Relation of smoking at baseline and during trial years 1-6 to food and nutrient intakes and weight in the special intervention and usual care groups in the Multiple Risk Factor Intervention Trial

This chapter describes dietary composition according to cigarette smoking status at baseline and changes in smoking status during follow-up for men in the special intervention (SI) and usual care (UC) groups of the Multiple Risk Factor Intervention Trial. Five patterns of smoking behavior were defined: 1) sustained nonsmoking, 2) early (years 1-2 of the trial) sustained quitting, 3) late (years 3-6 of the trial) sustained quitting, 4) recidivism, and 5) continued smoking. SI men who quit smoking showed greater favorable changes in dietary lipid composition and micronutrient intake than did continued smokers, and these changes were in many instances as great as favorable changes made by nonsmokers. On the other hand, SI men who quit smoking gained an average of 3.8 lb (1.7 kg), in contrast with nonsmokers who lost an average of 6.4 lb (2.9 kg). The gain by SI quitters was, however, less than that by UC quitters, who gained 6.5 lb (3.0 kg). Moreover, despite weight gain, net change in high-density-lipoprotein (HDL) cholesterol for SI quitters was positive. With the associated decrease in low-density-lipoprotein (LDL) cholesterol, early SI quitters had the most improvement in ratio of LDL to HDL among all subgroups. Thus, unfavorable nutritional patterns of smokers put them at double jeopardy regarding cardiovascular and other chronic diseases; additionally, long-term risks can be improved not only by smoking cessation but also by achievement of healthier eating patterns.

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.