In a new study led by the University of Michigan Health System, women more than doubled their fruit and vegetable intakes and dramatically increased their consumption of "good" fats when they were counseled by registered dietitians and provided with a list of guidelines on the amount of certain foods they should eat each day.

The six-month study of 69 women divided the participants into two groups. In one group, registered dietitians used an "exchange list" of foods that are common in a Mediterranean diet to make a plan for each participant. The new plan maintained the caloric and total fat intakes that the participants consumed at the beginning of the study.

The list included suggested servings, or exchanges, of several categories of foods - such as dark green vegetables, such as spinach, or high-monounsaturated fats, such olive oil. The dietitians also provided counseling on the telephone to help the participants to make the dietary changes, as well as in-person sessions at the start of the study and three months later.

Women in the comparison group continued their usual diet and did not receive any dietary counseling, though they were offered one free dietary counseling session after they completed their part in the study. If their intake of any vitamin or mineral was less than two-thirds of the recommended levels, they were given a list of foods that are rich in that nutrient. They also were given the National Cancer Institute's "Action Guide to Healthy Eating."

Researchers found that the group that followed the exchange-list plan reached the goals of the Mediterranean diet within three months, and maintained the change for the six-month duration of the study. But the comparison group that did not use the exchange list or receive dietary counseling made few dietary changes…