Dietary variety within food groups: association with energy intake and body fatness in men and women

Background: Short-term experimental studies suggest that dietary variety ma y influence body fatness but no long-term human studies have been reported. Objective: The purpose of this study was to determine whether dietary varie ty within food groups influences energy intake and body fatness. Design: Seventy-one healthy men and women (aged 20-80 y), who provided accu rate reports of dietary intake and completed a body-composition assessment, were studied. Results: Dietary variety was positively associated with energy intake withi n each of 10 food groups (r = 0.27-0.56. P < 0.05), In multiple regression analysis with age and sex controlled for, dietary variety of sweets, snacks , condiments, entrees, and carbohydrates (as a group) was positively associ ated with body fatness (partial r = 0.38, P = 0.001) whereas variety from v egetables was negatively associated (partial r = -0.31, P = 0.01) (R-2 = 0. 36, P < 0.0001). Ln separate models, both a variety ratio (variety of veget ables/variety of sweets, snacks, condiments, entrees, and carbohydrates) an d percentage dietary fat were significant predictors of body fatness (contr olled for age and sex, partial r = -0.39 and 0.31, respectively, P < 0.01). However, dietary fat was no longer significantly associated with body fatn ess when the variety ratio and dietary fat were included in the same model. Conclusions: Our data, coupled with those of previous shortterm studies, su ggest that a high variety of sweets, snacks, condiments, entrees, and carbo hydrates coupled with a low variety of vegetables promotes long-term increa ses in energy intake and body fatness. These findings may help explain the rising prevalance of obesity.