Peter Attia

But the exact quantity is going to vary across plants, though vegetables will typically contain more.

And within fruits, peels and skins would also contain more than the meat of the fruit, so to speak.

When it comes to soluble fibers, some foods are especially high in certain types.

So, for example, oats are packed with beta-glucan, which is a soluble gel-forming fiber that's also fermentable by the gut biome.

So when you eat oats, you're getting insoluble fiber from cellulose and then the beta-glucan, and you're getting both gel formation and the fermentation-driven prebiotic effects that make those short-chain fatty acids, which also have a positive and favorable effect on blood glucose.

Now, beans, on the other hand, don't contain any single dominant fiber.

They're high in fiber overall because they provide a diverse mix, including resistant starches, which I want to come back and talk about.

insoluble fiber, and soluble fibers with varying degrees of fermentability.

So when you get fiber from whole food sources, just remember you're getting a mixture of fiber types as opposed to just one.

Yeah, yeah.

This is actually something that I learned in the prep for this podcast.

I didn't appreciate the temperature component of this.

So a resistant starch is a type of insoluble fiber where the word resistant is referring specifically to the fact that they resist digestion.

Now they're subdivided into five types, RS1 to RS5, which actually I think would really be a better car name, the Audi RS1 or the Audi RS5, but we'll put that aside for now.

But the most common types we encounter are RS1, RS2, and RS3.

So RS1 are the starches that are physically inaccessible to digestive enzymes in the GI tract.

They're typically found in whole grains, seeds, legumes, and other minimally processed foods that are high in fiber.

RS-2 are naturally resistant starch granules.

So they're present in raw potato starch, unripe green bananas, anybody's up for that, and some high amylose maize starches.

That's just a type of corn.