Soluble vs. insoluble fiber
Dietary fiber is the part of plant-based food that mostly passes through your digestive system without breaking down or being digested. There are two types of fiber: soluble and insoluble fiber.
Soluble fiber dissolves in water, and includes plant pectin and gums. Insoluble fiber doesn’t dissolve in water. It includes plant cellulose and hemicellulose.
Most plants contain both soluble and insoluble fiber, but in different amounts. Fiber is an important part of a healthy diet and supports many different body systems.
Read on to learn more about the differences, pros, and cons between soluble and insoluble fiber.
Benefits of each type of fiber
Soluble and insoluble fibers have unique benefits.
As soluble fiber dissolves, it creates a gel that may improve digestion in a number of ways. Soluble fiber may reduce blood cholesterol and sugar. It helps your body improve blood glucose control, which can aid in reducing your risk for diabetes.
Insoluble fiber attracts water into your stool, making it softer and easier to pass with less strain on your bowel. Insoluble fiber can help promote bowel health and regularity. It also supports insulin sensitivity, and, like soluble fiber, may help reduce your risk for diabetes.
Dietary fiber can do a lot to support gut health, which researchers are increasingly learning plays a role in many health issues throughout your body. The right amount of overall dietary fiber can:
- control body weight
- control and possibly prevent hypertension
- help balance cholesterol levels in blood
- regulate bowel movements and prevent hemorrhoids
- regulate blood sugar
- regulate your body’s satiation signals, which let you know when you’re full
- lower risk of colon cancer
- lower risk of breast cancer
- lower risk of diabetes
- require more chewing, which slows down your meals and aids digestion
Did you know?
Increasing your intake of dietary fiber by two servings of whole-grain products each day might lower your risk for type 2 diabetes by as much as 21 percent.
Risks of taking too much fiber
Too much fiber can cause gas, pain, and abdominal bloating. Talk with your doctor if you experience these side effects. It’s most likely that you’re consuming less fiber than you need, however, not more.
If you want to increase your fiber intake, it’s important to increase your servings slowly over time. In order to see all of the benefits of eating fiber, you also need to make sure that you’re drinking enough water every day.
Dietary fiber is a natural and important part of a balanced diet. It’s estimated that people in the United States get less than half of their recommended fiber each day. Learn more about daily recommended amounts of fiber.
Following are the recommendations for your total dietary fiber, which includes both soluble and insoluble types:
|men, age 50 and under||38 grams per day|
|women, age 50 and under||25 grams per day|
|men, over 50||30 grams per day|
|women, over 50||21 grams per day|
You can increase your daily fiber intake by eating a variety of fruits, vegetables, legumes, and grains. Here are examples of foods you can eat to increase your fiber intake:
- 1 slice of whole-wheat bread has approximately 3 grams of fiber
- 1 cup of cooked oatmeal has approximately 4 grams of fiber
- 1 cup of cooked black beans has approximately 15 grams of fiber
Powder and pill supplements may be necessary on occasion, but real food is preferable because it will also give you the vitamins and nutrients you need to round out your diet. Talk with your doctor before relying on supplements.
Here are some tips to keep in mind when choosing foods with dietary fiber:
- Canned and processed foods have less fiber than fresh, whole foods.
- Foods with added fiber might have “chicory root” or “inulin” listed on the ingredients list.
- Plants have varying levels of insoluble and soluble fibers, so it’s most important to eat a wide variety of fruits, vegetables, and grains, to get the benefits of both kinds of fiber.
- Consult a pediatrician before giving your child any fiber supplements because they could be habit-forming.
Sources of soluble fiber
Good sources of soluble fiber include:
- citrus fruit
To add more soluble fiber to your diet:
- Sprinkle psyllium flakes on top of your food.
- Make a hearty soup with broth and carrots, barley, peas, and beans for a filling and healthy meal.
- Snack on apples, oranges, or grapefruit when you’re craving something sweet.
- Try making your own dried fruit for healthy, convenient food.
Sources of insoluble fiber
Good sources of insoluble fiber include:
- whole-wheat flour
- wheat bran
- green beans
To add more insoluble fiber in your diet:
- Start your day with whole grain toast, oatmeal, or a fibrous cereal for breakfast.
- When baking, replace some or all flour with whole-wheat flour.
- Have nuts on hand for healthy snacks.
- Buy fresh cauliflower and green beans at the store. Rinse and chop them as soon as you get home, and keep them on hand to steam or eat raw as a snack or side dish to a meal.
Both soluble and insoluble fibers are important for a healthy diet. They help fight diabetes and some cancers, and support cardiovascular and digestive health.
Many Americans don’t get enough fiber in their daily diet.
You can slowly and easily eat more real food that’s naturally high in fiber to gain short- and long-term benefits. Here are more high-fiber foods to add to your diet.