vegetables w/ fiber
It swells as it absorbs water. Some vegetables that have soluble fiber include peas, with 8.8 grams of fiber per cup, carrots, 1.7 grams each, psyllium, 16 grams per ounce, and black beans, with 10.4 grams per cup. Insoluble fiber, also called roughage, does not dissolve in the digestive tract.
Mushrooms have some of the lowest fiber content of all vegetables, with only 0.5 grams per 1/2 cup raw. Cooking mushrooms will slightly increase their fiber content. As a result, the same serving of cooked mushrooms has 1.7 grams of fiber, which is still low enough for a low-fiber diet.