Increasing the total calcium intake, in the form of calcium supplementation, may be beneficial for weight maintenance, especially in women during midlife.
However, this does not mean that calcium can be recommended as a weight maintenance aid and randomised clinical trials are necessary to determine whether calcium really is responsible for limiting weight gain.
There is some evidence that calcium can help people stay slimmer but it is not conclusive. The explanation for how calcium might exert such effects are studies showing that low calcium intake boosts the amount of calcium contained within cells, which in turn switches on genes involved in fat formation, while inhibiting fat breakdown.
Researchers from the Fred Hutchinson Cancer Research Center in Seattle, USA, looked at weight gain and calcium intake over an 8- to 12-year period in 10,591 men and women aged 53 to 57 years. While calcium intake had no relationship with weight gain in men, the women who consumed more than 500 milligrams of calcium in the form of supplements gained 5 kilograms over 10 years, compared to 7 kilograms for those who didn’t take calcium supplements.
Although more evidence from randomised clinical trials is needed before calcium supplements can be recommended specifically for weight loss, this study suggests that calcium supplements taken for other reasons (e.g., prevention of osteoporosis) may have a small beneficial influence on reducing weight gain, particularly among women approaching midlife.