Consequences of utilizing reduced nutrient data bases for estimating dietary adequacy.

The USDA Nutrient Data Base (NDB) used to calculate dietary intake in the Nationwide Food Consumption Survey of Individuals 1977-1978 (NFCS) was reduced to two levels. Both reduced data bases were used in analysis of 3-day dietary records collected on 7,914 individuals during the first quarter of that survey. Baseline nutrient intake values for energy and 14 nutrients for 22 sex-age groups were calculated prior to NDB reduction. After reduction, nutrient intake values were again calculated. The magnitude of variation was determined, and ANOVA was used to evaluate those variations at both substitution levels. The NDB reductions resulted in significant alterations in calculated nutrient intake and interactions between NDB type and various sex-age groups. However, the magnitude of the differences in calculated nutrient levels between the original and reduced data bases was, generally, quite small. The notable exception was in the under-1-year sex-age group. On the basis of this study, predictions of nutritional adequacy for the NFCS using the smaller data bases would show essentially the same trends as obtained from the original data base.