Increased dairy product or calcium intake: is body weight or composition affected in humans?

To assess the possible impact of increased intakes of dairy products or calcium on body weight or composition, a MEDLINE search was conducted to identify randomized trials of supplementation with calcium or dairy products. Nine studies of dairy product supplementation were located: In seven, no significant differences in the change in body weight or composition were detected between treatment and control groups. However, two studies conducted in older adults observed significantly greater weight gain in the dairy product groups. The interpretation of these findings is complicated by the inability to accurately determine the extent of dietary compensation for the increment in energy intake provided by the added dairy products. This is not an issue in the interpretation of studies of calcium supplementation, of which 17 were identified. Only one study found greater weight loss in the supplemented group; in the remaining studies, changes in body weight and/or body fat were strikingly similar between groups. In conclusion, the data available from randomized trials of dairy product or calcium supplementation provide little support for an effect in reducing body weight or fat mass. However, the studies reviewed were not specifically designed or powered to address this issue; such studies are required.