The Harms of Too Much Fiber

Excess fiber can lead to bloating and abdominal discomfort.
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Fiber: You need it to maintain digestive regularity, but too much too soon can make you feel pretty uncomfortable thanks to excess gas buildup in your digestive tract. Excess fiber also can affect your body’s ability to absorb key nutrients. These factors mean fiber intake is all about timing and quantity.

Your Fiber Intake

Dietary fiber is a component of many healthy foods, including fruits, vegetables and whole grains. Also known as roughage or bulk, dietary fiber remains largely undigested in your body. Instead of being broken down completely and absorbed, fiber travels through your intestines and takes in water. This makes your stool larger, which stimulates your intestines to keep pushing your stool out the body. You need about 25 grams of fiber each day.

Affected Absorption

When you take in too much fiber, your body cannot properly absorb nutrients. This includes minerals such as iron, zinc, magnesium and calcium. Insoluble fiber sources, such as whole wheat, are more likely to affect mineral absorption than foods rich in soluble fiber, such as seeds and beans. Because many high-fiber foods also are high in minerals, their affected absorption may not impact your overall nutrient intake.

Abdominal Discomfort

If you have resolved to start eating more fiber, don’t do it all in one sitting. Your body has to adjust to the added fiber in your diet. Taking in too much fiber at a time can result in bloating, abdominal cramping and flatulence. Bacteria in your digestive tract are not accustomed to breaking down the added material in the fiber. As a result, the by-product of their activity is excess gas. This is true not only if you overeat fiber-rich foods, but also if you take excess fiber supplements.


You don’t have to experience the harms associated with excess fiber intake. If possible, try to space your fiber supplements or fiber intake over the course of the day and drink plenty of water to help your body better process the extra fiber. Add an extra fiber serving each day, such as raw vegetables, whole-grain breads, nuts, fruits or high-fiber cereal. If you eat the extra serving and experience no adverse side effects, you can add another serving until you reach your recommended daily intake.

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