Definitions:

• Protein-Restricted Diet: A diet that restricts intact protein to a level below the DRI for age and usually includes a prescription for essential amino acid-based medical food to ensure total protein needs are met.
• Protein-Controlled Diet: A diet that provides at least the DRI from intact protein but does not allow for unrestricted amounts of protein and may or may not include EAA.
• Intact protein: "Natural" protein from food, standard infant formula, and/or breast milk.
• High biological value protein: A protein source with all the essential amino acids in the right proportion as required by humans (e.g., animal proteins).
• Essential amino acid medical foods: Nutritionally complete and/or incomplete formulas that contain only essential amino acids (i.e., omits non-essential amino acids).
• BCAA supplements: Dietary supplements that contain only isoleucine, leucine, and valine.

Abbreviations:

ARG, arginase deficiency

ASA, argininosuccinic acid lyase deficiency

BCAA, branched-chain amino acids

CA-VA deficiency, carbonic anhydrase VA deficiency

CIT-I, argininosuccinic acid synthetase deficiency (citrullinemia type I)

CPS, carbamoyl phosphate synthetase 1

CTLN2, citrullinemia type II

DRI, dietary reference intakes
DXA, dual energy X-ray absorptiometry

EAA, essential amino acids

HHH syndrome, hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (ornithine translocase deficiency)

IV, intravenous

LPI, lysinuric protein intolerance

MCT, medium chain triglycerides

NAGS, N-acetyl glutamate synthetase deficiency

NBS, newborn screening

NICCD, neonatal intrahepatic cholestasis caused by citrin deficiency

NPO, nothing by mouth

OAT, ornithine aminotransferase deficiency (gyrate atrophy)

OTC, ornithine carbamyltransferase deficiency

UCD, urea cycle disorder