What we all share is an ability to digest carbohydrates (sugars/starches), proteins and fats/oils. That comes in various degrees and may be augmented by bacteria so that we can digest high order sugars such as those found in wood.
On the other hand that ability ranges from 0% expression all the way to 100% expression.
Your typical prey animal eats lots of carbs and oils. Your typical predator animal eats lots of protein and fats.
Even among humans there are vast differences. Far Northern peoples almost universally express diabetes upon encountering a diet rich in carbohydrates. Clearly it is our fate to subsist on beluga whale, seals and fish.
Yet others begin perishing when the amount of protein in the diet exceeds 40% over a long enough period of time.
I perish when beer drops below 15%