Do you think you’re eating enough fiber? Think again. Adults should eat 14 grams of fiber per 1,000 calories consumed. That’s 28 to 34 grams of fiber per day for most men. However, most eat less than half, according to the Dietary Guidelines for Americans 2020-2025.
Why so little? Bad food choices are to blame, says Dr. Walter Willet, professor of epidemiology and nutrition at Harvard’s TH Chan School of Public Health. “People are eating more ready-to-eat processed foods, made from refined grains that lack fiber, such as white rice and white flour and found in pastas, pastries, cakes and crackers. “
Changes in eating habits also play a role. As people age, they often need fewer calories. Eating less further reduces their fiber intake. Additionally, many high-fiber foods require more chewing than other foods, which can be difficult for some older adults.
Both types
There are two types of fiber: soluble and insoluble. Soluble fiber draws water from the stomach, turning it into a gel. This slows down digestion and makes you feel full after eating. It also helps soften stools. In comparison, insoluble fiber does not dissolve in water. It adds necessary volume to stools, thereby preventing constipation.
But fiber has other health benefits. Research has shown that a high-fiber diet reduces LDL (bad) cholesterol levels and is associated with a lower incidence of cardiovascular disease, cancer and diabetes.
Studies have also found that adequate fiber can also change the gut microbiome to support the immune system and protect against inflammation. High levels of dietary fiber may also help reduce the risk of developing dementia, according to a 2023 study published in Nutritional neuroscience.
Find the fiber
There are many high-fiber foods to choose from, so chances are you’ll find several to add to your diet. Examples include fruits, vegetables, legumes, nuts, seeds and whole grains. (You can find a list of high fiber foods at /fiber.)
Men can get the daily fiber they need by eating two to four servings of fruit; two to five servings of vegetables, whole grains or legumes; and one to two servings of nuts and seeds. But don’t get bogged down in tracking exact amounts of fiber for each meal or worry about eating enough of both types of fiber. “Keep it simple and just focus on eating a variety of fiber-rich foods and avoiding refined grains,” says Dr. Willett. However, you can start by eating just one or two of your favorite fiber-rich foods. “If you like blueberries, eat two servings daily,” says Dr. Willett. “Gradually, you can add other fiber-rich foods.”
The role of supplementsOver-the-counter fiber supplements come in capsules, powders to mix with water, and chewable tablets. Common brands include Benefiber, Metamucil, Citrucel, and Konsyl. Are they still a good option? If you have trouble eating high-fiber foods – due to a food sensitivity or difficulty chewing high-fiber foods – these can occasionally be used to increase your fiber intake, according to Dr. Walter Willett of Harvard’s TH Chan of Public Health. “Some people may also benefit from a supplement if they have constipation due to medications or are on a low-carb diet for health reasons,” he explains. “However, supplements should never replace a healthy diet as your primary source of fiber, because they do not provide the valuable micronutrients you get from fiber-rich foods.” If you think you might benefit from a fiber supplement, talk to your doctor. |
Small changes
Another approach is to make small changes to your eating habits. For example, commit to eating beans, lentils or peas at least three times a week. Replace regular pasta with versions made from whole wheat, quinoa, chickpeas or lentils.
Replace white rice with whole grains like brown rice or bulgur. “Something simple, like starting your day with a bowl of steel-cut oatmeal, is also a good start,” says Dr. Willett. “I top mine with yogurt, nuts and seasonal fruit, which adds variety and more fiber.”
Watch out for too much fiber during a run to increase your daily intake. “Your digestive system can’t always tolerate a lot of fiber at one time, which can lead to gas, bloating, diarrhea, and stomach cramps,” says Dr. Willett. “Take it slow and make sure you drink plenty of water daily as you increase your fiber intake.”
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