Prevent Diabetes without Losing Weight

This website is all about translating Mediterranean Diet principles for the American kitchen. Hundreds upon hundreds of well-designed studies document the positive effects of a Mediterranean-style diet upon blood pressure, cholesterol scores, and conditions both major and (comparatively) minor as heart disease, cancer, Alzheimer's Disease, pneumonia, and osteoporosis. We also know that a Mediterranean diet can help prevent diabetes.

When the media discuss diabetes prevention, there's often a primary focus on weight loss. While it's true that those with excess body weight are at a demonstrably greater risk of developing diabetes, it's ruinously shortsighted to assume that weight loss alone will solve the problem: excess body weight is not the only risk factor.

In Spain, one of the original Mediterranean countries, an recent study known as PREDIMED (Prevención con Dieta Mediterránea; translation: Prevention with the Mediterranean Diet) has shown that a Mediterranean style diet can reduce the risk of diabetes without a single lost pound (Ann Int Med 2014;160:1-10).

In October of 2003, over 3,000 men and women over the age of 55 were recruited to participate in a feeding study. None of the participants had diabetes at the start of the study, but they all had three or more risk factors for heart disease, including current smoking, high blood pressure, poor cholesterol scores, excess body weight, or a family history of heart disease.

The participants were randomly assigned to one of three groups:

• a control group, who received dietary counseling on a low-fat diet;
• an Extra Virgin Olive Oil (EVOO) group, who received counseling on following a Mediterranean-style diet along with a daily allotment of 50 milliliters (about 1.5 ounces) of EVOO; and
• A Mixed Nuts (MN) group, who received the same Mediterranean diet counseling and a daily allotment of 30 grams per day of mixed nuts (walnuts, almonds, and hazelnuts).

All of the participants were weighed and had their blood pressure and cholesterol and glucose levels tested at the start of the study. They also filled out a dietary questionnaire designed to assess their current level of adherence to a Mediterranean style diet, which was repeated on a yearly basis throughout the study.

None of the participants was advised to restrict their caloric intake (to lose weight), nor were they instructed to change their physical activity.

The results are remarkable: after taking into account such variables as age, Body Mass Index, and sex, those in the EVOO group were 40% less likely to develop diabetes than those in the control group. Those in the MN group were 18% less likely. Taken together, the Mediterranean diet groups were 30% less likely to develop diabetes than those on a low-fat diet.

What this means for you

The participants in this study reduced their risk of diabetes without trying to lose a single pound. As the authors put it, "Changes in body weight, waist circumference, and physical activity were minor and did not differ by study group." Interestingly, of the 14 points in the dietary questionnaire that related to Mediterranean Diet, both Mediterranean diet groups improved their score in 9 of the points. How can you improve your Mediterranean Diet score? You can learn more about the principles of the Mediterranean Diet on the Web site.

First posted: January 8, 2014
Updated: December 18, 2019
Updated: March 26, 2024