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 may influence body fatness but no long-term human studies have been reported. OBJECTIVE The purpose of this study was to determine whether dietary variety within food groups influences energy intake and body fatness. DESIGN Seventy-one healthy men and women (aged 20-80 y), who provided accurate reports of dietary intake and completed a body-composition assessment, were studied. RESULTS Dietary variety was positively associated with energy intake within 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, entrées, and carbohydrates (as a group) was positively associated with body fatness (partial r = 0.38, P = 0.001) whereas variety from vegetables was negatively associated (partial r = -0.31, P = 0.01) (R2 = 0.46, P < 0.0001). In separate models, both a variety ratio (variety of vegetables/variety of sweets, snacks, condiments, entrées, and carbohydrates) and percentage dietary fat were significant predictors of body fatness (controlled 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 fatness when the variety ratio and dietary fat were included in the same model. CONCLUSIONS Our data, coupled with those of previous short-term studies, suggest that a high variety of sweets, snacks, condiments, entrées, and carbohydrates coupled with a low variety of vegetables promotes long-term increases in energy intake and body fatness. These findings may help explain the rising prevalence of obesity.