ø Image for milk and soda article A new reason to drink milk has been receiving attention in the news recently. Although the research is still in its early stages, some studies are finding that people who consume more calcium, particularly in the form of milk and other dairy products, tend to weigh less as they age. This is good news for milk lovers. And it may even get your teen to think about reaching for a glass of milk instead of a soda the next time he or she opens the refrigerator door.

New Research on Dairy and Weight

In the August 2004 issue of the Journal of Nutrition, researchers at the University of Hawaii reported on a study that analyzed how dairy and soda consumption affect weight and body fat among a group of teenage Asian and Caucasian girls.

The girls ranged in age from 9 to 14, and consumed about one and a half servings of dairy a day—well below the recommended three servings a day. Most of the dairy consumed was in the form of milk. Girls who drank soda averaged one large (22-ounce) bottle a day.

The authors found that some of the girls who drank milk instead of soda tended to weigh less and have lower levels of body fat, but this association was only noted in the Asian girls, who were already very thin on average. Still, the more milk they drank, the greater the effect on their weight. In contrast, girls who drank large amounts of soda tended to be heavier and have more body fat.

These findings join earlier studies that have shown similar results among other age groups. When factors like age, activity level, and total calories eaten are held steady, more and more studies are indicating that children and adults who consume more dairy products and calcium tend to have lower body weights than those in comparison groups. Keeping calcium levels high also appears to help people on diets lose weight more quickly.

More Teens Are Overweight

Is it possible that something as simple as drinking more milk can help control weight? If so, the news is particularly exciting given the number of teens who are struggling with weight. Over the last ten years, the proportion of teenagers who are overweight has increased from approximately one in ten to one in seven. Lack of exercise and poor eating habits—including drinking soda rather than milk—are two of the main culprits in this trend. Since the 1960’s, milk consumption by teens has decreased by 36%, while the consumption of soft drinks and juice has doubled. While many teens may cut back on milk because they believe it is fattening, this research may suggest that it does just the opposite.

How Does Calcium Help Regulate Weight?

Current research indicates that calcium plays an important role in regulating weight by causing shifts in fat metabolism. When mice were fed high-calorie diets, those that were also fed high levels of calcium did not gain as much weight as the others. When calories were restricted, the mice on a high calcium diet lost weight more quickly. The same pattern has also been seen in human studies. High levels of calcium seem to inhibit the creation of fat deposits in the body, and to increase the rate at which fat is burned.

Which Is More Effective: Dairy or Calcium?

It seems that consuming dairy products may be more effective for regulating weight than consuming calcium alone in the form of calcium supplements (eg, calcium in vitamin pills, calcium blocks). Components in dairy products—the proteins in milk whey in particular—may act together with calcium to impact metabolism. Or, perhaps, nondairy sources of calcium (ie, supplements) have been too small a portion of the diets of people studied to make a significant impact. The type of dairy consumed does not seem to matter, although milk is the most popular dairy product among teens.

Not a ‘Magic Bullet’

Of course, the most important factor in controlling your weight is to balance the number of calories you eat with how many you use. Researchers estimate that differences in calcium intake account for only about 3% to 10% of weight differences. The bottom line is that if you simply add more dairy or calcium to your diet, you will probably gain weight. But if you substitute a glass of low-fat milk (105 calories per eight ounces) for the soda you usually have at lunch (also approximately 105 calories for eight ounces), you may find that you gradually lose some of the extra pounds you are carrying. Increasing calcium intake seems to help people burn excess fat, particularly fat stored in the belly, while it leaves muscles intact.

More Research Needed

Although there is a growing body of research that shows a relationship between calcium intake and weight control, a few studies have found no association between the two. Some of this inconsistency may be based on how difficult it can be to accurately measure a person’s food intake. In addition, many of the studies that were used to establish the connection between dairy intake and weight were originally designed for other purposes, including studying the impact of calcium consumption on bone density, high blood pressure, and cancer. Additional research aimed specifically at measuring the impact of dairy on weight is needed in order to firmly establish the link.

In the meantime, it can’t hurt to encourage your teen to substitute a glass of milk for a soda, or a cup of yogurt for a cookie. Most teens consume much less dairy than is recommended. Increasing their milk intake should have many benefits, including, if the research is right, helping them to maintain a healthy body weight.