Protein
 Amino Acids
  Arginine
  Histidine
  Isoleucine
  Leucine
  Lysine
  Methionine (spared by cystine)
  Phenylalaine (spared by tryosine)
  Threonine
  Tryptophan
  Valine
  Taurine

Fat
 Linoleic acid
 Arachidonic acid
 +/-Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)

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  Unable to convert carotenoids to vitamin A/retinol
  Inadequade synthesis of vitamin D
    (even if hairless and exposed to sunlight/UV radiation)
  Unable to use tryptophan for niacin synthesis
  Unable to synthesize adequate amount of taurine from sulfur amino acid,
    methionine, and cysteine
  Unable to synthesize citrulline (needed for the urea cycle; as a result,
    a single ariginine-free but protein-containing meal can cause death)
  Glutamic acid (high in plants and low in animals) intolerance
  Reduced ability to conserve nitrogen
  Reduced ability to desaturate long-chain PUFAs (therefore, needs
   arachidonic acid since cats are unable to make it from linoleic acid)
  Metabolically adapted to low catbohydrate diet (e.g., less activity of
   enzymes involved in glucose metabolism like glucokinase, which is the
   enzyme needed for the first step in deriving ATP from glucose)