Are there negative consequences of eating large amounts of fiber (if you feel fine with it)?

Question

I have started to change my diets two years ago, and are now eating large amounts of fiber every day - 'large amounts' meaning far above the recommended 30 g, typically 100 - 150 g per day.
I have read about possible complications like abdominal pain, bloating, diarrhea, or constipation; I have none of these, I am doing fine with it for months.

Question: are there any known short or long-term adverse effects from such high fiber intakes?

Answer 1

Not at all. Studies have shown that a large amount of fibers is a protective factor against colo-rectal cancer for example. Actually, as you said, only effects are some digestive troubles, since fibers are cut and destroyed by bacterias in colon : those bacterias produce gas, that's why you might feel uncomfortable. But if you don't have that, go on !

One important point : you don't have to REPLACE something by fibers. I mean, it's good to eat a lot of fibers, but not only fibers. Don't forget proteins !

Answer 2

There are no negative consequences, IF you eat in the proper way.

With this statement I am referring to eat every component of the diet, like carbs, fats, proteins, vitamins and of course fibers. This is essential.

The main problem with people that eat lots of fibers, is that they feel full fast and usually won't eat all the proper components. Problems you have provided, like abdominal pain, bloating, diarrhea, or constipation are in fact caused of not eating good enough: vitamins deficit can lead to abdominal pain, coagulation problems and so on; protein deficit can leat to muscular problem, problems in the healing of scars or in general dermatological problems and so on.

So, eating a lot of fiber has no side effect if you integrate the other component of the diet.