Comparative study of amino acid profiles in different diets

Abstract

This cross-sectional survey compared essential amino acid profiles among 312 adults following six dietary patterns in Finland between October 2019 and May 2020. Participants were stratified by dietary pattern: omnivore (n=58), Mediterranean (n=47), vegetarian (n=54), vegan (n=51), Nordic (n=52), and low-carbohydrate (n=50). Dietary intake was assessed using 7-day weighed food records with 24-hour recalls, and fasting plasma amino acids were determined by HPLC. Omnivore and low-carbohydrate diets provided highest essential amino acid intake (42.3 and 48.2 g/day), while vegan diets showed lowest (28.7 g/day). Plasma BCAAs were 18-21% lower in vegans versus omnivores. Lysine and methionine emerged as limiting amino acids in vegans, achieving only 72% and 64% of recommended intakes. All dietary groups maintained plasma concentrations within normal ranges, suggesting metabolic adaptation. The Nordic diet achieved amino acid profiles comparable to omnivorous patterns while emphasising sustainable sources.