in its current form as a measure of protein quality in human diets." Also, the scientific community has raised critical questions about the validity of PDCAAS (the validity of the preschool-age child amino acid scoring pattern, the validity of the true fecal digestibility correction and the truncation of PDCAAS values to 100%). Capped score In addition, the fact that four proteins, all with different amino acid profiles, receive identical scores of 1.0 limits its usefulness as a comparative tool. Since they have different compositions, it is natural to assume that they perform differently in the human body and should have different scores. In short, this method, however, gives no distinction of their performance relative to each other, because after they pass a certain point, they are all capped at 1.0 and receive an identical rating. This is because in 1990 at a FAO/WHO meeting, it was decided that proteins having values higher than 1.0 would be rounded or "leveled down" to 1.0 as scores above 1.0 are considered to indicate the protein contains essential amino acids in excess of the human requirements. Reference pattern This reference pattern is based on the essential amino acid requirements for preschool children aged 1–3 years as published in Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005). Adults aged 18+ will have slightly lower requirements. Example values A PDCAAS value of 1 is the highest, and 0 the lowest. The table shows the ratings of selected foods. (others) See also Amino acid score Protein quality Net protein utilization Nitrogen balance References Detailed Anaysis and Study of Collagen Protein Synthesis and Absorption from an industry source, all content unverified Nutrition Proteins