What to know about fiber: how soluble and insoluble fiber differ

Fiber is an important part of a healthy diet. It is essential to our overall health and keeps our digestive system moving smoothly.

• Promotes regularity: Fiber adds bulk to your stool and softens it, preventing constipation.
• Improves gut health: It helps sweep waste through your intestines and feeds a healthy gut microbiome, which can reduce your risk for colon cancer.
• Balances blood sugar: Fiber slows down the digestion and release of sugar into your bloodstream, leading to more stable blood sugar levels.
• Aids weight management: Fiber-rich meals tend to be lower in calories and keep you feeling full much longer.

How Much Fiber Do I Need?

The National Academy of Medicine recommends the following daily fiber intake based on age and sex:

Soluble vs. Insoluble Fiber

For optimal health, you need a balance of both types of fiber:

• Soluble Fiber: This type dissolves in water to form a gel-like material. It slows down digestion and is highly effective at lowering cholesterol and blood sugar.
  • Common sources: Oats, beans, apples, bananas, citrus fruits, avocados, carrots, and psyllium, which is commonly used in fiber supplements.
• Insoluble Fiber: This type does not dissolve in water. It acts like a broom, adding bulk to your stool and helping food move more efficiently through your digestive system to prevent constipation.
  • Common sources: Whole wheat, nuts, beans, potatoes, cauliflower, broccoli, and leafy greens.

How Can I Get More Fiber in My Diet?

Aim to get both types of fiber from a variety of whole-food sources. A great goal is to include a good source of fiber at every single meal.

• Stay hydrated: To avoid discomfort as you increase your fiber intake, increase your liquid intake at the same time.
• Eat more beans: Beans are an incredibly rich source of both soluble and insoluble fiber. Just 1/2 cup of black beans boasts around 6 grams of fiber, and 1/2 cup of kidney beans comes in at nearly 8 grams. Lentils, navy beans, and pinto beans are similarly excellent options.
• Load up on berries: Berries are fiber powerhouses. Blackberries and raspberries contain about 8 grams of fiber per cup. Tossing a handful of raspberries, blackberries, or blueberries onto your morning oatmeal adds natural sweetness and a massive fiber boost.
• Sprinkle on seeds: Chia, sesame, pumpkin, and sunflower seeds add a satisfying crunch and flavor to salads, yogurts, and cereals, while also providing a healthy dose of fiber.
• Use the Healthy Eating Plate Method: Developed by Harvard nutrition experts, this method is a simple visual guide for meal building. Half of your plate should be fruits and vegetables, one-quarter should be lean protein like meat, fish, tofu, beans, or nuts, and one-quarter should be whole grains or starchy vegetables.

Source Note

For more information about the Healthy Eating Plate, visit The Nutrition Source from the Department of Nutrition at the Harvard T.H. Chan School of Public Health.