International Symposium: Dietary Protein for Human Health

Evaluating the Utility of USDA Protein Ounce Equivalents for Plant-Based Diets: A Comparative Analysis of Essential Amino Acid Contents

Background:
Translating nutrition research into practical dietary advice is challenging, particularly regarding essential amino acid (EAA) requirements. The USDA introduced "Protein Ounce Equivalents" (Oz Eq) in 1992 to help consumers monitor protein intake and assist federal programs in complying with dietary guidelines. However, Oz Eq does not accurately reflect protein or EAA contents in designated “protein foods”.

Objectives:
This study assesses disparities in protein and EAA contents among foods labelled as 1 Oz Eq and proposes an alternative guideline, "EAA-9 Oz Eq," accounting for EAA density. The objective is to provide precise dietary recommendations, catering to individual needs and promoting precision nutrition for diverse populations.

Methods:
To explore the relationship between plant-based proteins and EAA requirements, USDA food composition data were used to model various ratios of animal-to-plant protein foods. Models were designed to generate meal patterns aligned with USDA Oz Eq. The analysis considered the minimum Recommended Daily Allowance (RDA) for each of the nine EAA and diverse protein-food groups.

Results:
Foods labelled as 1 Oz Eq had  significant differences in total protein and EAA content. Oz Eq designations for foods like eggs, peanut butter, and almonds showed varying nutrient profiles, particularly in critical limiting EAA, such as Lysine and Leucine. An inverse relationship was observed between plant-based protein meal patterns and EAA nutrient density, this could impact the likelihood of meeting EAA requirements and necessitate higher protein and calorie intakes. EAA-9 represents the only approach currently available that accurately reflects EAA requirements for dietary planning.

Conclusions:
The USDA Oz Eq approach may imprecisely guide dietary choices, particularly in plant-based diets, due to lower EAA content among designated foods. "EAA-9 Oz Eq" guidelines are proposed, emphasizing EAA density for more accurate dietary recommendations. This approach promotes informed dietary choices, fostering precision nutrition for balanced nutrition regardless of dietary preferences.