Evaluation of Dietary Assessment Tools Used to Assess the Diet of Adults Participating in the Communities Advancing the Studies of Tribal Nations Across the Lifespan Cohort

Background Accurate assessment of dietary intake is essential for researchers and public health practitioners to make advancements in public health. This is especially important in Native Americans who display disease prevalence rates that are dramatically higher than the general US population. Objective To evaluate three dietary assessment tools: dietary records, a food frequency questionnaire (FFQ), and a shellfish assessment survey among Native American adults from the Communities Advancing the Studies of Tribal Nations Across the Lifespan (CoASTAL) cohort. Design The CoASTAL cohort was composed of randomly selected individuals from three tribal registries of Pacific Northwest Tribal Nations. This cross-sectional study used data from the baseline of CoASTAL and was restricted to the non-pregnant adults (aged 18 years or older) who completed the shellfish assessment survey (n=500), an FFQ (n=518), dietary records (n=444), weight measures (n=493), and height measures (n=496). Paired t tests, Pearson correlation coefficients, and percent agreement were used to evaluate the dietary records and the FFQ with and without accounting for plausibility of reported energy intake (rEI). Sensitivity and specificity as well as Spearman correlation coefficients were used to evaluate the shellfish assessment survey and the FFQ compared to dietary records. Results Statistically significant correlations between the FFQ and dietary records for selected nutrients were not the same by sex. Accounting for plausibility of rEI for the dietary records and the FFQ improved the strength of the correlations for percent energy from protein, energy from carbohydrate, and calcium for both men and women. In addition, the association between rEI (dietary records and FFQ) and weight became significant when the sample was limited to plausible rEI. The shellfish assessment survey was found to similarly assess shellfish consumption in comparison to the FFQ. Conclusions These results support the benefit of multiple measures of diet, including regional and culturally specific surveys, especially among Native Americans. Accounting for plausibility of rEI may ensure more accurate estimations of dietary intakes. J Am Diet Assoc. 2010;110:65-73.