(P29-037-23) Adjusting for Protein Quality Using Digestible Indispensable Amino Acid Score (DIAAS) Impacts Percentage of U.S. Population Meeting Protein Requirements

Objectives: Digestible indispensable amino acid score (DIAAS), which is based on true ileal amino acid digestibility, reflects the estimated absorbed amount of the first limiting amino acid, relative to the requirement for that amino acid, in a food protein or the entire diet. The objective of this work was to simulate the percentage of the adult population with protein intakes potentially less then recommended levels after adjusting for possible DIAAS of the diet.

Methods: Data from the US National Health and Nutrition Examination Surveys for 2001-2018 for those 19+ years of age excluding those pregnant/lactating (n=44,018; 22,079 males and 21, 939 females) were used. Usual dietary protein intake in g/kg was determined using the National Cancer Institute (NCI) method using two dietary recalls and with the cut-point method being used to assess the percentage of the population below the Estimated Average Requirement (EAR) for protein of 0.66 g/kg body weight. Subsequently, we assessed the percentage of the population falling below the EAR assuming dietary DIAAS values of 0.9, 0.8, 0.7. and 0.6. The original usual protein intakes were adjusted downward by multiplying the respective intake by the dietary DIAAS values (0.9, 0.8, 0.7, 0.6), and intakes and the percentage of the population falling below the EAR were re-assessed. Analyses were stratified by age (19-50, 51-70, and 71+ y) and gender.

Results: The percentage of the population 19+ y with protein intakes < EAR after correction for DIAAS of 1.0, 0.9, 0.8, 0.7, and 0.6 was 13.2±0.4, 19.8±0.5, 29.3±0.5, 42.8±0.5, 59.9±0.5 %, respectively, with higher percentages for females than for males (10.8-21.5 percentage of the population < EAR across DIAAS range). Comparable data for those 71+ y was 19.7±0.7, 28.1±0.8, 39.8±0.8, 54.9±0.8, 71.7±0.7 %, respectively, again with higher percentages for females than for males (6.0-8.7 5 percentage of the population < EAR across DIAAS range).

Conclusions: Adjusting for dietary protein quality can have a significant impact on the adequacy of current protein intakes in US adults. This topic is particularly important to explore given the shifts in dietary patterns proposed by some. Important next steps are to quantify the range of DIAAS diets in US adults and to model the potential impact of shifting dietary patters on DIAAS scores.

Funding Sources: National Dairy Council