You know you’re supposed to eat plenty of fiber (28-34 grams per day, per the 2020-2025 Dietary Guidelines for Americans), but if you’re among the 90-97% of Americans not getting enough of it in your diet, you’re missing out on a slew of health benefits. Here are 10 of fiber’s health benefits to encourage you to get your fill.
1. HEALTHY WEIGHT LOSS
It is well-known increasing your dietary fiber intake may help in your weight loss journey. In a 2019 randomized controlled trial published inThe Journal of Nutrition, participants were assigned to one of four different calorie-restricted groups. They were also instructed to increase their dietary fiber intake at various intervals and to include 90 minutes of physical activity each week. Results showed that regardless of diet type, participants lost about the same amount of weight. Study authors felt this was due to the fiber intake and not calorie consumption, which affirms what previous studies had shown—that increasing your fiber intake can help you lose weight.
Fiber-rich foods fill you up faster and keep you satisfied longer.
2. WEIGHT CONTROL
While more research needs to be performed, there is some evidence that suggests that those who eat more fiber tend to be leaner, according to a 2023 study in Frontiers in Nutrition. Researchers found that people who ate the most fiber after losing weight weighed less than those who ate less dietary fiber.
3. LOWER TYPE 2 DIABETES RISK
A 2020 study published in the Journal of Diabetes Investigation found that a higher overall intake of dietary fiber was associated with a lower risk of type 2 diabetes. And while some previous studies showed that insoluble fiber was best type of fiber for lowering type 2 diabetes risk, this study suggests that the combination of soluble and insoluble fiber predicted greater prevention of type 2 diabetes. While it’s not totally clear why fiber cuts type 2 diabetes risk, the researchers believe that it could be a combination of fiber’s favorable effect on blood glucose levels, creating a healthier gut microbiome and lowering inflammation in the body that may help stave off the development of diabetes.
4. LOWER ODDS OF HEART DISEASE
According to a 2022 BMC Public Health study, a higher fiber intake was associated with a reduced risk for cardiovascular disease (CVD) in a large group of Americans. Researchers don’t completely understand how fiber works, but they think that soluble fiber plays a role in decreasing lipid uptake from the intestinal tract, resulting in lower blood levels of cholesterol according to a 2023 Advances in Nutrition review. In addition, experts say that dietary fiber reduces inflammation which can result in CVD in a 2022 JAMA Network Open article.
5. INCREASED BENEFICIAL GUT BACTERIA
The good bacteria that make up your gut’s microbiome feed off fiber which helps them flourish. According to a 2022 review article in Animal Nutrition, as your gut bacteria gobble up fiber that has fermented in your GI tract, they produce short-chain fatty acids that have a host of benefits—including lowering systemic inflammation, which has been linked to many chronic health problems.
When you increase your fiber intake, it doesn’t take long to see the results. “You can start to see the changes in gut bacteria within just a few days,” says Kelly Swanson, Ph.D., a professor of nutritional sciences at the University of Illinois at Urbana-Champaign. The catch: You’ve got to consistently get enough grams of fiber over time to keep getting the benefits. Skimping on fiber shifts bacteria populations that may have negative consequences and result in increased inflammation in the body.
6. REDUCED RISK OF CERTAIN CANCERS
While studies are mixed, most seem to point to higher fiber consumption lowering the risk of cancer, especially colorectal and breast cancers. For example, in a 2020 review in The American Journal of Clinical Nutrition, researchers found that higher fiber intake, in particular, the fiber found in whole grains, was correlated with a reduced risk of colorectal cancer. And another 2020 review published in Cancer found that soluble fiber and fruit fiber had the strongest associations with reduced risk of breast cancer.
This falls in line with the American Cancer Society’s recommendations to eat foods rich in total fiber, which include fruits, vegetables and whole grains.
7. LONGER LIFE
A 2022 review in the Journal of Translational Medicine found that people who ate enough total fiber—which includes soluble and insoluble fibers—had a lower chance of dying early from anything, including cardiovascular disease and cancer. This means that even if you were to get heart disease, cancer or another condition, consuming enough fiber may protect you from dying from it.
8. MORE REGULAR BOWEL MOVEMENTS
“Constipation is one of the most common GI complaints in the United States,” says Tanya Zuckerbrot, RD, author of The F-Factor Diet. If you find yourself constipated, fiber might help. Fiber makes your poop softer and bulkier—both of which speed its passage from your body. But different types of fiber may provide varying levels of success in your quest for more regular bowel movements. A 2020 review in the Journal of the American Association of Nurse Practitioners suggests that psyllium fiber beats out other types of fiber for those with chronic idiopathic constipation, which is characterized by difficult, infrequent or incomplete bowel movements. Other studies, like the 2021 review in Clinical and Experimental Gastroenterology note that including plenty of water with your high-fiber diet also helps move things along in your gut better than fiber alone.
9. ALL-NATURAL DETOX
Forget the trendy juice cleanse fads. Fiber naturally scrubs and promotes the elimination of toxins from your GI tract. “Soluble fiber soaks up potentially harmful compounds, such as excess estrogen and unhealthy fats, before they can be absorbed by the body,” explains Zuckerbrot. And because insoluble fiber makes things move along more quickly, it limits the amount of time that chemicals like BPA, mercury and pesticides stay in your system, adds Zuckerbrot. The faster they go through you, the less chance they have to cause harm.
10. STRONG BONES
Some types of soluble fiber—known as prebiotics—have been shown to contribute to a greater bioavailability of minerals, like calcium, in your colon. The increase in bioavailability supports maintain bone density, according to a 2018 review in the journal Calcified Tissue International. Prebiotics provide food for your beneficial gut bacteria and can be found in certain fruits, vegetables, nuts and whole grains, such as asparagus, bananas, walnuts, onions, legumes, wheat and oats.
THE BOTTOM LINE
As you can see, fiber—all types—is good for your health. By eating a well-rounded, balanced diet that includes plenty of fruit, vegetables, nuts, seeds, legumes and whole grains, you will likely get the amount of fiber your body needs to run efficiently and lower your disease risk.