Animals that live in nature continuously battle to get their necessary quantity of food resources. They have to scavenge for their day-to-day consumption of power, essential to survive. They are programmed by evolution to be the most efficient in obtaining power into their bodies. The sorts of food that have the highest amounts of energy in them are sugars and fats. That is the reason why animals (and human beings too) like the taste of it. It gives them a greater chance of survival. Nevertheless, when they are cared for by people, they do not require hunting anymore, so they have to utilize less power and get no workout.