Researchers in Sao Paulo, Brazil, analyzed the diets and lifestyles of about 1,500 men and women, aged 20 to 59, to determine if calcium affects weight. Nearly 30 percent of participants were overweight and another 13 percent were obese. For the overall group, the average amount of calcium in the diet was about 450 mg per day. Those who consumed the least calcium, less than 265 mg per day, were 24 percent more likely to be overweight compared to those who consumed the most calcium, about 600 mg per day. Study authors believe that calcium may bind to fatty acids in the intestine and keep these fats from absorbing into the bloodstream, helping maintain healthy weight. The doctors noted that those who consumed higher levels of calcium tended to be non-smoking women with normal weight who were physically active and who had higher levels of education compared to those who consumed less calcium.