Patterns of dietary behavior associated with selecting diets low in fat: reliability and validity of a behavioral approach to dietary assessment.

This report describes the development and evaluation of a behavioral measure of dietary patterns related to selecting low-fat diets. An 18-item questionnaire, based on an anthropological theory of dietary change, was developed to assess four relevant dimensions of dietary behavior: (a) excluding high-fat ingredients and preparation techniques, (b) modifying high-fat foods, (c) substituting specially manufactured low-fat foods for their higher-fat counterparts, and (d) replacing high-fat foods with low-fat alternatives. In this study, 99 women completed the diet behavior questionnaire twice and, to characterize precisely their dietary fat intake, also completed two 4-day food records and a food frequency questionnaire. Participants were aged 45 to 59 years and were selected to have a wide range of fat intakes (19.4% to 49.4% of calories from fat). Confirmatory factor analysis identified five scales that corresponded to those hypothesized, except for exclusion, which split into avoiding meat and avoiding fat as a seasoning. The scales had high test-retest and internal consistency reliabilities, and correlations with percent of calories from fat ranged from 0.34 to 0.57 (p less than .01). The correlation of the sum of the five scales (18 items) with percent of calories from fat was 0.68 (p less than .001) and, in multiple regression models, the multiple R2 using all factors to predict percent of calories from fat was 0.47. Overall, these findings supported the validity of the theoretical model of dietary patterns related to selecting diets low in fat. We conclude that a standardized, behavioral approach to measuring fat-related dietary behavior may be useful for designing and evaluating nutrition intervention programs.