Change and 1-year maintenance of nutrient and food group intakes at a 12-week worksite dietary intervention trial for men at high risk of coronary heart disease

Abstract

We examined how dietary habits (i.e., intake of nutrients and food groups) were changed by intervention and how once adopted diets were maintained thereafter using the data of a 12-wk worksite dietary intervention trial for men at high risk of coronary heart disease (i.e., hypercholesterolemia, hyperglycemia, and/or overweight). Dietary habits were assessed pre- and post-intervention and 1 y follow-up points using a self-administered diet history questionnaire. The intervention method was a brief individual counseling based on the results of a pre-intervention assessment and a weekly distribution of newsletters. At the pre- and post-intervention points, a control group selected from the workers was used for comparison. The Keys score, and the changes in intake of saturated fatty acids (SFA), monounsaturated fatty acid, total fat, and cholesterol (the decrease), as well as dietary fiber, potassium, calcium, and iron (the increase) were significantly different between the intervention (n = 63) and control (n = 123) groups (p < 0.05). The changes were almost maintained with little recidivism at the 1 y follow-up point in the intervention group (i.e., for the decrease in SFA and Keys score, p < 0.001). The decrease in serum cholesterol level expected from the change in Keys score and body weight, taking possible regression to the mean into consideration, was almost identical to and slightly greater than (18%) those observed at the post-intervention and 1 y follow-up points, respectively. The results suggest that the favorable changes in dietary habits adopted during an intervention period were almost maintained for the subsequent 1 y period.