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- Most people don’t get enough fiber, which can negatively affect gut health, heart health, blood sugar regulation, and body weight.
- Different fiber-rich foods provide unique benefits, so eating a variety of fruits, vegetables, legumes, nuts, seeds, and whole grains is best.
- Fiber supplements can help increase intake, but whole plant foods remain the best source.
More than 90% of women and 97% of men in the U.S. fall short of the recommended daily fiber intake. Fortunately, many fiber-rich foods, like fruits, vegetables, nuts, beans, and whole grains, are affordable, versatile, and easy to incorporate into your diet. But does it really matter where your fiber comes from? Here’s what to know about fiber, including the different types and why eating a variety of fiber-rich foods matters for overall health.
What Are the Different Types of Fiber?
Fiber is a type of indigestible nutrient that’s concentrated in plant foods, like beans, fruits, and vegetables. Fiber passes through your small intestine into your large intestine mostly intact.
There are two main types of fiber, which are categorized based on their solubility in water:
- Soluble fiber: Soluble fibers dissolve in water and can be fermented or broken down by your gut bacteria. Foods rich in soluble fiber include oats, fruits, and beans.
- Insoluble fiber: Insoluble fiber doesn’t dissolve in water. Soluble fiber passes through your digestive system intact. It’s concentrated in foods like whole grains, nuts, and seeds.
Soluble fiber plays important roles in gut and heart health. It supports beneficial bacteria in the digestive tract and stimulates the production of short-chain fatty acids (SCFAs), compounds that benefit gut health by reducing inflammation, strengthening the gut lining, and supporting healthy immune function. It also helps regulate blood lipid levels by decreasing cholesterol absorption in the gut and increasing its excretion.
Insoluble fiber adds bulk to stool, keeping bowel movements regular.
Most whole foods, like fruits, vegetables, and whole grains, contain a combination of insoluble and soluble fibers, but some are more concentrated in one than the other.
Do Fruits,Vegetables, and Whole Grains Offer Different Benefits?
While all plant foods, such as fruits, vegetables, beans, and whole grains, contain fiber, vitamins, and minerals, each has a unique nutritional profile and offers distinct health benefits.
Fruits and Vegetables
For example, most fruits are high in natural sugars, which provide a quick source of energy. Fruits like watermelon, pineapple, and citrus fruits also have a high water content, making them a good source of hydration.
Fruits and vegetables contain high levels of antioxidants, compounds that help protect cells against oxidative damage. Studies show that diets high in anthocyanins may help protect against common health conditions like heart disease. Some fruits and vegetables are also high in vitamin C, an antioxidant vitamin that plays important roles in skin and immune health.
Grains and Legumes
Grains and legumes provide fiber-rich complex carbohydrates, which serve as a steady source of energy. Choosing fiber-rich carbohydrates may help support healthy blood sugar and blood lipid levels. Whole grains and legumes can also help promote fullness and satisfaction after meals. In addition, these foods are often rich in important nutrients such as magnesium.
Legumes, like lentils, stand out from many other carbohydrate-rich foods because they’re also high in protein. Protein helps keep you full and satisfied after eating and is essential for muscle growth, hormone production, and many other important processes in the body.
Why Variety Matters
Including a variety of fiber sources in your diet ensures that you’re providing your body with the nutrients it needs.
Consuming a diet high in both insoluble and soluble fiber promotes and protects gut health by stimulating the growth of beneficial gut bacteria, reducing the risk of constipation, and keeping bowel movements regular and comfortable.
Additionally, different types of fibers nourish different types of gut bacteria. For example, inulin, a type of fiber found in foods like onions and garlic, stimulates the growth of beneficial Bifidobacterium and Lactobacillus species, while pectin, concentrated in apples and pears, fuels Faecalibacterium prausnitzii, a bacterium that produces anti-inflammatory molecules in the gut.
Soluble and insoluble fibers play essential roles in the body, and incorporating a variety of fiber-rich foods into your daily diet can help you meet your daily fiber and nutrient goals.
Are Fiber Supplements and Fiber-Added Foods Enough?
Fiber supplements, like psyllium husk, can be helpful for certain people, especially those with conditions like high cholesterol or constipation. However, fiber supplements usually contain one type of fiber.
Studies show that psyllium husk, a source of soluble fiber, may help reduce constipation symptoms, support a healthy balance of gut bacteria, and promote healthy cholesterol and blood sugar levels. Plus, fiber supplements, like psyllium husk, are relatively affordable and easy to use, which makes them a convenient way for people to increase their fiber intake.
Fortified bars, cereals, and other high-fiber products can help you meet your fiber goals and address issues like constipation, but they shouldn’t completely replace whole-food sources of fiber.
Whole food sources of fiber, like fruits, vegetables, beans, nuts, and whole grains, provide fiber alongside other nutrients that support overall health. While supplements and fiber-fortified foods can be useful tools, getting most of your fiber from a variety of whole plant foods is generally the best long-term approach for supporting overall health.
Simple Ways to Eat More Fiber From Different Sources
If you’re looking for simple ways to add more fiber to your diet, try these expert-approved tips:
- Swap refined grains, like white rice and white bread, for whole grains or legumes
- Add beans to soups, salads, rice dishes, and meat sauces for a boost of fiber
- Add a side of sliced fruit to your breakfast and lunch
- Snack on balanced, fiber-rich options, like a piece of fresh fruit paired with a handful of nuts and seeds
- Add chia seeds, almonds, and berries to your morning yogurt
- Swap sugary cereals for oatmeal or chia pudding
- Add veggies and beans to your pasta dishes
If your diet is currently low in fiber, it’s best to increase your fiber intake gradually to give your body time to adjust and help reduce the risk of side effects like bloating and gas.
