Children who ate few dairy products and had low or high intakes of dietary fat gained more weight than Sthose on a moderate fat diet, according to a study by American Heart Association.
"The rise in obesity in the nation's young people may be partly due to fewer home-cooked meals, more calorie-dense foods, and more takeout and prepackaged dinners," said Lynn L. Moore, D.Sc., associate professor of medicine at Boston University School of Medicine.
"There has also been a shift toward higher intake of sodas, rather than milk", Lynn further said.
As part of the Framingham Children's Study (FCS), Moore and her colleagues analyzed dietary habits of 106 families with one child 3 to 5 years old at the start of the study. They studied macronutrients such as fat, protein and carbohydrates and micronutrients, such as calcium and other minerals.
The researchers also studied intake of foods in each of the major food groups in the USDA's food guide pyramid and assessed body fat by measurements of children's height and weight as well as skinfolds from five sites on the body.
Children with higher-fat diets (35 percent of calories or more) and lower-fat diets (below 30 percent of calories) gained more weight throughout childhood than those who had moderate intakes of fat (30 to 35 percent of calories).
By early adolescence, children with generally high-fat diets had an average skinfold measurement of 104.6 millimeters (mm) and those with low-fat diets had 92.2 mm. In contrast, children with moderate fat intakes had 74.7 mm of body fat.
"While it is not surprising that children with a high-fat diet had excessive gains in body fat, we were surprised that children on low-fat diets also had excessive gains in body fat," Moore said.
"Animal studies suggest that calcium may play a role in fat metabolism," Moore said. "A diet low in calcium may increase the levels of certain circulating hormones that in turn promote the storage of energy in fat cells. Restricted calcium intake may lead not only to increases in weight and blood pressure, but also to a reduction in bone density in the growing child."
The American Heart Association says the best diet includes a moderate consumption of dietary fat with high intakes of fruits, vegetables and dairy products.