High-calcium, low-calorie diets help obese mice lose weight at rates double those of mice given low levels of calcium. Researchers believe high levels of dietary calcium may suppress hormones that help us 'hold on' to stored fat. For any given level of energy balance -- of calorie intake and physical activity -- dietary calcium helps determine whether calories go to storage in the form of fat, or get burned.
The investigators were first tipped off to a potential link between calcium and fat metabolism in studies conducted years ago in obese men. When the men were placed on high-calcium diets they lost significant amounts of body fat, -- even though their calorie intake remained the same. Studies in mice suggested that low-calcium diets help stimulate hormones that push dietary calcium into fat cells. These hormones also appear to 'switch on' fat-storing and fat-preserving mechanisms within fat cells. High-calcium diets seem to have the opposite effect -- suppressing these weight-gain hormones so that the mice stay thin.
But would high-calcium diets help already obese mice lose weight? In their latest round of research, researchers provided overweight mice with one of five diets. One group of mice stayed on the same high-calorie, low-calcium regimens that made them fat to begin with. The other four groups were placed on 30% reduced-calorie diets with varying levels of calcium intake, either from supplements (calcium carbonate) or dairy (dry skim milk powder).
Animals placed on low-cal, low-calcium diets did lose a little weight -- about 11% of total body weight and 8% of total body fat. But obese mice placed on the high-calcium, low-cal diets lost roughly a fifth of their body weight and 42% of their body fat over the next 6 weeks. And mice who got their calcium from dairy lost even more -- a quarter of their body weight and 60% of their body fat.
Clinical trials are now underway, and results in humans should become available within a year. It's not clear why calcium from dairy might stimulate fat loss any more efficiently than supplemental calcium carbonate. Calcium is also found in produce such as collards, turnip greens, rhubarb, broccoli and kale.
Experimental Biology 2000 Conference San Diego April 17, 2000
The basics of losing weight are grain restrictions as I mention in my diet program. Additionally, reviewing the articles on exercise will also outline the importance of this factor in losing weight. (one, two)