How Much Fiber Do Men Need and Where Can They Find It?
Key Points
- Fiber promotes healthy digestion and reduces the risk of certain diseases and cancers.
- Men should aim for 14 grams of dietary fiber per 1,000 calories consumed.
- Foods such as fruits, vegetables and lentils are good sources of fiber.
You probably don't know all the facts about nutrition––and that's OK. When it comes to men's fiber needs, you might wonder: Is bread high in fiber? Are grain breads higher in fiber? Which foods are good fiber sources? How much fiber do men need?
Why does fiber matter?
Fiber is key to men's health. It promotes healthy digestion and reduces the risk of chronic diseases, such as esophageal cancer, a 2007 study suggested.
If you struggle with your weight, fiber can help there, too. Fiber helps maintain a healthy weight, which lowers cholesterol levels and regulates blood sugar.
This is essential to preventing heart disease and diabetes, said Kelsey Costa, R.D.N., a health researcher and consultant for the National Coalition on Healthcare (NCHC).
Fiber's ability to aid in digestion helps keep the gut microbiome strong, which contributes to men's overall health.
"Evidence continues to emerge on how our gut is not only connected to our brain but just about all other body systems," said Cesar Sauza, R.D.N., a clinical dietician, nutrition manager and consultant for the NCHC. "Dysbiosis, or an unbalanced gut microbiome, can wreak havoc on the body."
Is one type of fiber better than another?
There are two different types of fiber: insoluble and soluble.
"The main difference between the two types of fiber lies in their function in the body," said Melissa Snover, a registered nutritionist and the founder of Nourished, a nutritional supplement manufacturer in West Midlands, England. "Both types of fiber are important for maintaining overall health."
Insoluble fiber, found in whole grains, nuts and seeds, aids digestive health by preventing constipation and promoting regular bowel movements, according to Snover.
Soluble fibers help to regulate blood sugar levels, lower cholesterol and promote the growth of beneficial gut bacteria. Soluble fiber is found in oatmeal, fruits and vegetables. It dissolves in water, turning into a gel-like substance in the digestive system, she added.
How many grams of fiber do you need a day as a man?
Men should aim for 14 grams of dietary fiber for every 1,000 calories consumed, according to the U.S. Department of Agriculture's Dietary Guidelines for Americans.
"I like using this guideline with my patients because it takes into consideration the total calories consumed," said Mary Pardee, N.D., a naturopathic doctor and functional medicine doctor at Modrn Med in Sherman Oaks, California.
Men should consume between 28 and 34 grams of fiber a day, depending on their age. Men older than 52 should get 28 grams of daily fiber; men between ages 31 and 50 should aim for 30.8 grams; and men between 19 and 30 should strive for 33.6 grams of fiber a day, according to the Dietary Guidelines for Americans.
"Research suggests that the fiber intake guidelines listed may only represent a baseline. Men could experience additional health benefits by consuming 50 grams or more of dietary fiber daily," Costa said.
"The argument could be made that the recommended daily amounts of fiber for men should be closer to 50 grams per day since many studies have shown increased benefits with higher levels of fiber," Sauza said.
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What does 30 grams of fiber look like?
"Most individuals are not reaching anywhere near the recommended amount of fiber, and it tends to be even less in men," Sauza said. "Men usually require more fiber than women if their caloric requirements are higher, but generally speaking, recommended fiber intake should be based on weight (if at a healthy weight)."
Thirty grams of fiber a day in food could look like this:
- 1/2 cup lentils = 8 grams of fiber
- 1 cup butternut squash = 7 of grams fiber
- 1 cup frozen spinach, cooked = 7 grams of fiber
- 1 cup raspberries = 8 grams of fiber
How long does fiber take to work?
The effects of increased fiber intake for men vary from person to person. Enhanced digestion and constipation relief usually occur within a few days to a week, Costa said.
"If you are using soluble fiber sources to help with constipation, then you want to give it at least three days of consistently taking it to start to see effects," Pardee said. "Some people are more sensitive to fiber than others, and they will need to increase fiber intake more gradually to avoid side effects like bloating or gas."
Increasing dietary fiber intake for individuals with chronic constipation took up to four weeks to help with the issue, a 2022 study suggested.
Fiber's benefits—reduced cholesterol, blood sugar regulation, a decreased risk of chronic diseases, such as heart disease and diabetes—are long-term.
"These benefits typically become apparent after several weeks, months or even years of consistent high fiber intake. This is largely contingent on sustained healthy dietary habits and lifestyle patterns," Costa said.
What happens if you have too much fiber?
The answer to how much fiber is too much isn't clear-cut. Consuming 70 grams or more of fiber a day is generally considered too much. This extra fiber can absorb water and swell, which will slow down digestion due to not enough hydration, Costa said.
"Excess fiber is more likely to cause bloating or gas than constipation, although it is possible that diarrhea is more likely with eating too much fiber," Sauza said. "Fiber should help improve the gut to limit these symptoms; however, fiber may cause discomfort in those [individuals] that had a fiber-less diet."
Adding more fiber gradually in 5-gram intervals on a weekly or biweekly basis, eventually working up to 30 to 40 grams, depending on the individual, should help prevent these symptoms. It could take up to six weeks to reach the individual's recommended fiber intake, Sauza added.
