More dairy foods in the diet may boost fat burning

Milk is for sale at a Sam's Club in Fayetteville, Arkansas June 5, 2008.

NEW YORK (Reuters Health) - Eating plenty of dairy foods may help people who are trying to maintain their weight to burn more fat and eat more calories without putting on excess pounds, according to new research published in the journal Nutrition & Metabolism.

The study, funded by the National Dairy Council, didn't find that eating the recommended three servings of dairy food each day made any difference in helping people keep off the weight that they had lost, but it did show that they were able to consume more calories without gaining weight compared with people who consumed less than one dairy serving daily.

Being able to eat more calories may make it easier for people to stick to a weight-maintenance diet, suggest lead researcher Dr. Michael B. Zemel of the University of Tennessee in Knoxville and his colleagues.

Zemel has received grants from the National Dairy Council, and also holds patents on the use of calcium in weight management.

Previous studies have shown that high calcium diets can reduce weight gain and fat accumulation in overfed rats, and may help the animals burn off fat and pounds when their diet is restricted, Zemel and his team note. Some studies in humans have also found that calcium promotes fat loss, possibly by making it harder for the body to hold on to fat cells.

However, no studies in humans have looked at whether calcium and dairy foods help people maintain their weight. To investigate, researchers had 338 obese men and women cut their calorie intake for 3 months.

Study participants who lost at least 10 percent of their weight or 10 kilograms were then randomly assigned to eat less than a single serving of dairy daily or more than three servings a day for the next 6 months.

During the weight maintenance portion of the study, weight and body composition were similar in both groups. However, people in the high-dairy group were eating 9 percent fewer calories than they were at the study's outset, compared with 22 percent fewer calories for the low-dairy group.

"This suggests that diets with recommended levels of dairy may be higher in energy content (calories) while producing similar effects on body weight and fat as diets low in dairy," the researchers write.

Men and women in the recommended dairy group also had lower blood levels of calcitriol, the active form of vitamin D, which blocks the breakdown and oxidation of fat cells.

They conclude that people who what to maintain their weight loss, dairy products can be added to their diet without contributing to weight gain.

SOURCE: Nutrition & Metabolism, online October 24, 2008.