'A Calorie Is a Calorie'
The research was funded by the Dairy Council and an interview with Zemel appears on the Council's weight loss web site.
"When your body doesn't get enough calcium, it starts a defense mechanism to preserve what calcium it does have," he is quoted as saying. "It's actually a hormonal response that increases the amount of fat stored and slows down the process that breaks it down for energy. So if you increase calcium, less fat is stored and more fat is burned."
But nutrition expert Alice Lichtenstein, DSc, tells WebMD that she has seen nothing to convince her that any single nutrient or nutrient mix holds the key to easy weight loss.
Lichtenstein directs the Cardiovascular Nutrition Laboratory at Boston's Tufts University.
"There just isn't convincing evidence that any combination of foods or nutrients helps people burn fat quicker," she says. "You can't beat the system. When it gets right down to it, the best evidence that we have right now suggests that a calorie is a calorie."
The New Research
In the newly published research, Berkey and colleagues from Boston's Brigham and Women's Hospital and Harvard Medical School analyzed data from a large study of obesity in adolescents in an attempt to assess the impact of milk and other dairy products on weight.
The researchers tracked the health and dietary habits of almost 13,000 children between the ages of 9 and 14 for three years starting in 1996.
In a previous analysis the researchers reported that kids who drank a lot of sugary sodas and fruit drinks gained more weight than those who didn't. Berkey tells WebMD that the decision to look at dairy products stemmed, in part, from the Dairy Council's weight loss ad campaign.
The study is published in the June issue of the Archives of Pediatric and Adolescent Medicine.
"We found that the adolescents who drank more than three servings a day of milk over a one-year period were 25% more likely to become overweight during that year than adolescents who reported drinking two to three servings a day," she says.