Metabolizable Energy (ME)

Metabolizable energy is the portion of a food's gross energy that a dog can actually digest, absorb, and use. It is what shows up on bags as 'kcal/cup' or 'kcal/kg'. ME accounts for the energy lost to indigestible fiber, urinary excretion, and heat. ME is the right number to use for portion calculation. Two foods at the same crude protein and fat percentages can have different ME values depending on their ingredient digestibility. A higher-quality recipe with more digestible ingredients may have lower 'apparent' calories per cup but the same usable energy as a less-digestible recipe with higher numbers.