I think its more from the CALCIUM than from the milk....
New York Times - Personal Health
June 14, 2005
All That Calcium, and Maybe Weight Control Too
By JANE E. BRODY
Could it be just a coincidence that more people have become overweight and obese as milk consumption has declined?
Might the link be that as children and adults drank less milk, they substituted the empty calories of sugar-sweetened soft drinks? Or might there be something special about milk and other dairy foods that helps people control their weight?
The dairy industry would like you to believe the latter. And it may surprise you that most of the evidence supports the industry's contention: that calcium and perhaps other substances in dairy foods can foster weight loss and especially loss of life-shortening abdominal fat.
The evidence suggests that calcium, especially in dairy foods, can help people lose pounds, if they are on a reduced-calorie diet. There is also evidence that dairy foods can keep adolescents from gaining excessive weight and perhaps help adults control middle-age spread.
Some studies that support these suggestions were financed by the dairy industry or companies that sell products like Yoplait yogurt. One prominent researcher in the field holds a patent on the claim that dairy products promote weight loss.
But most studies were done by academic researchers who were supported by government grants or other unrestricted financing. So there is no reason to distrust their findings on the basis of financing.
Clues From Studies
While studies of this kind cannot prove cause and effect, they often reveal links between two factors that suggest the need for more carefully controlled clinical trials. Indeed, quite a few studies have found a strong link between low intake of calcium, dairy products or both and excess body weight, excessive weight gain, or health conditions that can shorten life.
More than two decades ago, the first federally supported National Health and Nutrition Examination Survey found a significant association between low intake of calcium and being overweight. More recently, the Heritage Family Study, done at six major medical centers among 362 men and 462 women, found that low calcium consumption was tied to a higher percentage of body fat and especially abdominal fat, particularly in men and white women.
The relationship applies to children and adolescents as well as adults. Thus, in a study financed by the Department of Agriculture among 323 girls in Hawaii aged 9 through 14, higher intake of dairy products was associated with lower levels of body fat. The more soda the youngsters consumed, the higher their body weight.
Small wonder that American children are getting fatter. As the Hawaiian study noted, milk consumption among adolescents declined by 36 percent from 1965 to 1996, while consumption of soft drinks and noncitrus juices almost doubled.
For overweight adults, a major study indicated that dairy foods could protect against certain life-threatening complications. The four-center Cardia study followed 3,157 black and white adults, aged 18 to 30, for a decade. Among those who were overweight, low levels of dairy consumption were associated with the development of insulin resistance syndrome. This condition, also known as metabolic syndrome and syndrome X, raises a person's risk of developing Type 2 diabetes and cardiovascular disease.
These and other studies with similar findings prompted researchers doing follow-up studies to see whether a similar relationship developed among their participants over time.
Thus, the Quebec Family Study found that over a six-year period, participants who increased consumption of nonfat or low-fat milk as well as whole fruit were less likely to gain weight and body fat than those who did not make such dietary changes.
Among 99 children followed for up to 12 years in the Framingham Children's Study in Massachusetts, those who consumed the fewest servings of dairy foods a day experienced the greatest gains in body mass index, a measure of fatness.
And among 52 white children followed from age 2 months to 8 years in a study financed by Gerber Products and the Tennessee Agricultural Experiment Station, the more calcium-rich foods the children consumed, the less body fat they acquired over the years.
Dairy and Weight Loss
Now for the critical question: Can you lose weight by consuming more dairy foods? In research financed by the National Dairy Council, scientists led by Dr. Michael B. Zemel, director of the Nutrition Institute at the University of Tennessee, spent 24 weeks studying 32 obese adults who consumed 500 fewer calories than they needed to maintain their weight. (Dr. Zemel holds a patent on commercial applications of the relationship between dairy, calcium and weight control.)
The participants followed one of three diets: standard, with 400 to 500 milligrams of dietary calcium plus a placebo; high-calcium, or the standard diet with an 800-milligram calcium supplement; or high-dairy, with 1,200 to 1,300 milligrams of calcium plus a placebo.
As the researchers reported last year in the journal Obesity Research, those on the standard diet alone lost 6.4 percent of their body weight, those on the high-calcium diet lost 8.6 percent, and those on the high-dairy diet lost 10.9 percent. In addition, more abdominal fat was lost on the high-calcium diet and even more on the high-dairy diet.
In a 12-week study, supported by General Mills, the maker of Yoplait, and published this year in The International Journal of Obesity, Dr. Zemel and colleagues studied 34 healthy obese adults. Those randomly assigned to eat three servings of low-calorie yogurt a day lost significantly more weight, and a higher percentage of body fat, than those who ate only one dairy serving a day.
Before you raid the dairy case, consider these findings as well from another study supported by the National Dairy Council and published this year in The American Journal of Nutrition. Among 155 young, healthy women of normal weight, Purdue University researchers found that those who followed a high-dairy diet (1,300 to 1,400 milligrams of calcium daily) for a year ended up with the same changes in body weight and fat as those who consumed a low-dairy or medium-dairy diet.
Nonetheless, laboratory studies support the claims for weight benefits from calcium and especially dairy calcium. In a study financed by the National Institutes of Health, Dr. E. L. Melanson and colleagues at the University of Colorado Health Sciences Center demonstrated in 35 nonobese adults that a high intake of calcium was associated with higher rates of fat oxidation.
Dr. Zemel, who has studied the role of calcium in regulating fat cell metabolism, also examined the effects of dairy sources of calcium in mice prone to obesity. He reported in the journal Lipids that beyond calcium alone, dairy sources "exert markedly greater effects in attenuating weight and fat gain and accelerating fat loss."
His findings suggest that "additional bioactive compounds in dairy act synergistically with calcium" to reduce the risk of obesity.
