You've seen the ads touting dairy products as a weight-loss wonder. You've also heard it's an express ticket to fat-land. Which leaves you hanging over the cheese tray, toothpick in hand, wondering whether you're supposed to eat up or steer clear. We took a look at the latest research, questioned the most in-the-know experts, and found some answers to your dairy dilemmas.
How well documented is the role of dairy in weight loss? Are people getting excited over nothing?
In the past 3 years researchers have published 60-plus studies on dairy and weight loss, and many support the idea that dairy may be a fat-burning elixir. "The data that's been coming out is very interesting, very provocative, highly suggestive," says Pamela Peeke, M.D., assistant professor of medicine at the University of Maryland and author of Body for Life, for Women. The research into dairy as one of the ways to lose weight is still new, so there's no overwhelming consensus yet. Most scientists are clamoring for more data before they come to any definitive conclusions.
What have these studies found about the connection between weight loss and dairy products?
The news that's starting to come out is pretty cool. In some cases research shows that dairy-fueled weight loss leads to a more toned physique. Ordinarily, when people lose weight they lose some muscle along with the fat. "What we've shown [in our studies] is that on dairy-rich diets, more of the weight you lose is fat and less is muscle," says Michael Zemel, Ph.D., professor of nutrition and medicine at the University of Tennessee. He's also the foremost proponent of the dairy/weight loss connection. Scientists recognize that people who already have lots of dairy in their diet often weigh less than those who don't. "Most of the epidemiological studies, where they take a cross section of people and study them, support a relationship between calcium, dairy products, and lower body-fat mass," says Dorothy Teegarden, Ph.D., professor of nutrition at Purdue University in West Lafayette, Indiana. Studies in which people added dairy to their diet are less conclusive, but some have had promising results. Dr. Teegarden's research team recently found that women who ate three to four servings of dairy a day burned more fat and calories — potentially 10 pounds of fat a year — than women who ate only one to two servings. On the other hand, a University of Vermont study indicated that adding more dairy to a low-calorie diet didn't help dieters lose weight any faster than those who just cut calories.
But aren't most dairy products full of fat? Why are people who consume more dairy thinner?
The main reason is that dairy is full of calcium. It appears that increasing calcium helps release fat-burning hormones and that other compounds in dairy help you hold on to muscle tissue often sacrificed during a weight-loss program. Other research indicates that when your body has too little calcium, the chemicals released to help maintain regular levels slow fat burning. "So on a low-calcium diet you're breaking down less fat, and you're making more fat," Dr. Zemel says. "The result is bigger, fatter fat cells, and lots of big, fat fat cells makes for big, fat us."
Does calcium work that way for everyone?
No. The best weight-loss results were seen in participants who were initially consuming only about one serving of dairy a day — about 500 milligrams of calcium — and then at least tripled their intake.
Will it work for me?
Probably, considering that only one out of six women gets the dairy she needs (about three servings a day). So there's an 83 percent chance that you're not consuming enough milk, cheese, and yogurt — and eating more of it is likely to give you weight-loss benefits.
While I'm waiting for the final verdict, can't I just take a calcium supplement?
No (although we won't discourage it for bone-building purposes). It's not just calcium that gives dairy its supposed slimming power. According to researchers, proteins in dairy may work with calcium to enhance fat loss. Researchers are in the process of identifying these dairy proteins, but one is the angiotensin-converting enzyme (ACE) inhibitor, which not only keeps blood pressure down but may also prevent fat storage and weight gain.
So, eat more cheese and lose weight? I'm in.
Not so fast. Calories still (and always will) count. When you add dairy calories to your diet, you have to trim calories somewhere else. Studies have shown that you have the best chance of weight loss when you combine high dairy consumption with a reduced-calorie diet (so don't even think about getting your calcium the Hagen-Dazs way). In the studies that link dairy and weight loss, the study participants also cut 500 calories a day from their diets, the standard deficit for weight-loss plans. "In the absence of caloric restriction, you don't lose weight when you switch to [a diet] high [in] dairy," Dr. Zemel says.
Won't cutting out 500 calories a day lead me to lose weight anyway, whether I'm eating dairy or not?
What are you, a research scientist? You're right — which is why most experts aren't ready to come out and wholeheartedly endorse dairy as a weight-loss tonic. Dairy may help you lose more weight, or lose more fat, or lose weight faster, but (all together now) we still need more research before we know for sure.
So what's the bottom line?
Whether or not dairy is the fat burner you've been dreaming of, chances are you still aren't getting the servings you need to stay healthy. Even if this dairy craze turns out to be just that, the benefits for your bones of getting calcium through milk, cheese, and yogurt are undeniable. "If [using dairy to lose weight] is the pivot point to a healthier lifestyle, then rah-rah, whatever it takes," Dr. Peeke says. In the end, this so-called "dairy diet" touts the same dietary guidelines that have been in place for years for optimal bone health — three servings of dairy daily. So feel free to drink straight from the carton.