Weight Loss, Diet and Fitness Program

Another observation was noted: Calcium from dairy sources was more effective at causing physiologic changes, such as lowering blood pressure. This fact dangled in front of researchers, unexplained yet intriguing.

Armed with this data, a research team at the University of Tennessee, Knoxville, designed a study to look specifically at the effect of calcium supplementation on a standard weight loss diet (500 calorie-per-day deficit) for 24 weeks. There were three different groups. All three were on the same diet that provided approximately 500 milligrams of calcium from food; one received a placebo (no extra calcium), the second received an additional 800 milligrams per day calcium as a calcium carbonate tablet. The third received an additional 800 milligrams per day calcium from dairy sources.

All the groups lost weight, as would be expected on a hypocaloric (calorie-restricted) diet. However, the degree of weight loss was significantly affected by the level and source of dietary calcium. The average amount of weight loss in each group was remarkably different. The control group lost 6.4 percent of their initial weight (equal to a 13-pound weight loss for a 200-pound person). The second group, which took 800 milligrams of calcium per day as calcium carbonate tablets, experienced a 26 percent greater weight loss, losing on average 8.6 percent (17 pounds for a 200-pound person). The final group, which consumed 800 milligrams per day from dairy sources showed the greatest response, experiencing a 70 percent greater weight loss than the control group. The dairy group lost an average of 10.9 percent of their initial weight in 24 weeks (22 pounds for a 200-pound person). Whereas the control group lost just under two inches on average from their waistlines, the dairy group lost over 3-1/2 inches.

The results of the dairy group were on the same order of magnitude as some of the more potent prescription weight loss drugs. The benefits of calcium extended beyond an acceleration of the weight loss effect of the diet. A greater percentage of the fat lost was visceral fat, the fat that collects around organs and is associated with greater risk of chronic diseases such as diabetes, heart attacks and the metabolic syndrome. With this reduction in visceral fat, subjects also demonstrated improved insulin sensitivity, meaning insulin levels were lower and glucose (sugar) from meals was shuttled into active tissue (like muscle) more quickly and efficiently. Lowering insulin levels is one of the primary goals of diets like the Zone and Atkins. Again, the degree of effect was much greater in the dairy group, compared to those who consumed their calcium as tablets.