OHSU and Kaiser Permanente Researchers Study Health Impacts of Low-and High-Carbohydrate Diets

07/18/01    Portland, Ore.

Every year millions of Americans try low-carbohydrate and high-carbohydrate diets in an effort to lose weight. They do this even though very little is known about whether these diets are healthy or effective.

Researchers at Oregon Health & Science University and Kaiser Permanente¹s Center for Health Research (CHR) have received a $362,000 grant from the National Center for Complementary and Alternative Medicine, a branch of the National Institutes of Health, to conduct a pilot study comparing two kinds of diets. The two-year study is also supported by OHSU¹s General Clinical Research Center and by the Oregon Center for Complementary and Alternative Medicine at CHR.

"Obesity is at epidemic levels in America and is increasing," says Njeri Karanja, Ph.D., principal investigator for the study and a nutrition researcher at CHR. "Being overweight can reduce a person¹s quality of life and can have serious health consequences, including increased risk of diabetes and heart disease. So it¹s not surprising that people are experimenting with many different kinds of diets. The problem is that no one really knows how these diets impact people¹s health. Our study will look at the short-term health impacts of low- and high-carbohydrate diets. The next step will be to study people¹s health when they eat these diets over longer periods of time."

Enrollment for the clinical trial now is complete. The study will follow 24 men and women over an 18-week period. Half the participants will be randomly assigned to eat a low-carbohydrate diet similar to the Atkins diet, a popular and controversial high-fat, high-protein eating plan. The other half will be assigned to a high-carbohydrate diet similar to the DASH diet, an eating plan that is high in fruits, vegetables, grains and low-fat dairy products, and low in fats. For the first six weeks of the study both groups will be provided all the food they eat. For the following 12 weeks both groups will continue to follow their eating regimens on their own.

"We will track a number of health indicators to find out how each eating program impacts participants health," says Diane Stadler, Ph.D., R.D., co-investigator for the study and a nutrition researcher in OHSU¹s School of Medicine. "We¹ll be looking at how much weight people lose, and at changes in their body composition and energy levels. We¹ll also measure changes in bone quality and markers of heart disease, diabetes and cancer. Finally, we¹ll assess quality of life issues to find out how each diet impacts people¹s daily lives.

Kaiser Permanente¹s Center for Health Research, founded in 1964, is a not-for-profit institution that conducts research to improve the health of all people. Kaiser Permanente is a group practice health care organization serving the health care needs of about 450,000 people in northwest Oregon and southwest Washington.

OHSU includes the Schools of Dentistry, Medicine, Nursing; and the OGI School of Science and Engineering; OHSU Hospital and Doernbecher Children¹s Hospital; dozens of primary care and specialty clinics; multiple research institutes and several public service and outreach units.

Particulars:
Diane Stadler, Ph.D., adjunct research associate professor of medicine (endocrinology, diabetes and clinical nutrition), OHSU School of Medicine

Njeri Karanja, Ph.D., investigator, Kaiser Center for Health Research and adjunct research associate professor of medicine (endocrinology, diabetes and clinical nutrition), OHSU School of Medicine.

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