This latest deep dive explores the critical methods used to determine protein quality, moving beyond simple consumption to understand how much of a nutrient is truly utilized by the body. We examine the complex distinction between bioavailability—the proportion of amino acids absorbed in a form suitable for protein synthesis—and digestibility, which is often used as a more repeatable, though less direct, estimate of a nutrient’s utility.

Topic Outline

• Bioavailability vs. Digestibility

◦ Defining bioavailability as the "true" utility of a nutrient compared to digestibility, which measures the "disappearance" of a nutrient from the digestive tract.

• Direct Measurement of Bioavailability

◦ Th ...