Too much fiber can cause diarrhea and excessive bowel movements, making the body excrete too many vitamins and minerals. The loss of water and nutrients such as calcium, iron, magnesium and zinc can result in malnutrition and dehydration. In addition, too much fiber can cause stomach cramping and a bloated abdomen from the buildup of internal gas. Dieticians recommend that individuals consume only 15 to 30 grams of fiber daily. More than 50 grams is considered too much fiber by most dieticians.
Fiber, which is only found in plant foods or supplements made from plants, comes from vegetables, grains, beans, and fruits — especially those consumed with the skin on. Both types of fiber — the water-soluble and the water insoluble — are coveted because they can prevent disease and help detoxify the body. The role of fiber is not to provide the body with nutrition, as fiber itself has no minerals or vitamins. Instead, the role of fiber is to act as a natural broom that sweeps the intestines clean of toxins and excess waste through regular bowel release.
The constant cleaning of the digestive tract can reduce the time that poisonous substances and malicious bacteria remain in the body, thereby guarding against illnesses like cancer, particularly colon cancer. In addition to cleansing the body and preventing malignancies, high-fiber diets can reduce cholesterol in the body. This reduction occurs because fiber removes digestive juices known as bile, which is made from cholesterol. The constant removal forces the body to produce more bile by drawing more cholesterol out of the bloodstream.
Fiber can also lower blood sugar, which is helpful for people who have diabetes. It does this by lingering in the digestive tract with simpler sugars, delaying the sugar’s breakdown and entry into the bloodstream. Doctors often recommend that dieters eat simple carbohydrates with high-fiber foods to maintain balanced blood glucose.
In pursuit of these benefits, many people add large amounts of complex carbohydrates to their daily diet and occasionally end up adding too much fiber. Nutritionists say it’s highly unlikely that a person eating whole foods can consume an excessive amount of fiber, as most fruit and vegetable servings only have between one gram and 4 grams of fiber each. Servings of grain can have as many as 11 grams of fiber; however, because they induce fullness quickly, nutritionists believe most people are not likely to consume too much fiber from grain. If the body, however, is not accustomed to lots of fruits, legumes and grains a day, it may temporarily react with gas and cramping until the digestive system is used to regular high-fiber consumption.
Taking fiber supplements is where the danger of excess lies, according to doctors. Capsules of fiber and dried fiber sold to be added to liquids like water and fruit juice by the spoonful can easily be consumed in excess. When too much fiber is consumed through supplementation, the likelihood of becoming malnourished is higher because whereas whole foods contain replenishing nutrients in addition to fiber, fiber supplements generally have only fiber and a few preservatives. Doctors often recommend that those who take fiber in supplement form regularly take vitamins and limit consumption to the recommended daily allowance listed on the product.