Dietary intake in the Multiple Risk Factor Intervention Trial (MRFIT): nutrient and food group changes over 6 years

The Multiple Risk Factor Intervention Trial (MRFIT) was a randomized clinical trial in the primary prevention of coronary heart disease. Middle-aged men determined to be at high risk for coronary heart disease were randomized into either a special intervention (SI) group or a group referred to usual sources of medical care (UC). Twenty-four hour dietary recall data were used to monitor the nutrient intake of the MRFIT population and guide the nutrition education program for the SI group. The SI group of participants decreased intake of dietary cholesterol by 40% and saturated fatty acids by more than one-fourth and increased intake of polyunsaturated fatty acids by one-third. Evaluation of SI dietary intake data by food groups indicates that some dietary changes were relatively easy to implement, whereas others presented more of a challenge. Changes made with relative ease included increasing the consumption of fish and poultry, skim and low-fat milk, polyunsaturated margarines and oils, fruits, and low-fat breads and cereals and reducing the consumption of egg yolks. More difficult changes included eliminating, or even reducing, the intake of high-fat beef and pork, high-fat cheeses, high-fat crackers, snacks, and desserts, and increasing the intake of vegetarian meat alternatives.