Dwayne "The Rock" Johnson in an ad for milk. Researchers say… (Uncredited )
This post has been updated to include comments from a researcher and an American Heart Assn. spokeswoman.
Giving toddlers skim or 1% milk to keep them from growing overweight doesn’t seem to work, according to a study out Monday that gives pause over the common advice to avoid whole milk from age 2.
Researchers led by Dr. Mark DeBoer of the University of Virginia School of Medicine looked at 10,700 U.S. children at age 2 and 4, and found that even after adjusting for ethnic and economic factors, the kids who drank skim or 1% milk had higher body mass index scores than those who drank whole or 2% fat milk.
“Compared to those drinking 2%/whole milk, 2- and 4-yer-old children drinking 1%/skim milk had an increased adjusted odds of being over weight or obese,” the researchers wrote in the Archives of Disease in Childhood.
Drinking lower-fat milk was more common among overweight children, but that “does not appear to restrain body weight gain between 2 and 4 years,” the researchers said.
The American Academy of Pediatrics and the American Heart Assn. have recommended 1% or skim milk for children 2 and older to reduce consumption of saturated fat. If a child drinks 3 cups of 1% or skim milk a day, rather than fattier milk, he or she would reduce intake by about 200 calories.
Data on the success of that strategy have been mixed, the authors of the current study wrote. And it’s possible that the parents of children who are more overweight are the ones who are more likely to follow the advice, the researchers noted.
Those who regularly drank 1% or skim milk who were not overweight at age 2 were 57% more likely to be so by age 4, the researchers said.
Linda Van Horne, a spokeswoman for the heart association and a dietitian at the Northwestern University Medical School, noted that the purpose of the heart association recommendation was to curb saturated fat consumption – not as a weight control.
“We need to remember this study was not designed to test this question” of the effects of milk on weight, “and we’re relying on parental reports. And sometimes those are not so good, especially as the child gets older,” she said Monday.
The children in the study were part of the Early Childhood Longitudinal Study, which tracks children, all born in 2001, on a number of factors.
The idea for the study came from a researcher who noticed that it was difficult to find skim milk in her Brooklyn neighborhood that also appeared to be home to many overweight chidren. She wondered if those two things were related, DeBoer said.
The results were surprising, he said Monday. Studies still are needed to pin down the effects of milk. “In isolation, if you keep everything else the same, skim milk is still fewer calories,” he said.
If a child plays outside a lot and eats a balanced diet full of produce and absent juice and soda, it
probably wouldn’t matter much which milk he or she drank, he said, adding that he gave his own children 1% milk.
For this study, parents were interviewed in their homes. And when the children were 4, the parents also were asked about juice, soda, sports and other drinks. The study did not include flavored milks. The children were measured for height and weight.
At 2, 86% of the children drank whole or 2% fat milk; at 4, the total was 81%. Thirty percent of the 2-year-olds were overweight or obese; 32% of the 4-year-olds were. What might be happening, the researchers wrote, is that children who drink fattier milk feel fuller and as a result eat fewer overall calories.
Before parents dump the skim milk down the drain, there are confounding factors, the researchers said. It’s possible that the children who are given lower-fat milk were those who already were overweight. It’s also possible they would have gained even more weight had they had fattier milk.
The researchers suggested that rather than focusing on milk, parents and other care givers might improve toddlers’ health by making sure they watch less television, eat more produce, drink fewer sweetened drinks and get more exercise.
Van Horne agreed that pediatricians should educate families about exercise and broader diet issues.
DeBoar said another paper is coming out that says child who drink very little or a lot of milk are
heavier than children who drink a glass or two a day.
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