When Serving Size Isn’t Equal: Animal Proteins Deliver More Muscle-Building Amino Acids

Purdue researchers found that two-ounce equivalents of animal-based proteins (lean pork loin and eggs) delivered more bioavailable essential amino acids into the bloodstream than the same amount of plant-based proteins (beans and almonds) in both young and older adults, suggesting protein quality can matter as much as portion size for muscle health and aging. Newer research adds nuance—soy protein often aligns more closely with animal protein, and blends of animal and plant proteins may offer advantages—while the study’s limitations include not directly measuring muscle protein synthesis and real-world portion variability.