Oct. 8, 2008 -- Eating calcium-rich foods may do a body good, but calcium
probably won't help you lose weight, new research
In a rigorously designed study to examine the issue, investigators found no
evidence that calcium supplementation influenced energy expenditure or
fat-burning in overweight people whose regular
were deficient in the mineral.
Widely publicized animal and human studies that did suggest a role for
calcium in weight loss led to a multimillion dollar ad campaign promoting
three servings of dairy products a day with slogans like "Milk your diet.
The new study was conducted in an effort to confirm or disprove the findings
in these earlier studies, metabolic physiologist Hilary Green, PhD, of Nestle,
"There was no evidence in this latest research to suggest that calcium
helps people burn more fat through the mechanisms that were tested," she
Calcium and Weight Loss
The 20-week study, conducted by researchers from Switzerland's University of
Lausanne and the Nestle Research Center, included 10 overweight or obese people
identified before recruitment whose regular diets were low in calcium.
Study participants were randomly assigned to be given either placebo or 800
milligrams of dairy calcium daily for two five-week periods, separated by a
10-week washout phase.
Four weeks into the supplementation phases of the study, researchers
performed a battery of tests designed to examine the impact of calcium on fat
The tests revealed no differences between the people taking the placebo and
the calcium in any of these measures, including resting energy expenditure, fat
oxidation, and plasma-free fatty acid concentrations.
In addition, expression of seven key metabolic genes in biopsied fat tissue
was not affected by calcium supplementation.
In an accompanying editorial, University of Copenhagen nutrition researcher
Arne Astrup, MD, writes that the study makes a strong case against the
hypothesis that calcium-controlled pathways in fat tissue help regulate body
But he concludes that there is still good evidence indicating a role for
dietary calcium in weight regulation.
The study and editorial appear in the October issue of the American
Journal of Clinical Nutrition.
Dairy Industry Weighs In
Greg Miller, PhD, who is a spokesman for the National Dairy Council, tells
WebMD that the study addressed just one of several theories about calcium and
"There is a good body of evidence that supports a relationship between
calcium intake, dairy intake, and weight and body fat regulation," he says.
"What we are trying to understand now is what mechanism or mechanisms are
involved and under what conditions do they have an effect."
He points out that the study did not address the role of calcium and protein-rich foods in
controlling appetite. New research also suggests that calcium may bind fat and
decrease its absorption from the intestinal tract.
But the Dairy Council's advertising no longer makes the claim that eating
dairy foods leads to weight loss. Miller confirms that the 3-a-day campaign and
other promotional ads now focus on the role of dairy foods in maintaining a
Early last year, the Federal Trade Commission and the FDA expressed concern
about the weight loss claims made in the ads, but Miller says the decision to
shift the focus from weight loss to weight regulation was entirely
"Our marketing outreach told us that consumers were tired of hearing
about dieting and our current marketing reflects that," he says.