UH study finds calcium
helps girls stay trimmerMost of the girls said they got their
calcium from dairy products
A University of Hawaii study of 321 girls ages 9 to 14 found the girls who consumed more calcium weighed less and had lower body fat.
Dr. Rachel Novotny, who led the study, said the findings suggest fairly small increases in calcium would have a positive effect, although calorie intake and physical activity are essential to maintain healthy weight and body fat during adolescence.
As expected, girls who consumed more calories and exercised less were heavier and had more body fat, said Novotny, chairwoman of the UH-Manoa Department of Human Nutrition, Food and Animal Sciences.
Girls who consumed more calcium weighed less on average when the researchers compared girls of comparable age, height, level of maturation, calorie intake and exercise.
It didn't take much calcium to make a difference, Novotny reported.
The girls who consumed an extra serving of calcium -- about a cup of milk or thumb-sized piece of cheese (about 300 milligrams of calcium) -- averaged about 2 pounds lighter and had less body fat, Novotny said.
Most of the girls got their calcium from dairy products, Novotny said. Others got it from enriched foods, such as calcium-fortified orange juice, while others received it from supplements, nuts, green leafy vegetables and other sources.
The findings are consistent with studies on preschool children and women between 30 and 60 years old, Novotny said. The studies showed that calcium increase the body's ability to break down fat and decrease fat synthesis.
The UH study -- the first of its kind on adolescents -- was conducted two years ago and intended to look at how diet and activities influence maturation and bone development, Novotny said.
The analysis included the role of calcium specifically on body weight and fat.
The researchers are following the girls, who were enrolled in Kaiser Permanente-Honolulu health plans in 2000-2001, to try to confirm the results and see if early calcium consumption relates to later body weight and fat, Novotny said.
The findings are significant because 15 percent of America's children and teens are considered obese and high body fat contributes to high blood pressure, heart disease, cancer and diabetes and other diseases, she said.
The girls are white, Asian and mixed ethnicity, Novotny said. The girls didn't know the purpose of the study, but were asked to record their overall diet for three days.
Each girl's weight and the amount of fat just above the hipbone near the belly button were recorded by a researcher.
"We were not trying to change their behavior but look at what they are doing ... what happens to calcium in the body," Novotny said.
Novotny, who is seeking funding for further study on the girls, recently presented the findings at an Experimental Biology 2003 meeting in San Diego as part of the American Society for Nutritional Sciences program.