Objective: To examine the relationship between variety scores of food groups (between and within food groups) and the probability of nutrient adequacy in Tehranian men.
Design: A cross-sectional study assessing food intake by two 24-h recall questionnaires. Dietary diversity was defined according to diet quality index revised, which was used by Haines et al in 1999. The mean probability of adequacy across 14 nutrients was calculated using the Dietary Reference Intakes.
Setting: District 13 of Tehran, Iran.
Subjects: A total of 295 males, aged 18 y and over.
Results: Whole grain variety mostly correlated with protein and vitamin B2 (r=0.3, P<0.05). Fruit variety was correlated with vitamin C (r=0.4, P<0.05). Dairy variety was correlated with calcium intake (r=0.4, P<0.05). Meat variety was correlated with protein intake (r=0.3, P<0.05). Most subjects failed to meet vitamin B6, zinc, magnesium, calcium, copper, and vitamin B12 adequacy. Energy intake was a strong predictor of the mean probability of adequacy in models controlled for age, body mass index, education level and job status (model R2=0.48). Adding the number of servings from each of the food group to the models significantly improved the model fit (model R2=0.55). Adding the dietary variety improved the model fit significantly (model R2=0.61). Dairy variety and meat variety had the strongest association with improved nutrient adequacy.
Conclusion: Variety of different food groups is a useful indicator of specific nutrient adequacy. Hence, to determine the adequacy of a specific nutrient, the variety scores of specific food groups should be taken into account.