I really don't understand this craze about the fiber, because in a real, whole food diet it shouldn't be of any concern whether the fiber is low or high, there is simply no low or high (well, I guess there can be a high, but you have to make really poor food choices, like eating just the skins of vegetables).

How does fiber support or "feed" the colon? We eat the food with the fiber, then the fiber reaches the colon and the gut bacteria eat it, and finally the gut bacteria poop short-chain fatty acids, of which the most important one in our story is butyrate, because it makes the vast majority of the nutrition requirement of colon cells.

What happens if you don't eat fiber? As we are in a real, whole food diet, this basically means that we aren't getting any carbs in either, so we will be going through some ketogenic phases and we will have some ketones flowing around our body, such as β-hydroxybutyrate (note the butyrate part there), which will feed the colon cells.

Like, damn, it seems that our body has so many redundancy systems. But we managed to outsmart it by stripping the foods off fiber and presenting it with something that it would never see in constant abundance in nature: refined carbs. And now we say, oh yeah it is very important to have 30 grams of fiber per day. How did that number even come to be? If one day I want to do 10 apples, then the fiber intake should be 50 grams, because that is how much fiber is in 10 apples. If another day I want to do 1 kg of sardines with their nice shiny skin and their mildly crunchy bones, then the fiber intake could be 0 grams with no issues whatsoever, because I'm not getting in any carbs and my liver will make β-hydroxybutyrate!