cardiovascular disease."

Asian parents tended to emphasise academic achievement over sport activity, thus contributing to the low level of physical activity among their children.

Furthermore, because Asian people tended to have less muscle mass and smaller frames, obesity problems were often hidden.

While childhood obesity in New Zealand was not as bad as in some countries, it was increasing.

"The physical activity and sport message needs to be hammered home for Asian parents and children.

"We need to start addressing these problems in an ethnic-specific manner."

The Basic study involved a random sample of 1200 Auckland primary school children during 2004, and included assessments of physical activity using pedometers, dietary patterns using a parent questionnaire and body fat measurements.

Wellington dietitian Vicki Robinson said many migrants to New Zealand experienced significant weight gains due to the changes in diet and lifestyle.

"They go from a traditional diet based on rice and vegetables to our high-fat New Zealand diet, heavy on meat and dairy products. Furthermore, they often have a more sedentary lifestyle."

Childhood obesity heightened the risk for a number of serious health problems in later life, including heart problems and diabetes, she said.