Design of a Mediterranean exchange list diet implemented by telephone counseling

Abstract

A Greek-Mediterranean dietary pattern has two distinct aspects that differ relative to average intakes in the United States: a high intake of monounsaturated fats and a high intake of fruit and vegetables. The purpose of the study was to develop and test an exchange list Greek-Mediterranean diet that could be used in future clinical trials of breast cancer prevention. A total of 69 women, ages 25 to 59 years, were randomized to either continue their own usual diet or follow an intervention diet for 6 months during 2004 through 2005. Intervention goals were to decrease usual fat intakes by about half and to replace those fats with olive oil and other high-monounsaturated fatty acid foods; increase fruit and vegetable intakes to 7 to 9 servings/day, depending on energy intake; and consume at least one serving per day each of culinary herbs and allium vegetables. Registered dietitians provided exchange goals and individualized telephone counseling, and diets were self-selected using a Mediterranean exchange list developed specifically for this study. Changes in diet were assessed by 7-day food records. Results demonstrated that counseling using the Mediterranean exchange list was effective for large dietary changes relative to the nonintervention group. Repeated measures analysis of variance indicated a statistically significant 48% increase in dietary monounsaturated fat with no appreciable change in total fat intake, and a significant increase in fruit and vegetable intake from 4.0 to 8.6 servings/day (P < 0.05).

Figure 1

A brief version of the Modified Mediterranean Exchange List that was provided to intervention group participants. In addition to the categories shown, participants were asked to consume two to three exchanges of low-fat dairy foods, 5 to 6 oz of lean or very lean meat or other protein, and 6 to 11 carbohydrate exchanges each day, with amounts adjusted to maintain baseline energy and fat intakes. Unless otherwise indicated, one serving of fruits and vegetables was defined as 1 cup raw, 2 cups loose leafy greens, ½ cup cooked, ¼ cup dried, 1 medium vegetable or fruit, or ½ cup juice (count up to two servings/day for juice, the rest of the goal was to be met from whole foods). Starred foods were to be counted as both 1 fruit/vegetables exchange and ½ (*) or 1 (**) carbohydrate exchange. ^aMUFA=monounsaturated fatty acid. ^bPUFA=polyunsaturated fatty acid.

Figure 2

Subject recruitment and retention in the Mediterranean Eating Study.