Obesity is an increasingly common health issue in developed and developing countries. There is a growing body of evidence linking high dietary calcium and dairy products with low adiposity. In the CARDIA study, Pereira et al. compared the lowest to highest quintile of calcium consumption and found the incidence of obesity reduced by 18.7% (P<0.001). Other researchers have found comparable results. Controlled trials of high calcium diets have had mixed results. In a longitudinal study of young girls, Phillips et al. found no relationship between dietary calcium or dairy products and BMI. Other studies by Zemel have found significant benefits in weight loss from diets high in calcium and in dairy. In a study of 32 obese women on an energy deficient diet, those in the high calcium and high dairy groups lost 38% and 64% more fat, and specifically more truncal fat than did women in the low calcium diet. Calcium’s modulation of adiposity appears to act through down regulating PTH and Vitamin D which have been shown to be lipogenic. Certain dangers are associated with high levels of calcium. However, most people in the US are not getting sufficient calcium, and therapeutic levels of calcium do not approach the upper limit of safety. Physicians should feel comfortable recommending that a patient increase his or her consumption of a low-fat dairy product, or use supplements to achieve the AI of calcium to reduce the risk of osteoporosis, and to enhance the weight loss achieved with a low-calorie diet and exercise.