The mechanism behind why more fiber helps is pretty straightforward:
Insoluble fiber speeds up gut motility. Faster gut motility means less time for toxins to sit and absorb in your gut.
Also, fermentable fibers serve as substrate for gut microbes, producing short-chain fatty acids (butyrate is one - a primary fuel source for colonocytes - the cells that line your colon).
It also lowers colonic pH, inhibiting pathogenic bacteria.
Lastly, (although there are tons more benefits I'm not listing), soluble fiber is incredible for people trying to lose weight, as highly fibrous foods increase satiety, keeping you fuller for longer.
Also, MyPlate only used "grains" as a category, with a note to make half from whole grains...not just processed carbs. Big difference. And, vegetables are the biggest category.
Adding on to that, if you workout in ANY capacity, you need simple carbs.
>I'm guessing the colon cancer thing is probably due to pollutants
> You don't actually need fiber
Hey, you know what fiber is good for? Speeding up gut motility! You know what a faster gut motility is good for! Getting toxins out of our body quicker!
In that case, wouldn't you want to include things like sorbitol?
I want to emphasize I'm not making any grand claims of advice. I'm more being skeptical of traditional advice as someone who had/has a colon issue and tried everything under the sun.
Insoluble fiber speeds up gut motility. Faster gut motility means less time for toxins to sit and absorb in your gut.
Also, fermentable fibers serve as substrate for gut microbes, producing short-chain fatty acids (butyrate is one - a primary fuel source for colonocytes - the cells that line your colon).
It also lowers colonic pH, inhibiting pathogenic bacteria.
Lastly, (although there are tons more benefits I'm not listing), soluble fiber is incredible for people trying to lose weight, as highly fibrous foods increase satiety, keeping you fuller for longer.