July 29, 2005 -- A high-dairy diet may help you lose belly fat and gain muscle -- even if you don't eat less.
What's the catch? If you actually want to lose weight, you'll still have to eat less.
Those findings are the latest from Michael B. Zemel, PhD, director of the Nutrition Institute at the University of Tennessee. Zemel's earlier work showed that people on calorie-restricted diets lose more weight if they get plenty of low-fat dairy foods.
In a new two-for-one study, Zemel now extends these findings to black Americans. And he reports that obese people on high-dairy diets lose body fat and gain muscle -- resulting in zero weight loss or gain -- even if they don't eat less (and as long as they don't eat more).
"What happens when you move from a low- to a high-dairy diet without cutting calories? Well, if you just step on the scale after six months, the answer is: nothing," Zemel says. "That is disappointing. But if you look deeper, more is going on. But by just increasing dairy, your body fat comes down. These people lose nearly 5% of their body fat."
Losing Fat but Not Weight
Zemel looked at 34 obese black women and men who did not eat any more or less food during the 24-week study. Half ate three daily servings of dairy foods in place of lean meat. These people did not lose weight. But they lost nearly five pounds of body fat, gained muscle, had lower blood pressure, and lost an inch and a half around their waists.
"These people really lost a significant amount of body fat. And they gained a corresponding amount of lean mass," Zemel says. "That is remarkable."
Those on the low-dairy diet had no significant change in body fat, muscle, blood pressure, or waist size.
Of course, all of these people were still obese. Might dairy still make a difference if they ate less?
Losing Fat and Weight
"Calories do count," Zemel says. "We do not have a magic eraser. You cannot just throw milk at something and expect the pounds to melt off."
So Zemel's team put 29 obese black women and men on a calorie-restricted weight loss diet. They all decreased how much they ate by 500 calories.
They all lost weight. But those who ate lots of dairy foods lost 24.3 pounds in 24 weeks -- twice as much as those in the low-dairy group. And much more of their weight loss was fat, not muscle.
Zemel says black Americans have even more to gain from low-calorie, high-dairy diets than white Americans.
"African-Americans suffer a disproportionately high prevalence of obesity and overweight," he says. "And African-Americans consume the least calcium and the least dairy in the U.S. So this is the group at the greatest risk with the most to gain from this kind of diet."
Zemel's findings appear in the July issue of Obesity Research.
A Pitch for Exercise
Twenty-five of the 29 obese people in Zemel's diet study were black women. Losing weight is a particularly difficult problem for this population, says Carol Hogue, MD, MPH, director of the Women's and Children's Center at Emory University's Rollins School of Public Health.
Diet is important, Hogue acknowledges. But exercise is crucial, too. She argues that no discussion of weight loss can ignore the need for more exercise.
"It is very difficult for African-American women to increase their physical activity," Hogue tells WebMD. "It is a lot harder than it seems. They take care of young ones, often take care of old ones, and if they are in the work force they often care for an extended family. Adding one more thing to their life is extremely difficult to do."
Hogue is working on a project to help women increase their daily walking to 10,000 steps per day. That's about five miles of walking per day. That would take too long for most women to do at once. But by making extra walking a part of every activity, the steps add up.
A pedometer can help give you an idea of how many steps a day you take. And it can help motivate you to keep on walking.
"Research shows that that increasing one's level of physical activity really increases health whether it decreases obesity or not," Hogue says. "If a woman reduces caloric intake at the same time, she can lose weight, too."