Amino acids: total essential amino acids

Different definitions exist for which amino acids should be included in total essential amino acid values. Some definitions include only the eight amino acids that cannot be synthesized in the human body: isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Other definitions also include arginine and histidine because they are essential for infants, or cystine and tyrosine because of their sparing effects on the dietary requirements for methionine and phenylalanine. The tagnames for total essential amino acid values specify which amino acids were included in the total. Tagnames are also available to identify values for which it is unknown which amino acids were included in the total.

The total essential amino acid tagnames also distinguish whether the value is expressed per quantity of edible portion of food, per quantity of nitrogen in the food, or per quantity of protein in the food. The tagnames for values expressed per quantity of edible portion of food are subsidiary to the <comp> structural tag, while the tagnames for values expressed per quantity of nitrogen or protein are subsidiary to the < drvd-comp > structural tag.

All tagnames that can be assigned to total essential amino acid values are listed below with their respective structural tags.