Bloating
Fiber can cause bloating since soluble fiber can hold onto a lot of water that bulks in the stool. However, bulk in the digestive tract is what leads to the feeling of bloating. Certain types of fiber, such as bran, are more likely to cause bloating.
Psyllium husk is typically better tolerated in the digestive system and could lead to less bloating, Pardee said.
Gas
Fiber can cause gas because fiber is broken down by the bacteria in the digestive tract. When bacteria break down dietary fiber, gasses such as methane and hydrogen are produced, which is a source of bodily gas, according to Pardee.
Gas from fiber is usually caused by not drinking enough water with your high-fiber foods. Stay hydrated when increasing your fiber intake to decrease your gas, said Rebecca Fallihee, C.N.S., a licensed dietitian at GUTSy Performance Nutrition in Eugene, Oregon.
Constipation
When you dramatically increase your fiber intake from a little to a lot, gut microbes feed on some of this fiber, causing an abrupt shift in the diet. This can cause a change in the microbial populations in the gut, which can cause some to grow and others to die, Fallihee said.
This shift can cause uncomfortable GI symptoms, such as constipation. This is more likely to happen if the person isn't hydrated enough. Again, make sure you drink plenty of water when increasing your fiber intake to reduce the chances of constipation.
"The key here is to make dietary shifts slowly and gradually to allow for a more gradual shift in the gut microbial population," she said.
What are the health benefits of fiber?
Fiber is vital to bringing and maintaining varieties of bacteria for gut health and can help with maintaining a healthy weight, said Ana Bueno, a certified plant-based nutrition coach with BuenoSeeds Nutrition with locations in Colorado and Florida.
Feel full
"Fiber is a high-satiating carbohydrate that our body cannot break down. Fiber helps slow down digestion, which helps prevent hunger for longer," Sauza said.
The release of acetate from fiber-rich foods can suppress the appetite and reduce overeating tendencies by triggering chemical reactions to efficiently suppress hunger signals when absorbed by the bloodstream, brain or colon, a 2014 study indicated.
Bodily health
Fiber's ability to improve the variety and health of gut bacteria strengthens the immune system, which helps prevent disease, Bueno said. People who consumed enough soluble and insoluble fibers lowered their risk of dying from health conditions such as cardiovascular disease and cancer, according to a 2022 study.
Fiber plays another important role. It helps regulate the body's use of sugars, which helps keep blood sugar levels in check. Fiber supports overall health by reducing LDL cholesterol (aka "bad cholesterol") levels, maintaining bowel health, and decreasing the risk of heart disease and other chronic illnesses, Costa said.
Promote bowel health
"Fiber helps improve digestion by adding bulk to stools, but also helps push stools along," Sauza said.
However, that only works with enough hydration. Drink lots of water.
"For fiber to work, you have to hydrate it in your body," Bueno said.
Fiber's ability to aid in a quicker and smoother passage of food through the digestive tract reduces the likelihood of constipation.
"Certain types of fiber serve as prebiotics, nourishing the beneficial gut bacteria … promoting a healthy gut microbiome for improved digestive health and overall wellness," Costa said.
Should I take fiber supplements?
Fiber supplements may provide quick relief from constipation, but relying too much on this supplement for regular bowel movements isn't good. That's especially true if you forget to eat fiber-rich foods that provide the body with other essential vitamins and minerals, Bueno said.
For people with diabetes and certain other health conditions, fiber supplements such as Metamucil can be helpful if you are on an extremely restrictive diet. The best way to get fiber content to sustain your health for the long term is with a food-first approach. The body responds better to whole foods rather than an isolated part of the food, such as fiber pills, Fallihee said.
Does fiber have calories?
Fiber itself does not have calories because it is not digested or absorbed by humans. We do not have the enzymes to digest fiber. Bacteria in our gut are able to ferment certain foods and break them down so we can digest, absorb and benefit from high-fiber meals, Pardee said.
"The FDA estimates that fermented fibers provide about two calories per gram," Bueno said. "On the other hand, insoluble fibers remain mainly unchanged as they travel to the intestine. They do not get digested. They increase bulk, soften stool and reduce the time it takes for food to move through the digestive system. The FDA estimates insoluble fibers do not contribute any calories."
You may want to skip the calorie counting. Fiber is a little different.
"I often recommend individuals don't get too caught up in counting or tracking calories and instead tune into their hunger and fullness levels and how they feel following meals eating more intuitively," Fallihee said.
Can too much fiber cause hemorrhoids?
Fiber does not cause hemorrhoids. A diet too low in fiber is actually a possible cause of developing hemorrhoids. Hemorrhoids are often managed by increasing dietary fiber and drinking plenty of water, Bueno said.
Eating enough high-fiber food can make your stools softer and easier to pass, which can help treat and prevent hemorrhoids, according to a 2016 report from the National Institute of Diabetes and Digestive and Kidney Diseases.
"Soluble fiber helps to bulk the stool and soften it, which is needed in the treatment of hemorrhoids. Fiber has also been found to help reduce hemorrhoid bleeding and mild prolapse," Pardee said. "Treating constipation is essential in the treatment of hemorrhoids and the prevention of hemorrhoids, and a diet that is rich in fiber can help with this."
The bottom line
Fiber is a key nutrient men's bodies need. It can aid with digestion and help prevent hemorrhoids and chronic diseases.
Start gradually adding more fiber to your diet and drink plenty of water to avoid gas, bloating and constipation.
