We give our food water, but it doesn't quench our thirst. We give our food grass, but it doesn't tear up our teeth. Our food has poop in it, but doesn't taste of poop. Is there any evidence that steroids which are digested by a cow linger in its body as an active substance for years, in a large enough quantity to have a steroid effect after going through another creature's digestive system?
Isn't obesity rather well explained by cheap easily available food, carb heavy diet and increasingly sedentary lifestyle?
Otherwise, cows grow to much bigger than people, much quicker than people do. Why don't their natural growth hormones affect us in the same way?