There are two types of fiber we can get from food: soluble and insoluble fibers. They have some of the same beneficial effects and come from similar sources, so let’s discuss their differences and why they both matter.
Soluble fiber is "soluble" in water. When mixed with water it forms a gel-like substance and swells. Soluble fiber has many benefits, including moderating blood glucose levels and lowering cholesterol. The scientific names for soluble fibers include pectins, gums, mucilages, and some hemicelluloses.
According to the Mayo Clinic, a diet rich in soluble fiber can help lower your level of LDL, or “bad cholesterol.” It may also help lower blood pressure! So add some beans, legumes, berries, or vegetables into your diet daily to reap the rewards.
Insoluble fiber does not absorb or dissolve in water. It passes through our digestive system in close to its original form. Insoluble fiber offers many benefits to intestinal health, including a reduction in the risk and occurrence of hemorrhoids and constipation. The scientific names for insoluble fibers include cellulose, lignins, and also some other hemicelluloses. Most of insoluble fibers come from the bran layers of cereal grains, but also in unbreakable fibers from some fruits and vegetables, like in celery or skins of tomato.
The Institute of Medicine recommends adults under 50 years old get around 38 grams fiber for men and 25g for women. If you're over 50, aim for 30g for men and 21g for women. Most of us get only around 15g fiber per day.
Since dietary fiber is found only in plant products (i.e., nuts, whole grains, legumes, fruits and vegetables), these are essential to a healthy diet.
beans, peas, lentils, oatmeal, oat bran, nuts, seeds, psyllium, apples, pears, strawberries, and blueberries
whole grains, barley, whole-grain couscous, brown rice, bulgur, wheat bran, nuts, seeds, carrots, cucumbers, zucchini, celery, green beans, dark leafy vegetables, raisins, nuts, grapes, and tomatoes
This sample menu for a day gives you 37 or more grams of fiber:
Breakfast: 1 high fiber wheat toast (5g fiber), 2 tbsp natural peanut butter (2 g fiber) 1 cup sliced strawberries (4 g fiber)
Lunch: Turkey sandwich made with 2 slices of whole wheat bread, lettuce, and tomato (8 grams of fiber), and an orange (3.1 grams of fiber)
Dinner: Grilled fish with a salad of romaine lettuce and shredded carrots (2.6 grams of fiber), half a cup of spinach (2.1 grams of fiber), and half a cup of lentils (7.5 grams of fiber)