After being counseled by registered dietitians and given a list of guidelines that indicated the amount of certain foods that should be eaten each day, women demonstrated a twofold increase in fruit and vegetable intake and significantly increased their consumption of so-called “good” fats. The study was conducted by the University of Michigan Health System and published in the Journal of the American Dietetic Association.

Lead author of the study Zora Djuric, Ph.D. (research professor of Family Medicine, University of Michigan Medical School) notes that Mediterranean diets have been linked to health benefits like lower cardiovascular disease and cancer risk. Europeans who have followed traditional Mediterranean diets also have been found to live longer in recent studies. In Greece and other Mediterranean countries, diets tend to consist of high amounts of monounsaturated fats rather than the saturated fats and polyunsaturated fats that are common in the United States. Additionally, fruits and vegetables are a large part of the Mediterranean diet.

This new research represents the first time that a method has been developed to use American foods in achieving the major Mediterranean nutrient intakes. The study lasted 6 months and consisted of 69 women who were partitioned into two groups. One group received an “exchange list” of foods from registered dietitians that included foods common to a Mediterranean diet. Members of this group had dietary plans that maintained caloric and total fat intake levels that were the same as what they were consuming at the beginning of the study. They also received telephone counseling and in-person sessions at the start of the study and after three months to help them make the dietary changes.

Suggested servings, or exchanges, emphasized dark green vegetables like spinach and high-monounsaturated fats like olive oil. Other examples of exchanges include:

  • 8-10 servings every day of high monounsaturated fatty acid (MUFA) – olive or hazelnut oil, avocado and macadamia nuts
  • Limits on corn oil, margarine, tahini, pine nuts, sesame seeds and other fats that are low in MUFA
  • One or more servings each day of each of the following:
    • Dark green vegetables, such as broccoli, peas and spinach
    • Green herbs, such as basil, cilantro, peppermint and sage
    • Red vegetables, such as tomatoes, tomato sauce and salsa
    • Yellow or orange vegetables, such as carrots, red bell peppers and pumpkin
    • Other vegetables such as artichokes, cucumber, green beans and sugar snap peas
    • Other fruits, such as apples, bananas and grapes

The second group of women, called the comparison group, did not receive the exchange list or dietary counseling during the study, but continued their usual diet. After the study was completed, however, they were offered a free dietary counseling session. Similarly, if their intake of any vitamin or mineral was deficient (less than two-thirds of the recommended levels), they were provided with a list of foods that are rich in that nutrient.

The researchers found that after following the exchange plan, the women in group one were able to reach the goals of the Mediterranean diet within three months and maintain the change for the entire six-months of the study. The comparison group, however, made few dietary changes.

“That tells us that the exchange list was helpful in assisting women to make major changes in their diet, without changes in their caloric or total fat intake,” says Djuric.

The researchers conclude: “The exchange list allowed women to meet the study goals while giving them flexibility in food choices within the food exchange categories. This self-selected diet may be useful for interventions that seek to decrease cardiovascular and cancer risks, and for people seeking to follow a Mediterranean style of eating using Western foods.”

Design of a Mediterranean Exchange List Diet Implemented by Telephone Counseling
Zora Djuric, Glee Vanloon, Katherine Radakovich, Nora M. DiLaura, Lance K. Heilbrun, Ananda Sen
Journal of the American Dietetic Association (2008). 108(12): pp. 2059-2065.
doi:10.1016/j.jada.2008.09.006
Click Here to View Abstract

Written by: Peter M Crosta