Among girls who didn't eat breakfast cereal frequently, the risk of being overweight increased by 13 percent.

"This is a study of girls during adolescence, from 9 to 19, which is an age range that has not been well studied. This is an age range when a lot of girls put on a lot of weight," said lead researcher Bruce Barton, president of the Maryland Medical Research Institute in Baltimore.

The study was funded by the National Heart, Lung, and Blood Institute (NHLBI), with support from General Mills, the cereal manufacturer. The findings appear in the September issue of the Journal of the American Dietetic Association.

Lower Body Mass Index

Using data from the NHLBI's Growth Health Study, Barton and his team tracked the diets and weight of nearly 2,400 girls beginning when they were between 9 and 10 years of age.

They asked the girls to complete three-day food records -- including foods eaten at breakfast -- at various times over the years and they recorded the girls' weight as measured by BMI.

Breakfast cereal consumption predicted a lower body mass index as the girls moved through adolescence. Those who ate breakfast cereal three days a week or more had a BMI of under 25 -- considered healthy -- while those who never ate it averaged a BMI of 27. (For comparison, a 5-foot, 7-inch woman weighing 160 pounds has a BMI of about 25; obesity is defined as a BMI of 30 or more.)

"Skipping breakfast really came out [as a predictor] of weight gain," Barton said. "I don't know if anyone realized the magnitude of breakfast skipping. By age 19 almost 45 percent were skipping breakfast."

'Marker for a Healthy Lifestyle'

What's the magic?

"Cereal is fairly high in fiber," Barton said. "Fiber fills you up so you don't eat as much at lunch. Probably the other foods you eat with cereal, such as milk and orange juice, help."

"Milk drinking and calcium have been related to more fat burning," he added. "A lot of cereal is fortified with vitamins, minerals, folic acid, calcium and iron. So it creates a much healthier nutrition profile."

The researchers also found that the fat content in the girls' non-cereal breakfasts was 60 percent higher, on average, than that of breakfasts that included cereal.

"Cereal eating is almost a marker for a healthy lifestyle," Barton said. "It sets you up for the day, so you don't overeat."

Another expert, Alicia Moag-Stahlberg, a dietitian and executive director of Action for Healthy Kids, a partnership of organizations focused on the childhood obesity epidemic, applauded the study. "It's not showing cause and effect" between cereal eating and weight control, she noted, "but there is synergy with healthy behavior."

According to Moag-Stahlberg, the study provides "good evidence to show girls, look, you will do better if you eat better and even better if you have cereal."

High Fiber

But what kind of cereal?

"Choose high fiber -- one with three or four grams or more of fiber per serving," advised Amy Jamieson-Petonic, a Cleveland dietitian and a spokeswoman for the American Dietetic Association.

If your teenager balks, preferring a sugary, low-fiber cereal, Jamieson-Petonic suggests small changes. "Mix the cereal half and half for a while," she said.

More information: To learn more about healthy eating, visit the American Dietetic Association.