Can Calcium Make you Skinny?

To assess the association between calcium intake and anthropomorphic measurements such as BMI and weight, a literature search was conducted to identify human clinical trials that compared calcium intake with body mass index (BMI) and related measures such as weight and percent body fat. Forty-four studies were identified. Of those, 12 were human experimental studies that met the criteria for inclusion in the final analysis. 5, 18-23, 25-27, 32, 35 Although observational studies uniformly propose an inverse correlation between calcium intake and weight, the clinical data fail to support these reports. Most clinical trials indicate no correlation, while several report a positive correlation. In the clinical trials, calcium intakes in control groups ranged from approximately 390-1000mg/d with the median intake being approximately 683mg/d. Intakes for calcium-supplemented groups ranged from approximately 942-1256 mg/d with the median being approximately 1176mg/d. The weight change in control groups ranged from a loss of 6.4 kg to a gain of 7.2 kg over the course of the respective trials, with the median weight change being a gain of 1 kg. The weight change in calcium-supplemented groups ranged from a loss of 10.6 kg to a gain of 6.4 kg over the course of the respective trials with the median weight change being a gain of 1.6 kg. Thus, most groups experienced weight gain in response to calcium-supplementation as opposed to the expected weight loss