"Dairy and calcium intake is associated with the level of fat and weight among adolescent girls," says lead author Rachel Novotny, a nutritionist at the University of Hawaii. Similar findings have been found in animals, adults and in very young children, but this is the first time it has been found in young girls, she adds. These findings support the idea that calcium, especially from dairy products, helps control weight and fat.
Novotny and her colleagues from the University of Hawaii at Manoa in Honolulu studied 323 girls, aged 9 to 14 years old. The researchers collected data on what the girls ate and their amount of physical exercise. They also measured the girls' weight and the amount of fat just above the hipbone near the bellybutton. This so-called "skin fold thickness" measures abdominal fat.
Naturally, the girls who consumed the most calories and did the least physical exercise weighed more and had more body fat. However, after Novotny's team looked at calcium intake, they found that despite differences in calorie intake and amount of exercise, girls who consumed more calcium weighed less than girls who consumed less calcium.
In fact, the investigators found that as little as a daily increase of one cup of milk or a small piece of cheese, about 300 milligrams of calcium, resulted in one-half inch less of abdominal fat and as much as two pounds less of body weight. "I have reason to believe that the same effect occurs in boys," Novotny says.
Novotny presented her findings on April 13 as part of the American Society for Nutritional Sciences program at the Experimental Biology meeting in San Diego.
Over the past several decades, the consumption of dairy foods in the United States has decreased, Novotny says. "This may be contributing to our high levels of obesity. These findings could have a measurable impact on levels of weight," she adds.
People should be encouraged to add more dairy to their diet, which will help them control weight throughout their lives, Novotny says.
"This study presents exciting results that adds to the previously published literature on the effects of higher calcium or dairy intake on body composition, particularly fat mass," says Dorothy Teegarden, a professor of nutrition at Purdue University.
She adds the result of this study provides further evidence that higher calcium intake may play an important role in reducing the growing problem of obesity in the United States, particularly in children.
However, Dr. Robert P. Heaney, a professor of medicine and bone expert from Creighton University, cautions that while high calcium intake can help, "nothing will help you if you eat too much."