Fiber is an essential component of a balanced diet, given its protective effects against obesity, diabetes, and gastrointestinal and cardiovascular diseases.1 Found mainly in plants, dietary fiber consists of indigestible carbohydrates and a plant polymer called lignin.1,2
It is well-known that consumption of fiber improves bowel movements and gastrointestinal motility, which can ease constipation. Certain types of fiber can delay gastric emptying and give a feeling of fullness after a meal, which can help with weight control. This delay in emptying ingested food into the small intestine may also reduce blood glucose concentrations and positively affect insulin sensitivity. Fiber can also interfere with the absorption of dietary fat and cholesterol, which can reduce blood cholesterol concentrations.2
You can get plenty of fiber from cereal grains and beans, but not if you have to avoid these foods due to intolerance or allergies. Luckily, there are other foods you can eat to get your recommended daily amount of dietary fiber (38 grams for men and 25 grams for women2).
For instance, there are a number of fresh fruits and vegetables that contain high levels of fiber. Some of the most fiber-rich fruits and vegetables are as follows.
Passion fruit. This small, seed-filled tropical fruit packs a fiber punch. A 100-gram portion of passion fruit contains 10.4 grams of fiber, while a one-cup serving has a whopping 24.5 grams.3 That means one cup of passion fruit has 98% of the daily amount of fiber recommended for women and 66% of the recommended daily amount for men.
Avocado. Although the avocado is often used the way a vegetable would be, it is botanically classified as a fruit.4 There are about 6.7 grams of fiber in 100 grams of avocado.3 But how much fiber there is in a cup of avocado depends on the way it’s prepared. For instance, one cup of pureed avocado contains about 15.4 grams of fiber, while a cup of sliced avocado contains roughly 9.8 grams of fiber.3
Raspberry. When consumed raw, seed-filled raspberries are an excellent source of fiber. There are 6.5 grams of fiber in 100 grams of raspberries and 8 grams in one cup.3
Guava. The tropical guava is often used in juices and other drinks, but it can be eaten whole as well.5 One hundred grams of guava contains 5.4 grams of fiber, and there are 8.9 grams in one cup.3
Blackberry. Like raspberries, blackberries contain a fair number of seeds when eaten raw. A 100-gram serving of blackberries has 5.3 grams of fiber, while one cup contains 7.6 grams.3
Pomegranate. Native to the Middle East, the pomegranate fruit is composed of a tough skin that surrounds sacs filled with edible seeds.6 There are 4 grams of fiber in 100 grams of pomegranate, and 7 grams in a cup.3
Persimmon. The persimmon tree is native to China and bears edible fruit.7 A 100-gram portion of raw persimmon contains 3.6 grams of fiber.3
Kiwifruit. Although kiwifruit is now grown in many countries, most notably New Zealand, it actually originated in China.8 There are 3 grams of fiber in 100 grams of kiwifruit, and 5.4 grams in one cup of sliced kiwifruit.3
Pear. In addition to potassium and vitamin C, pears contain a good amount of fiber.9 A 100-gram portion of pear contains 3.1 grams of fiber, and one cup of pear slices contains 4.65 grams of fiber.3
Orange. While the orange is best known as a source of vitamin C, it also provides a fiber boost. There are 2.4 grams of fiber in a 100-gram portion of orange, and 4.3 grams in one cup of orange segments.3
Lima beans. Named for the city in Peru, Lima beans are usually sold in dried, frozen, or canned form in the United States, although they are available fresh in some southern U.S. states.10 When cooked, one cup of lima beans has 9.2 grams of fiber.3
Acorn squash. A winter squash that is indigenous to North and Central America, acorn squash is often roasted or steamed before eating.11 One cup of cubed, baked acorn squash contains 9 grams of fiber, while a cup of mashed acorn squash has 6.4 grams of fiber.3
Green peas. Thought to be native to Middle Asia and Ethiopia, peas are rich in fiber as well as vitamins A and C, folate, iron, and thiamine.12 A one-cup serving of cooked peas contains 8.8 grams of fiber.3
Collard Greens. This dark leafy green vegetable is native to the Mediterranean13 and is usually cooked before eating, although it can be eaten raw. One cup of chopped, cooked collard greens contains 7.6 grams of fiber.3
Artichoke. Once the hairy center is removed, the fleshy base of the artichoke is edible, as are the bases of its leaves.14 There are 7.7 grams of fiber in one cup of cooked artichoke.3
Butternut squash. A winter squash native to North America, butternut squash can be steamed or roasted before eating.11 One cup of cooked, cubed butternut squash has 6.6 grams of fiber.3
Parsnip. The parsnip is native to Europe and Asia and was introduced to North America in the 17th century.15 Usually, parsnips are cooked before they’re eaten, and one cup of sliced, cooked parsnips contain 5.6 grams of fiber.3
Broccoli. Broccoli can be steamed or roasted, or it can be eaten raw. A cup of cooked broccoli has 5.1 grams of fiber3 because cooking and chopping broccoli results in a more concentrated amount of the vegetable. By contrast, a cup of raw broccoli florets contains 1.6 grams of fiber.3
Carrot. As with broccoli, carrots can either be consumed raw or cooked. There are 3.4 grams of fiber in one cup of raw carrot strips or slices, and 4.7 grams in a cup of cooked carrot slices.3
Spinach. There is a tremendous difference in the volume of raw spinach versus cooked spinach. Once cooked, spinach tends to shrink as the moisture it contains evaporates. One cup of raw spinach leaves has only 0.7 grams of fiber, while a cup of cooked spinach contains 4.3 grams of fiber.3
So, when you’re looking for a quick, grain-free fiber boost, reach for the fruit bowl or put some vegetables on your plate. Both are delicious ways to ensure you maintain a fiber-rich diet.