Estimating the prevalence of inadequate nutrient intakes in a healthy elderly population: Validity of classification and probability methodologies

Abstract

The evaluation of dietary intake is an essential part of nutritional surveys and provides estimates of risks of dietary deficiency. In order to test the validity of these estimates, the prevalence of inadequate intake in a healthy elderly population (n=82) was calculated from a 7-day food record using two different methods and then compared to the prevalence of nutritional deficiencies evidenced by laboratory assessments. With the probability method, the risk for each individual to have an intake below its own requirement is calculated. In contrast, the classification method compares the intake of each subject to a cut-off point set a priori below which the intake is presumed to be inadequate. For each nutrient considered, probability analyses consistently yielded a predicted prevalence lower than the currently used classification method (<100% or <67% of dietary standards). Comparisons with biochemical and hematological values indicate that the probability approach provides a valid estimation of the prevalence of dietary risks of deficiency and should be preferred to the classification method in the evaluation of nutritional status of healthy elderly persons.