Dr. Zemel did publish a small study showing obese subjects instructed to consume more low-fat and nonfat dairy products lost more weight than those instructed to follow a more conventional low-calcium (about 400-500 mg/day) weight loss diet.1 Those on the low-calcium diet either took a placebo or a calcium supplement (800 mg/day).

? The group consuming the low-fat dairy products lost 70% more weight over 6 months and 64% more body fat than the group on the low-calcium diet (plus placebo).? Those who followed the low-calcium diet but took the calcium supplement lost 26% more body weight plus 38% more body fat than the group with a placebo. This suggests that a low calcium intake may make losing body fat more difficult.Because the researchers did not measure calorie intake, it is hard to say for sure why subjects lost more weight with the low-fat dairy and calcium supplements. A low calcium intake does increase calcitrol (active form of vitamin D) in the blood, and this increases calcium influx in fat cells, which appears to favor fat accumulation.Weight loss in older women does tend to promote calcium loss from the bones, so it makes sense to include a moderate amount of calcium-rich foods for them. But men might not want to follow the same advice just yet. Data from the large Physicians? Health Study found that men who consumed more dairy products and calcium were more likely to develop prostate cancer than those who consumed less.2Bottom Line: The use of moderate amounts of nonfat dairy products as part of a weight-control diet seems reasonable, but this does not mean fatty dairy products with added sugar are a healthy addition to a weight-loss diet.By James Kenney, PhD, RD, LD, FACN.1. Obesity Research 2004;12:582-902. Am J Clin Nutr 2001;74:549-54