What Happens to Your Body When You Eat Too Much Fiber

Fiber is a type of carbohydrate that the body doesn't digest or absorb and is found exclusively in plant foods such as fruits, vegetables, nuts, seeds and whole grains. It is a nutrient that's important for health. It helps regulate digestion, manage cholesterol and stabilize blood sugars.

There are two types of fiber: soluble and insoluble. Soluble fiber, when mixed with liquid, forms a gel-like substance that's important for good digestive health. It also helps reduce LDL cholesterol levels—the "bad" type of cholesterol. Soluble fiber binds to this cholesterol and helps ferry it out of the body. Some sources of soluble fiber are bananas, apples, oats, berries and avocados. Insoluble fiber, on the other hand, does not attract liquids. It helps manage constipation by adding bulk to the stool and moving things along. It also promotes insulin sensitivity. Some sources of insoluble fiber are nuts, seeds, corn, whole-wheat flour and the skins of many fruits and vegetables. It is possible to have too much of a good thing. We'll talk about what fiber is, recommendations for fiber intake, what happens if you eat too much fiber and what to do if you overdo it.

Health Effects of Eating Too Much Fiber

You May Experience Gas and Bloating

The CDC recommends eating 22 to 34 grams of fiber per day, depending on age and sex. "Everyone's tolerance to fiber will vary, so even the recommended daily amount may be too much if you haven't regularly been including fiber-rich foods in your diet," says Samina Qureshi, RDN, founder of a virtual nutrition practice that specializes in digestive health.

Over 90% of Americans do not consume enough fiber. However, if you increase your fiber intake too quickly, it can cause uncomfortable gastrointestinal effects, including gas and bloating. If you're trying to increase your fiber intake, do so slowly. You can try adding a few grams of fiber per week.

You May Not Consume Enough Calories

Fiber helps add volume to meals, which can help promote satiety. However, foods that contain fiber, such as vegetables, fruits, beans and lentils, also tend to be lower in calories. If you rely too heavily on fiber, you may end up feeling too full to eat other foods. "If you eat too much fiber without leaving room for other macronutrients, it can interfere with your ability to meet all your nutritional needs (fat, protein and micronutrients)," Qureshi says.

While many people worry about overeating, undereating has real consequences, especially when chronic. Ultimately, eating well-rounded meals that contain a balance of carbohydrates, protein, fat and fiber will help you feel your best.

You May Become Constipated

Overdoing fiber could lead to constipation for a variety of reasons. "Oftentimes people will hear that they need to eat more fiber if they are constipated, but it needs to be done in a slow and steady way while also increasing your hydration to avoid making constipation worse," says Qureshi.

Constipation brings with it all kinds of symptoms, from gas and bloating to abdominal pain and temporary weight gain. Because fiber absorbs water from the intestines, make sure you're drinking an adequate amount of water to keep things moving through your gut.

You May Develop a Bowel Obstruction

This is rare, but some people may develop a blockage in their intestinal tract, called a phytobezoar, if they consume too much fiber. This happens when fiber builds up in the intestine and forms a ball that blocks things from passing through. Elderly people or those with certain digestive diseases may be at higher risk due to reduced digestive efficiency and reduced elasticity of the intestinal wall. Inadequate chewing could also contribute. If you experience symptoms such as nausea, vomiting, fever, severe abdominal pain or an inability to pass gas or stool, see a doctor immediately.

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Daily Fiber Recommendations

Daily fiber recommendations vary based on your age and sex. The recommendations for daily fiber intake are: