The size of a tummy, expanding on U.S. children in recent years, may be a better measure of health risks associated with obesity, scientists said.

Waist circumference, or tummy size, is a better predictor of diabetes and heart disease than body mass index usually used to measure weight trends, ABCNews.com said. Fat accumulating around the middle is associated with insulin resistance and an increased risk for diabetes.

University of Rochester scientists in New York examined data from the National Health and Nutrition Examination Survey of thousands of children and adolescents, ABCNews.com said. They found abdominal obesity -- excess weight around the middle -- increased between 65 percent and 70 percent in both boys and girls between 1988 and 2004, the years studied. Doctors used the 90th percentile as its benchmark to define abdominal obesity.

Scientists said healthcare providers should monitor waist circumference as well as BMI in both adult and pediatric patients, ABCNews.com said.

Copyright 2006 by United Press International