Too Much Fiber: Signs and Symptoms

Dietary fiber, which comes from plant foods, is associated with many health benefits, from lowering the risk of heart disease to keeping blood sugar stable and improving gut health. Usually, adding more fiber to your diet is a good idea, since many processed foods in the American diet are devoid of enough fiber content. In fact, an estimated 95% of American adults and children do not consume recommended amounts of fiber.

However, consuming too much also comes with some risks. Dietary fiber comes from certain carbohydrates in plant foods that can’t be absorbed by your body. It comes in two categories-soluble and insoluble fiber. Soluble fiber dissolves in water, forms a gel in your intestines, and helps the food move through your gastrointestinal system smoothly. Insoluble fiber bulks up stool and makes it softer and easier to pass.

Both types of fiber can be helpful for improving your health. However, not everyone does well with high-fiber diet. In addition, too much fiber can lead to certain health risks. If you increase your fiber intake too much or too soon, you could experience some uncomfortable or even serious side effects.

Keep reading to learn what eating too much fiber can do to your body and how much is actually recommended.

The most common side effect you may experience from eating too much fiber is gastrointestinal discomfort such as gas and bloating. When you eat foods high in fiber, and especially when you first increase the fiber in your diet, you can experience a bloated, distended stomach and gas, diarrhea, or flatulence.

This can happen if you eat a large amount of fiber at one meal, or if you increase your fiber intake too quickly. Usually, this side effect improves after the gut bacteria in your body gets used to the extra fiber.

Eating too much fiber can interfere with the absorption of several important minerals, like calcium, iron, magnesium, and zinc. This happens because fiber acts as a binding agent, which can keep some of the minerals in the foods you eat from being absorbed by your body.

Many high-fiber foods are also high in minerals, so most people will not have a problem with this. But for some, a mineral deficiency may be a possibility. Including foods high in those particular minerals, like meat, may provide your body with enough extra minerals to offset the problem.

In theory, eating fiber should help to relieve constipation, but unfortunately, this doesn’t work for everyone. In some cases, fiber can make constipation worse. Some studies show that adding fiber to your diet may improve the symptoms of constipation, but other studies show that reducing your intake is best.

Some other studies have also shown that people with chronic constipation eat similar amounts of fiber as people who don’t have constipation. Therefore, if your constipation is caused by something else that is not a lack of fiber, (such as taking certain medications, having irritable bowel syndrome (IBS), or being dehydrated) consuming more fiber would not help, and could even make your condition worse.

While rare, consuming too much fiber can cause an bowel obstruction where undigested fibers or fecal matter gets stuck in a narrow part of your intestines, causing pain and the urgent need for medical attention.

Undigested fiber from fruits or vegetables can form a hard, solid mass that blocks anything from getting through the intestines. This is more likely to happen in older adults who do not chew their food thoroughly. Intestinal blockage is serious and may require surgery. 

There is no set an upper limit on fiber intake, which means there isn’t an amount that’s considered bad for you. The amount of fiber you should consume daily mostly depends on your age and sex, but also your own individual fiber needs and tolerance. The average recommended amount may not work for everyone.

The U.S. Dietary Guidelines recommend 14 grams of fiber per 1,000 calories of food. For the average adult, that comes out to about 28 grams of fiber a day, split between all meals and snacks.

However, that is just an average and it’s a good idea to experiment with different amounts of fiber until you find what works for you.

Women

According to the recommended guidelines, the average adult woman needs about 25 grams of fiber per day. Your needs may differ depending on your particular situation, your size, and your age. After age 50, it is recommended to get at least 21 grams daily.

Men

The average adult man needs about 38 grams of fiber per day. Depending on your individual need, your size, and age, your needs may differ. After age 50, it is recommended to get at least 30 grams daily.

Children

Children and teens are a tricky group because their size and age vary a lot. Official recommendations for older children and teenagers is between 21 and 38 grams of fiber per day.

This amount may be difficult to achieve, since some children and teens eat smaller amounts of food. One way to help that age group increase their fiber intake is to focus on high-fiber foods, like nuts, beans, whole grains, fruits, and vegetables. 

If you find that you are regularly experiencing uncomfortable gastrointestinal symptoms like gas, bloating, diarrhea, or constipation, it’s wise to speak with your healthcare provider.

If you have trouble adjusting the amount of fiber in your diet to a balance that seems to work for you, your healthcare provider can help you figure out how much fiber to add to your diet, and give you ideas of what foods to add or take away.

If you have a history of intestinal problems, like an injury, celiac disease, prior bowel obstruction, diverticulitis, or any absorption disorder, a gastroenterologist can help you find a good balance of fiber in your diet. Gastroenterologists are medical doctors who specialize in the health of your gastrointestinal system.

Most people in the U.S. don’t consume enough fiber, so usually, adding more fiber to your diet can be a good idea. However, the type of fiber and the frequency in which you consume it matters.

If you increase your fiber intake too much or too soon, you could experience some uncomfortable or even serious side effects such as gas and bloating, constipation, and mineral deficiencies.

Speak to your healthcare provider if you’re considering increasing your fiber intake.