Diet and Nutrition

The Difference Between Soluble and Insoluble Fiber

What Is Soluble and Insoluble Fiber?

Dietary fiber is a carbohydrate, but unlike other carbs, it cannot be broken down into digestible molecules. In other words, fiber goes through the gastrointestinal system relatively intact, which helps support and aid the digestive system in its processes.

Fiber is divided into two categories: soluble and insoluble fiber. Both types play an important role in regulating weight, cholesterol, and blood sugar. According to several studies, you can even decrease your risk for cancer by adding fiber to your daily diet. Though there are many foods that contain both soluble and insoluble fiber, the actual content in these foods varies.

Good sources of fiber include:

  • Oatmeal
  • Blueberries
  • Apple
  • Barley
  • Beans
  • Lentils
  • Peas
  • Citrus fruits
  • Brown rice
  • Cauliflower
  • Wheat
  • Cucumber
  • Potato
  • Tomato
  • Nuts
  • Carrots

According to the National Academy of Medicine, women under the age of 50 should consume about 25 grams of fiber a day, while those who are over 50 must consume about 21 grams a day. Men below the age of 50 should consume about 38 grams of fiber a day, while those over 50 years old must consume about 30 grams a day.

A high-fiber diet is always healthy. Typically, fiber comes from plant-based foods, like vegetables, nuts, fruits, and whole grains. This is why doctors usually recommend patients to eat fruits like apples, or pears, with the skin because they are usually packed with insoluble fibers.

What is soluble fiber?

Soluble fiber dissolves in water and forms a gel-like substance. Soluble fiber is very beneficial for the human body as it helps decrease the levels of sugar in the blood and normalizes blood cholesterol levels. Some types of soluble fiber are gum, pectin, and mucilage. Soluble fibers can offer a lot of benefits, and be found in peas, blueberries, oatmeal, beans, and lentils.

Some of these health benefits include:

  • Protects against diabetesAs they are not well-absorbed in the human gastrointestinal system, they do not contribute into spikes of sugar in the blood, lowering your risk for type 2 diabetes. In cases when a person is already diagnosed with diabetes, regardless if it is type 1 or type 2 diabetes, keeping soluble fiber as part of your diet can help you maintain your blood glucose levels.
  • Protects against other health diseases: Soluble fiber attaches to cholesterol particles and help eliminate them from the body. If cholesterol is eliminated regularly from the body, its levels will be lowered. When cholesterol levels are within the normal range, the risk of developing various heart diseases including atherosclerosis, heart attack, and stroke is lowered. 
  • Supports weight loss: High-fiber foods are generally low in calories. Soluble fiber helps stimulate the gastrointestinal system by increasing digestion and bowel movements. They will also make you feel full, and by feeling full, you won't need to eat as often because you won't get hungry as quickly. 
  • Maintains regular and healthy bowel movements: They soak in water from the body while they pass through the gastrointestinal system. This way, soluble fiber helps prevent constipation and diarrhea.

What is insoluble fiber?

Unlike soluble fiber, insoluble fiber does not dissolve in water. In the human body, insoluble fiber retains its shape and passes through the gastrointestinal system intact, and speeds up the passage of food through the digestive system, preventing constipation. Potatoes, tomatoes, brown rice, cucumbers, cauliflower, and wheat are usually a great source of insoluble fiber. The benefits of insoluble fiber are:

  • Helps lose extra pounds: Just like soluble fibers, insoluble fibers also prevent you from feeling constantly hungry while improving your digestive health and regular bowel movements.
  • Keeps the gastrointestinal system healthy: Insoluble fibers not only prevent constipation, they can also aid in regular bowel movements, improve hemorrhoids, and control fecal incontinence.

Foods that Are Low in Fiber 

High-fiber foods are always recommended for a good overall health as they have various benefits. However, not everyone should consume high-fiber foods. In certain cases, fiber should be avoided when the gastrointestinal system needs to take a rest, especially for people diagnosed with Crohn’s disease. Low-in-fiber foods have other important health benefits, so make sure to include them in your diet with your daily dose of fiber.

  • Red meat: Beef, veal, lamb, and pork contain no fiber at all. But, while animal-based foods do not contain fiber, they do offer other health benefits. Normally, these foods should be a part of our diet, but they should also be paired with side dishes with a certain amount of fiber.
  • Fish and seafood: Tuna, crab, shrimps, oysters, salmon, swordfish, and other types of fish contain no dietary fiber. Instead, they provide us with other vitamins, minerals, and proteins that we need. 
  • Eggs and poultry: Chicken, duck, and turkey contain no fiber at all, and this means you won’t get any fiber from eggs. However, they have other health benefits. They contain high levels of vitamins, proteins, and minerals, including potassium.
  • Beverages: Water, tea, coffee, cranberry juice, different cocktails, and soft drinks do not contain fiber. On the other hand, fruit juices, smoothies, and all the other drinks that are rich in fruits or fruit pulp contain a variable amount of fiber.
  • Dairy products: Yogurt, ice cream, sour cream, cheese, butter, and milk, do not contain fiber. However, they are rich in calcium, iron, potassium, phosphorus, vitamin A, and vitamin D.

Key Takeaways

  • Fiber is a type of carbohydrate. 
  • There are two types of dietary fiber: soluble and insoluble. 
  • Fiber has a lot of health benefits, not only for the gastrointestinal system, but for the entire body.