Evaluation of validity of items for a food behavior checklist

Objectives To evaluate the validity of food behavior items, using a biologi cal measure (serum carotenoids) as the criterion for validity of fruit and vegetable intake, and the results from multiple 24-hour recalls to test con vergent validity with nutrient intake. Design Participants responded to 39 food-behavior questions and later compl eted three 1-day dietary recalls. Serum carotenoid levels were determined f or a 59% randomly selected subsample. Subjects/setting A convenience sample of 100 English-speaking, low-income w omen participating in a Food Stamp Nutrition Education Program in 8 Califor nia counties. Statistical analyses Spearman correlation coefficients were calculated betw een responses to the food behavior items and (a) serum carotenoid levels an d (b) mean nutrient intakes from the 24-hour recalls. Cronbach's coefficien t a was determined for items within broad food behavior topics. Results Responses to 10 food behavior items were significantly correlated w ith serum carotenoid levels (correlations greater than 0.45 were found for choosing low-fat foods and a self-evaluation of overall dietary quality). A n additional 12 items showed hypothesized associations with the 24-hour rec all data (with a maximum correlation 0.50 for number of eggs per week and d ietary cholesterol). Cronbach's coefficient a ranged from 0.28 (for 5 fat a nd cholesterol items) to 0.79 (for 9 fruit and vegetable items). Applications/Conclusions Nutrition professionals can use these methods to v alidate items for food behavior checklists for specific populations. The it ems described here may be useful when designing instruments to administer t o low-income women in a community setting.