A low-carbohydrate, Mediterranean-style diet is more effective than a typical low-fat, calorie-restricted diet for diabetes management, according to a study released Monday.

Not only did the Mediterranean diet lead to greater weight loss, it also resulted in better blood sugar control, delayed the need for blood sugar-lowering medication, and improved some heart disease risk factors, the study team found.

Mediterranean-style eating generally means plenty of fruits, vegetables and whole grains, limited amounts of red meat and processed foods, and a relatively high amount of fat from olive oil and nuts and few carbohydrates. A typical low-fat diet advises cutting down on all types of dietary fat.

Both Mediterranean and low fat diets are recommended for weight loss in overweight and obese patients with type 2 diabetes. However, there have been few direct, long-term studies comparing the two.

This led Dr. Dario Giugliano, from the Second University of Naples, Italy, and associates to randomly assign 215 type 2 diabetic patients to follow either a low carbohydrate, Mediterranean-style diet or a low-fat diet for four years.

Nutritionists and dietitians counseled both groups of patients in monthly sessions for the first year and bimonthly sessions for the next three years.

After four years, 44 percent of patients in the Mediterranean-style diet group required medication to lower their blood sugar compared to 70 percent in the low-fat diet group, the researchers report in the September 1st issue of the Annals of Internal Medicine.

After 1 year, patients in the Mediterranean diet group also experienced greater weight loss. The absolute difference in weight loss between the two groups was -2.0 kg (-4.4 lbs). The Mediterranean dieters also had trimmer waistlines.

In addition, significantly greater increases in “good” HDL-cholesterol levels and greater decreases in harmful blood fats called triglycerides were seen in the Mediterranean diet group and these heart-healthy benefits were maintained for the duration of the study.

These findings, the investigators conclude, “reinforce the message that benefits of lifestyle interventions should not be overlooked despite the drug-intensive style of medicine fueled by the current medical literature.”

SOURCE: Annals of Internal Medicine, September 1, 2009.