why do only carbs, fats and protein have calories?

Question

Okay so we all know that we need energy to make our bodies work and that energy comes from macronutrients (ie carbs, fat, protein), but why from ONLY those three things? Isn’t there other forms of store energy in plant and animal matter that we could use to power our bodies? After all aren’t those three macro nutrients just chains of carbon and hydrogen with some other stuff hanging on, surely there most be other compounds that are similar enough that we could use as an energy source ?

In: Biology

Answer 1

Our bodies evolved to specifically eat those things. We can’t even process all carbs, take fiber or grass for example. There’s no reason to research alternative sources of energy when our body runs on those 3 and those 3 alone.