Chapter 8. Adherence to dietary recommendations in the special intervention group in the Multiple Risk Factor Intervention Trial

This chapter presents findings on adherence to the Multiple Risk Factor Intervention Trial eating pattern by special intervention participants, on the basis of measures other than the 24-h dietary recall and blood cholesterol concentrations. These additional assessments included subjective ratings by a nutritionist, used during follow-up years 1 and 2, and a food record rating that was calculated from a 3-d food record, used during years 3-6. An additional tool used during the latter part of the trial was a checklist for evaluating degree of shortfall of the participant's diet from recommendations, level of motivation toward adherence, and factors in the social environment potentially influencing dietary behavior. Subjective ratings and food record ratings indicated that ≃40-65% of participants were good or excellent adherers, with declines in these percentages over time. There were consistent strong relations between these ratings and change in serum cholesterol. Checklist evaluations gave similar overall findings, with about one-half to three-quarters of participants rated positively on infrequency of deviation from the eating pattern, motivation, and conducive environment. Several baseline traits predicted adherence. Adherence was better in older participants, in white than in black men, in nondrinkers, in those with fewer stressful life events, in those eating away from home less often, in less overweight men (although heavier participants exhibited greater changes in serum cholesterol, perhaps reflecting their poorer baseline diets), in those with higher serum cholesterol and diastolic blood pressure, and in nonsmokers.