"Ideally, three servings of low-fat dairy products would give you the recommended amount of calcium, which is enough to suppress the fat-producing chemical," says Moore. "It's always better to get your nutrition from foods, but calcium supplements have nearly as great an effect."
In addition, the weight lost comes largely from the midsection. Fat deposits in this are a risk factor for heart disease.
"We don't know for sure exactly how the calcium causes these changes, but it's consistent across the studies," says Greg Miller, PhD, director of nutrition and science affairs for the National Dairy Council. "People who ate more dairy seem to partition energy into lean body mass rather than into fat storage."
Here are the calcium levels recommended for adults by the USDA:
Age 9 to 18: 1,300 mg
Age 19 to 50: 1,000 mg
Age 51 and over: 1,200 mg
That all sounds good, but what if you're picking out a calcium supplement? There's calcium carbonate, calcium citrate, coral calcium. There are dozens to choose from.
"Calcium carbonate or citrate doesn't matter," says Moore. "What's more important is that the supplement also contains vitamin D. That combination is what you need to maximize calcium's effects."
An interesting side note to the larger calcium story is emerging in research on soy protein and soy isoflavones. An article in the American Journal of Clinical Nutrition in December 2002 found in soy many of the same properties that have been seen in calcium. More research in soy's potential weight-loss properties is ongoing, but it is too early to say whether early findings will hold up in larger trials.