Fiber is the type of carbohydrate that our bodies can’t digest because we don’t have the enzymes to break it down. Instead, fiber passes through the body undigested and becomes food for the good bacteria in the large intestine. Fiber also works like a broom sweeping out bad cholesterol.
Fiber comes in two different types, soluble and insoluble. Most carbohydrate foods contain both types of fiber in varying amounts.
Current recommendations for total fiber intake are 25 grams for women and 30 grams for men per day. Most Americans are consuming less than 15 grams per day. Our ancestors ate between 50 to 100 grams per day, according to most research. So most of us could benefit from including more fiber in our diets.
Soluble fiber dissolves in water and forms a gel-like substance. It is not absorbed into the bloodstream, but it slows digestion, which gives vitamins and minerals more time to be absorbed through the intestinal walls.
It also binds to substances in the gut, such as cholesterol and sugar, preventing their absorption into the bloodstream and carrying them out in the stools. Soluble fiber also keeps you satiated longer and softens your stools for an easier exit.
Foods high in soluble fiber include:
- Brussels sprouts
- chia seeds
- flax seeds
- green peas
- psyllium husks
Insoluble fiber doesn't dissolve in water. When digested, it stays mostly intact. But like soluble fiber, it's not absorbed into the bloodstream. Insoluble fiber gives bulk to your stools so they can pass more easily, requiring less strain on your bowels. Insoluble fiber also helps promote regularity and prevents constipation.
Foods high in insoluble fiber include:
- brown rice
- coconut meat
- sweet potatoes