Weight Loss Tip: Low Glycemic Diet May Not Boost Metabolism

A recently published research revealed that 'Low Glycemic' diets may not provide important health advantage.

"The study results were very surprising," says lead author Frank M. Sacks, MD, a physician and researcher in Brigham and Women's Hospital's Channing Division of Network Medicine. "Our findings demonstrated that using glycemic index to select specific foods did not improve LDL cholesterol, HDL cholesterol, triglycerides, blood pressure or insulin resistance."

According to the study, Dr. Sacks and his team worked with 163 overweight adults, all of whom had elevated blood pressure, in a randomized, controlled trial.

Over the course of five weeks, participants were given one of four complete diets, each of which was a variation of a diet such as the DASH or the Mediterranean diet that are recommended by US national dietary guidelines.

Glycemic index measures just how quickly foods contain carbohydrates and how these raise glucose levels found in the blood stream.

"We were really surprised," said study co-director Lawrence J. Appel, M.D., M.P.H., a professor of medicine and director of the Welch Center for Prevention, Epidemiology and Clinical Research at Johns Hopkins Medicine, in a news release. "We did not detect any clear benefit of the low glycemic index diets on the major risk factors for heart disease, and we found no evidence of benefit for diabetes prevention."

"We studied diets that had a large contrast in glycemic index, while at the same time we controlled intake of total carbohydrates and other key nutrients, as well as maintained baseline body weight," says Dr. Sacks. "We found that composing a healthful diet with low-glycemic index carbohydrate containing foods rather that high-glycemic index foods did not improve insulin sensitivity, HDL or LDL cholesterol levels or systolic blood pressure."

The study was published in the Journal of the American Medical Association.