Dairy Calcium Aids Weight Loss: New Research
Hines F. Boyd, PhD(1)Make your weight-loss diet easier with dairy products. You will lose more quickly if your diet includes plenty of milk, yogurt, and cheese. Three to four servings per day of low-fat or skim milk, fat-free yogurt, or cheese will give you the calcium you need and won’t add excessive calories to your diet.
Keeping 1,200 to 1,600 milligrams of calcium, mostly from dairy products, in the diet will not only take off the pounds more quickly, but it will take those pounds off in the right place: around the waist. Calcium supplements don’t promote weight loss as well as dairy products. Those are the conclusions of a large body of emerging research on the effects of calcium on weight loss.
The research began by accident in 1988 at the University of Tennessee where Dr. Michael Zemel was investigating the possibility that diets rich in calcium could reduce high blood pressure. He increased the dietary calcium of a group of obese African-American males by giving them two cups of yogurt per day. Not only did their blood pressures come down, but at the end of the one year study, these men had unexpectedly lost an average of 11 pounds, yet they consumed the same calories as the control group who did not lose weight.
Dr. Zemel initially was skeptical about the weight-loss results. However, more research showed that he might be onto something. Dr. Zemel and his associates analyzed the database created by a six-year survey on the health and nutrition status of 33,994 diverse individuals. He found that body fat was significantly lower in people who consumed more calcium, with all other factors being equal. In fact, people with high levels of calcium in their diet had dramatically reduced levels of obesity.
Dr. Zemel also set up a study in which obese mice were placed on a restricted diet but with varying levels and kinds of calcium. While the low-calcium diet resulted in an 11 percent loss in body weight and an 8 percent loss in body fat, the rats on the high- calcium diet lost 20 percent of their body weight and 42 percent of their body fat. When the calcium came from dairy products the results were even more striking -- these rats lost 25 percent of their body weight and 60 percent of their body fat.
Meanwhile, at Purdue University, Dr. Dorothy Teegarden and Dr. Connie Weaver were studying bone health in young women. Like Dr. Zemel, they also noticed that the calcium-rich diets in their study seemed to affect weight. The women who consumed a lot of milk, cheese, and yogurt either maintained or lost weight, while those who shunned dairy products gained weight.
As word of these studies began to spread in the scientific community, more research commenced. At Creighton University, noted osteoporosis researcher Dr. Robert Heaney re-analyzed some of his studies that included data on calcium intake and weight. He noted that, age notwithstanding, the women with higher calcium intake tended to weigh less. In fact, each 300-milligram increase in daily calcium -- equal to about six ounces of yogurt -- lowered average body weight approximately six pounds. Dr. Heaney also analyzed data from clinical and epidemiological studies and made the startling prediction that increasing the national individual average calcium intake to 1,000 milligrams per day could reduce obesity in the United States by 60 percent to 80 percent.
Until recently, most of the studies on calcium and weight loss involved data from mice, cell cultures, or epidemiological studies. So Dr. Zemel performed a 24-week clinical study with 32 overweight adults who were placed on a 500-calorie deficit diet. In other words, they received 500 calories per day less than required for normal body maintenance. A control (low-calcium) group received a calcium supplement of 400-500 mg/day. A second (high-calcium) group received an additional 800 mg/day calcium supplement. A third (dairy calcium) group received 1,200-1,300 mg/day calcium from dairy products.
The results from Dr. Zemel’s clinical studies were impressive. The control or low-calcium patients lost 6.4 percent of their body weight. The high-calcium supplement group did a little better, losing 7.7 percent of their body weight. The diary calcium group, however, lost 10.9 percent of their weight -- or 70 percent more than the low-calcium control group. Two-thirds of the dairy group’s weight loss was in the abdominal region, while only 20 percent of the low-calcium group’s fat loss was around their waists.
Dr. Zemel and his associates are also doing studies to learn how calcium operates at the molecular level to control fat metabolism. Their research suggests that a hormone called calcitrol can act as a “switch” for fat metabolism and is signaled by calcium levels in the blood. When calcium levels are too low, calcitrol tells the body that it needs to hold onto its fat. In other words, with low calcium, the calcitrol regulatory mechanism thinks the body is being starved and that it needs to slow down fat metabolism while protecting its fat stores.
Having too much unsuppressed calcitrol might explain why dieters frequently have trouble losing weight, especially if their weight-loss diets do not include enough calcium. Adequate levels of calcium seem to reduce calcitrol activity, thus reducing fat storage while allowing the body to burn fat more quickly.
Dr. Zemel and his colleagues are also investigating the reasons that dairy calcium is more effective than calcium supplements in promoting weight loss. They believe that diary products have bioactive components that enhance the effects of calcium in the body. Though they have not identified these components yet, they have evidence that these bioactive ingredients may reside in the whey portion of dairy products.
DON’T MAKE THIS DIETING MISTAKE
So what does this new research mean for people who diet? It means you will probably lose more weight if you include dairy products in your weight-loss diet. Unfortunately, because people fear the fat found in some dairy products, diary is frequently eliminated from weight-loss diets -- a big dieting mistake.
A successful weight-loss diet should include 1,200 to 1,600 milligrams of calcium per day, with at least 1,000 milligrams coming from dairy sources. Since your body cannot absorb more than about 500 milligrams of calcium at a time, this means eating three to four servings per day of dairy products such as milk, cheese or yogurt.
The accompanying table lists several excellent dairy food choices that
are rich in calcium but relatively low in calories. If you’re on
a high-protein diet, the table includes information to help with that,
too. The items are ranked by their calcium-to-calorie ratios. All are
very calcium-dense, meaning you get a lot of calcium for your calories
with these six dairy foods.
Select several of these products and work them into your diet -- with
meals or as snacks -- to get your three to four servings. Also, check
the product nutrition labels since formulations differ, especially for
flavored yogurts and low-fat cheeses.
Whatever you select, items from this list won’t add many calories and you’ll still be able to include other good food choices in your diet. And, most important, they’ll help speed up your weight loss.
One final caution: the research shows how calcium helps people who are dieting lose weight faster and may help keep the weight off. Calcium probably won’t help you lose weight if you don’t reduce your overall calorie intake -- you can’t solve a serious overweight problem simply by eating dairy products. Include plenty of fruits and vegetables, exercise and other healthy lifestyle practices as part of your overall weight-loss program.
Table 1. Dairy Diet Boosters |
||||||
| Calcium Dense Food Item | Serving Size |
Calcium (Mg) |
Calories (kcal) |
Mg Ca perCal |
Carbs (g) |
Protein (g) |
| Cheese, Swiss, lowfat | 2 oz | 540 | 100 | 5.4 | 2 | 16 |
| Yogurt, fat free, plain | 8 oz. | 485 | 135 | 3.6 | 19 | 14 |
| Milk, fat free | 10 oz. | 375 | 105 | 3.6 | 14 | 10 |
| Yogurt, fat free, fruit flavored, low-cal sweetner |
8 oz. | 375 | 130 | 2.9 | 20 | 11 |
| Milk, 2% | 10 oz. | 340 | 150 | 2.3 | 13 | 10 |
| Cheese, Swiss | 2 oz. | 450 | 215 | 2.1 | 3 | 15 |
| Cheese, Cheddar | 2 oz. | 410 | 230 | 1.8 | 1 | 14 |
| (1)Dr. Boyd is former Director of the Division of Dairy Industry, Florida Department of Agriculture and Consumer Services | ||||||
