Determined northern California dieters are helping Agricultural Research Service (ARS) nutrition researchers learn more about the role that low-fat, calcium-rich dairy foods play in healthful weight-loss regimens. The volunteers--men and women aged 22 to 45 who are nonsmokers and are 45 to 100 pounds overweight--are completing 15-week stints in which they eat varying amounts of dairy foods as part of their everyday meals and snacks.
Earlier studies, conducted elsewhere, suggest that calcium from low-fat dairy foods enhances loss of unwanted pounds--and fat. The California study, led by ARS research physiologist Marta D. Van Loan, focuses on the number of servings of dairy foods eaten per day and, as such, may shed new light on previous findings.
For example, for three weeks of the study, volunteers will eat "low-dairy" meals and snacks as is typical of their normal diets, eating only one serving of dairy foods a day, according to Van Loan. For another 12 weeks of the study, they will be assigned to either a high-dairy diet with three servings of dairy foods (milk, yogurt and cheese) or stay with the low-dairy plan of one daily serving.
One serving of dairy equals either one glass of milk, two ounces of cheese or one cup of yogurt, for example.
Van Loan is based at the agency's Western Human Nutrition Research Center, Davis, Calif. She's doing the work with ARS physiologist Sean H. Adams and chemist Nancy L. Keim, both of the nutrition center, and with co-investigators at the University of California-Davis, UC Davis Medical Center, and Iowa State University at Ames.
This ARS study is being supported in part by the National Dairy Council of Rosemont, Ill., and the Dairy Council of California, in Sacramento. Van Loan expects to have preliminary results by early 2008. The findings may help combat America's obesity epidemic. An estimated 97 million adults in this country are overweight or obese.
ARS is the U.S. Department of Agriculture's chief scientific research agency.