FRIDAY, Oct. 1 (HealthDay News) -- Nutrition experts have examined the diets of typical U.S. children and they don't like what they see: Almost 40 percent of the kids' calorie consumption comes from solid fat and added sugars.

These so-called "empty calories," mainly in soda, pizza and desserts, are fueling the obesity epidemic among young people and putting them at risk for developing weight-related illnesses, such as diabetes and heart disease, the U.S. government researchers said.

"Product reformulation alone is not sufficient -- the flow of empty calories into the food supply must be reduced," said dietitians Jill Reedy and Susan M. Krebs-Smith, from the U.S. National Cancer Institute's division of cancer control and population sciences in Bethesda, Md.

The findings are published in the October issue of the Journal of the American Dietetic Association.

The researchers examined data from the National Health and Nutrition Examination Survey and calculated solid fats and added sugars using the USDA MyPyramid Equivalents Database, according to a news release from the journal publisher and the American Dietetic Association.

The top sources of energy for 2- to 18-year-olds were grain desserts, pizza and soda, they found. Sugar-sweetened drinks (soda or fruit drinks) provided nearly 10 percent of total caloric intake. Half of the kids' empty calories came from these six foods: soda, fruit drinks, dairy desserts, grain desserts, pizza and whole milk.

Energy sources varied depending on age. The top five sources of energy for toddlers (2- to 3-years old) included whole milk, fruit juice, reduced-fat milk, and pasta and pasta dishes. The top five choices among 4- to 8-year-olds also included pasta and reduced-fat milk, the investigators found.

Energy sources also varied by race and ethnicity, the dietitians noted. Among black children, fruit drinks and pasta and pasta dishes were the primary energy sources, while Mexican American kids' top sources included Mexican mixed dishes and whole milk. Blacks and whites consumed more energy from soda and fruit drinks than from milk, whereas Mexican American children obtained more energy from milk than from sugary drinks, the data showed.

Added sugar is especially damaging, according to Dr. Rae-Ellen W. Kavey, a pediatric cardiologist at the University of Rochester Medical Center, who wrote an accompanying commentary in the journal. Health consequences include accelerated atherosclerosis and early cardiovascular disease, Kavey said in the news release.

"Reducing consumption of sugar-sweetened beverages should be considered a critical dietary approach to reducing cardiovascular risk in childhood," Kavey added.

A second study in the journal found that vending machines in middle schools attract students mainly to buy snacks and beverages, even if healthier choices are offered.

More information

For tips on helping your overweight child, see the U.S. National Institute of Diabetes and Digestive ... Kidney Diseases.