advert from 1974 for Cupboard Love Cat food.

Cat food is food intended for consumption by cats. As cats are obligate carnivores most commercial cat foods are fortified with supplemental nutrients. One of the most important is the amino acid derivative taurine, as cats cannot synthesize the compound. Cats fed taurine-deficient dog food may develop retinal degeneration and go blind, for example.

Energy Requirement

The energy requirement for adult cats range from 60-70 kcal metabolizable energy/kg body weight per day for inactive cats to 80-90 kcal/kg BW for active cats. Kittens at five weeks of age require 250 kcal/kg BW. The requirement drops with age, to 100 kcal/kg BW at 30 weeks and to the adult requirement at about 50 weeks. Gestating cats require about 90-100 kcal/kg BW and lactating cats 90-270 kcal/kg BW depending on litter size.

Info gleaned from Wikipedia