The participants were obese women, who were examined over the course of 15 weeks. They were placed on a low-calorie, low-calcium diet with an average calcium intake of 600 milligrams. (The recommended daily allowance of calcium is 1,000 mg.) The women were split into two groups, one of which took a daily placebo and the other of which took two tablets totaling 1,200 mg of calcium a day. The high-calcium group lost an average of almost 6 kilograms (13 pounds) over the 15-week period, while the placebo group lost just 1 kg (2 pounds).
“Our hypothesis is that the brain can detect the lack of calcium and seeks to compensate by spurring food intake, which obviously works against the goals of any weight-loss program,” said Tremblay, a professor at Université Laval. “Sufficient calcium intake seems to stifle the desire to eat more.”
Therefore, Tremblay declared, for people to lose weight successfully, they should start by ensuring they take enough calcium per day. He said more than 50 percent of obese women patients at his research clinic fail to consume the recommended daily amount.
Tremblay’s previous work on calcium and obesity showed in 2003 that women on low-calcium diets had greater body fat, larger waistlines and more bad cholesterol than those who ingested moderate or large amounts of the mineral. Another study, six years in length, revealed that as people reduced their intake of dairy products, their body fat and waistlines increased. A third investigation, in 2007, found a link between dietary calcium and lower cardiovascular risk.