Kids who swap out regular dairy products for low-fat forms consume less saturated fat but don't seem to lose weight, according to Australian researchers.
They found neither weight nor body mass index (BMI) had changed noticeably six months after children switched to low- or reduced-fat dairy products.
Instead of trimming their waistlines, kids who slashed fat intake appeared to compensate by eating more calories from other sources, according to the new findings, which appeared online in The American Journal of Clinical Nutrition.
Still, there might be other benefits to cutting back on saturated fat, said Dr Frank Franklin, a retired professor of nutrition and paediatrics at the University of Alabama at Birmingham, who was not involved in the study.
For instance, it might help kids stave off heart disease as they grow up, Dr Franklin said.
For the study, Gilly Hendrie and Rebecca Golley of the Commonwealth Scientific and Industrial Research Organisation divided 145 kids ages four to 13 into two groups. The researchers asked one group to replace their dairy products with low-fat varieties for six months, while the other got no dietary advice.
Both groups consumed similar amounts of dairy products, and the total calorie intake remained more or less stable over the study, which was supported in part by Dairy Australia.
Nurses interviewed the kids and parents on their dairy eating habits at the beginning of the study, and at three and six months. They also drew blood and measured BMI and waist circumference.
The low-fat group did consume less overall fat. At the end of the study, they got 13.3% of their total calories from saturated fat, compared to 16.6% in the comparison group.
This is a significant change, Dr Franklin noted, but still above the 10% recommended by the US Department of Agriculture. He added that American kids generally are closer than Australians to getting the recommended amount.
Drop in cholesterol
There was also a small drop in cholesterol levels in the low-fat group, but their waistline, BMI and weight were no different.
According to Greg Miller of the National Dairy Council (NDC), which represents the industry in the US, this falls in line with other research on kids, where milk shows either a positive or neutral impact on body composition.
"A lot of researchers say that if we just get people to consume low-fat or reduced-fat products, we can have an impact on weight," Miller said.
But as this study shows, the kids made up for the lost calories elsewhere in their diet. So looking at milk alone is not that helpful, Miller said.
Dr Franklin said it's safe to switch to leaner dairy products, which have less cholesterol but the same amount of nutrients, mainly calcium and vitamin D.
"The only thing given up is saturated fat, which you don't need," he said, adding that skim and two-percent milk cost the same as whole milk.
(Reuters Health, Leigh Krietsch Boerner, April 2011)
Diet and nutrition