What is fiber and why is it important?

Fiber is an important part of the diet that affects our health in many ways. Fiber is a carbohydrate found in plants that the body cannot digest. 


Most carbohydrates are broken down into sugar molecules that the body uses for energy, but fiber cannot be broken down into sugar. Instead, fiber passes through the body undigested. 


Fiber comes in two forms, both of which are beneficial to health:

  • Insoluble fiber - This type of fiber does not dissolve in water. It can help food move through your digestive system, promote regularity, and prevent constipation. Foods with insoluble fibers include wheat, whole wheat bread, whole grain couscous, brown rice, legumes, carrots, cucumbers, and tomatoes. 
  • Soluble fiber - This type of fiber dissolves in water. It can help lower glucose levels as well as lower blood cholesterol. Foods with soluble fiber include oatmeal, nuts, beans, lentils, apples, and blueberries.

It’s important to include both types of fiber in your diet, as they each serve a different purpose in the body. 


Health Benefits of Fiber 


Research shows that consuming adequate fiber can reduce the risk of developing health complications including constipation, heart disease, diabetes, and diverticular disease. 


Heart Disease


A diet high in fiber has been shown to significantly decrease the risk of heart disease in many studies that followed participants for a number of years. 


One study showed that a high intake of dietary fiber was correlated with a 40% decrease in risk for coronary heart disease in males. Another study found similar results for a high-fiber diet in females


High-fiber diets have also been shown to have a cholesterol-lowering effect. Soluble fiber found in beans, oats, flaxseed, and oat bran may help lower total blood cholesterol levels by lowering LDL, or "bad," cholesterol levels. 


Studies also have shown that high-fiber foods may have other heart-health benefits, such as reducing blood pressure and inflammation. 


Diabetes 


Diets low in fiber and high in simple carbohydrates increase the risk of developing type 2 diabetes. 


A healthy diet that includes insoluble fiber may reduce the risk of developing type 2 diabetes. 


For people who have diabetes, soluble fiber can slow the absorption of sugar from food and improve blood sugar levels. 


Gut Health


A high-fiber diet has many benefits for digestion and gut health. Including adequate amounts of both soluble and insoluble fiber in the diet normalizes bowel movements and helps maintain gut health. 


Constipation is the most common gastrointestinal complaint in the United States. Increasing fiber consumption can help relieve this problem. 


Dietary fiber increases the weight and size of the stool and softens it. A bulky stool is easier to pass, decreasing the chance of constipation. If stools are loose and watery, fiber may help to solidify the stool because it absorbs water and adds bulk to the stool.


Insoluble fiber, the kind found in wheat bran and oat bran, is considered more effective for bowel health than fiber from fruits and vegetables. 


A high-fiber diet may also lower the risk of developing hemorrhoids and diverticular disease. 


Studies have found that a high-fiber diet may lower the risk of colorectal cancer. Some fiber is fermented in the colon. Researchers are looking at how this may play a role in preventing diseases of the colon.


Weight Management

High-fiber foods are usually more filling than low-fiber foods, so you're likely to eat less and feel full longer. 


Foods with a high fiber content tend to take longer to eat and are often less "energy-dense," which means they have fewer calories for the same volume of food. 


This can help with weight loss and in maintaining a healthy weight. 


What Happens if We Don’t Eat Enough Fiber?


Not getting enough fiber can have serious effects on one’s health. We’ve discussed the benefits of including fiber in your diet, so just imagine what can happen if you are not getting enough. 


A diet high in protein and low in carbohydrates (including fiber) can cause higher levels of blood cholesterol, and also leave you feeling tired and weak. Inadequate fiber intake may also cause unhealthy fluctuations in blood sugar and lead to constipation. 


It is important to include a variety of fiber-containing foods in your diet to promote overall health. 


How Much Fiber Do You Need?


The recommended amount of dietary fiber per day is about 25-40 grams for adults. 


Women under 50 should aim for about 25 grams of fiber per day, while men under 50 should get about 38 grams. Women over 50 need about 21 grams per day, and men over 50 need about 30 grams. 


Too much fiber in the diet can cause bloating, gas, and discomfort. The severity of this discomfort occurs relative to the amount of fiber that the body is used to. Some sources suggest that consuming more than 70 grams of fiber per day can have negative effects. 


If you aren’t currently consuming much fiber in your diet, gradually increase your fiber intake to 25-35 grams over the course of a couple of weeks. 


Be sure to drink at least 64 oz of water per day as you increase your fiber intake. You may need even more fluid as you eat higher amounts of fiber. Fluid helps your body process fiber without discomfort.


Good Sources of Fiber 


It’s important to include both soluble and insoluble fiber in your diet, as they each serve a different purpose. Some excellent sources of both soluble and insoluble fiber include:

  • Bran cereal
  • Beans and legumes
  • Soybeans
  • Raspberries
  • Artichokes
  • Pears
  • Avocados
  • Beets
  • Broccoli
  • Quinoa
  • Baked potatoes with skin
  • Almonds
  • Oats

Try these ideas to increase your fiber intake 

  • Choose breakfast cereals that have whole grain as their first ingredient
  • Check the nutrition labels and try to choose products with at least 4 g dietary fiber per serving
  • Eat whole fruits instead of drinking fruit juices
  • Use whole grain products and brown rice in place of white rice, bread, and pasta
  • Snack on raw vegetables instead of chips, crackers, or cookies
  • Enjoy meatless meals more often by substituting beans and legumes for meat two to three times per week

Fiber is an important nutrient that is not to be missed. It plays an important role in gut health, cardiovascular health, and metabolic health. Eat a variety of plant-based foods to ensure you are getting enough fiber in your diet.