Beyond daily totals: meal-level digestible indispensable amino acid score reveals how food groups shape protein quality in vegan diets.

Introduction: Vegan diets rely solely on plant-based proteins, which often supply fewer digestible indispensable amino acids (IAAs) than omnivorous diets. Low protein quality can leave IAAs undersupplied even if the protein intake meets the recommended intakes. Mixtures of plant-based foods in meals can complement limiting IAAs and improve the synchronized delivery of all IAAs for optimal metabolic function. Assessing how food group compositions differ among meals of varied protein quality is essential to determine the ideal proportions of plant-based foods to improve the Digestible Indispensable Amino Acid Score (DIAAS) of vegan meals. Methods: The DIAAS was calculated for each meal found in the 4-day food diaries of 193 New Zealand vegans. Principal component analysis and k-means clustering were applied to identify food groups associated with meals of varying DIAAS, and meal level clusters were compared to participants' daily protein intake. Results: Eight distinct meal clusters emerged. Lower-DIAAS meals were characterized by higher quantities of fruit, grain foods, potatoes, and sugary condiments with significantly lower ( Discussion: Deliberate meal-level complementation of plant-based foods is necessary to ensure protein quality in vegan dietary patterns.