How much fiber an individual should consume is a common question for dieticians and physicians. The answer is that it is based upon and individual’s diet and daily calorie intake. The United States Institute of Medicine recommends 20-35 grams of dietary fiber per day. Usually, this is broken down by age and gender. Men and teens usually require an average of 30 grams/day while women and young children generally require about 20 grams per day.
A good rule of thumb is to consume 14 grams of fiber for every 1,000 calories in your diet. Since estimates indicate that the average American consumes only 10-15 grams of fiber per day, it is a safe bet that you are not getting enough and should increase your intake.
So, where can you get the fiber you need and why do you really want it in the first place? To answer the first question, dietary fiber can be found in all manner of fruits and vegetables, such as peas, citrus fruits, and strawberries. Whole grains are also an excellent source. Beans of any kind are probably one of the best sources of fiber available and can be added to many dishes and meals.
So, now that you know where to find the fiber, why do you really want it in the first place? To answer that question, let’s look at the types of fiber. Fiber is broken down into two categories: soluble and insoluble. Soluble fiber is able to dissolve in water. Once in the GI tract, it forms a kind of Jell-O-like mixture that has numerous health benefits.
Soluble fiber can bind bile salts, which contain high amounts of cholesterol. By binding these salts and preventing their absorption in the GI tract, soluble fiber can reduce cholesterol levels. In fact, adding fiber to a diet that is low in fat and cholesterol leads to substantially lower LDL (Bad) cholesterol levels than a low fat, low cholesterol diet that does not contain fiber.
In addition to its cholesterol lowering properties, soluble fiber also slows the absorption of glucose in the GI tract, which can help reduce sugar loads on the body and decrease the risk of diabetes. Both diabetes and cholesterol are risk factors for heart disease, so the consumption of fiber can help to reduce the risk of heart disease substantially. In addition, fiber also reduces the risk of diverticular disease and helps to fight obesity.
The other type of fiber, insoluble fiber, cannot be dissolved in water. Its primary health benefits are the result of stool bulking. Because it is insoluble, this type of fiber increases the rate of transit in the GI tract, which reduces constipation and leads to more regular bowel movements.
Now, it is possible to consume too much fiber. If you should increase the amount of fiber in your diet and then notice that you are experiencing excessive gassiness, bloating, abdominal pain, or unusually large stools, then it is likely that you are added too much fiber to your diet or that you have added the right amount to fast.
Sometimes, when the GI tract is not used to processing a large amount of fiber (such as in the typical American diet) it overreacts to an increase. The way to combat this problem is to lowly increase fiber intake over 4-8 weeks.
Finally, fiber is often touted as a way of treating irritable bowel syndrome (IBS). This is only partially true and those suffering from IBS should be cautious when adding fiber to their diet. Fiber is generally most beneficial in IBS patients who suffer from constipation. In these individuals it can add bulk and decrease stool transit times leading to softer bowel movements.
In IBS patients who suffer from diarrhea, fiber can often worsen the symptoms of the disease. If you suffer from IBS, then the best strategy for adding fiber to your diet is to go slowly. If you do not notice any benefit after 4-6 weeks or your symptoms worsen, it is probably prudent to reduce your fiber intake back to baseline.
In the end, most Americans could use a bit more fiber in their diets. The key to adding it is to choose foods you enjoy that contain it and slowly increase their content in your diet. The benefits of getting the right amount of fiber are a healthier, longer life.