Feeding

Cats are highly specialized for hunting and have evolved to survive on a meat-based diet.[26] Since they have a greatly reduced need to digest plants, their digestive tract has evolved to be shorter, too short for effective digestion of plants but less of a weight penalty for the rapid movement required for hunting. Hunting has likewise become central to their behavior patterns, even to their predilection for short bursts of intense exercise punctuating long periods of rest.

Source : http://en.wikipedia.org/wiki/Cat#Anatomy_and_morphology