Vending Machines Found in Most Midd...( change snack and desert foods to 200 ca...),Health

But these steps may not be enough, according to Roberta H. Anding, a clinical dietitian at Texas Children's Hospital. The 300-calorie-a-day increase in children's diets since the 1970s comes from more refined carbohydrates and fats, she said. Schools need to make the right choices to implement these changes.

"If the focus is just on calories, it might give a stamp of approval to a reduced-calorie snack that is trans fat- and white flour-rich", she said. "Research suggests that those who eat whole grains instead of highly processed food decrease the risk of diabetes. These whole grains are rich in magnesium, which also is protective against diabetes."

The number of vending machines in schools has doubled since the 1990s, Virus noted.

"If a child has a dollar in their pocket or a dollar and twenty-five cents, they want to spend it," she said. "If they can only choose from healthy products, hopefully, we'll see a difference in their risk factors for obesity and type 2 diabetes."

More information

The U.S. Centers for Disease Control and Prevention has more on childhood obesity.

SOURCES: Roberta Anding, M.S., R.D., L.D., C.D.E., clinical dietitian, Adolescent Medicine and Sports Medicine clinics, Texas Children's Hospital, national spokesman, American Dietetic Association, and sports dietitian, Houston Texans NFL franchise; Amy Virus, R.D., L.D.N., research dietitian, Center for Obesity Research and Education, School of Medicine, Temple University, Philadelphia; Oct. 6, 2008, presentation, Obesity Society annual meeting, Phoenix