Psychosocial correlates of healthful diets among male auto workers

A better understanding of factors associated with healthful eating practices can improve the design and evaluation of dietary intervention programs. Up to now, little information has been available about these factors in high-risk but healthy populations. This article presents findings of a study of psychosocial factors, including stage of change, and their relationship to patterns of consumption of dietary fat, fiber, and fruits and vegetables in a population of males at increased risk of colorectal cancer. Data are from the baseline survey for the Next Step Trial, a randomized, controlled trial of worksite nutrition and colorectal cancer screening promotion interventions. The respondents (n = 2764) were actively employed or retired auto workers at increased colorectal cancer risk. The psychosocial constructs measured were predisposing factors (benefits, motivation, knowledge; eight items; Cronbach alpha = 0.50), enabling factors (barriers, norms, social support; six items; Cronbach alpha = 0.55), and stages of change for adopting diets lower in fat and higher in fiber/fruits and vegetables. The measures of diet, assessed with a food frequency questionnaire, were intakes of fat, fiber, and servings of fruits and vegetables. There were strong and statistically significant positive associations between both predisposing and enabling scale scores and stages of change for fat and fiber. The percentage of respondents in maintenance stage ranged from 4-80% for fat and 11-81% for fiber, across low to high predisposing scale scores; for enabling scale scores, ranges were 11-71% for fat and 22-81% for fiber. Stage of change was associated with fat, fiber, and fruit and vegetable intake in a stepwise manner, with the greatest change observed between action and maintenance. Correlations with dietary outcomes were significantly greater for predisposing factors (r = -0.30 for fat and 0.36 for fiber) than for enabling factors (r = -0.23 for fat and 0.28 for fiber). Multiple regression models, which included the predisposing and enabling factor scales, stage of change, and covariates related to diet, explained a total of between 16 and 27% of the variance in diet. Predisposing and enabling factors are significantly associated with of stage of change and current diet in this high-risk sample of male auto workers. Stage of change is the strongest correlate examined and seems to serve as a mediating factor for dietary change. Results from the Next Step Trial will provide additional data on whether and how health promotion interventions influence these factors, and whether such changes are associated with dietary change.