He found that when it comes to calories per kilogram of muscle, humans are firmly in the middle of the pack. Musk ox (which, if you’re curious, tastes like beef), fish, cows, birds, bears, and beavers all contain more calories per pound of muscle than humans do. We have more calories per kilogram of muscle than some species—like reindeer and horse. But those animals are much larger than humans. A reindeer has literally twice the muscle of your typical human male, so you'd have to kill more people than reindeers to stay well fed.