Simple Food Terms – Fiber Explained
Nutrition Apr 19, 2017
Simple Food Terms – Fiber Explained

You’re probably familiar with the term “high fiber diet” or have been encouraged by your health care provider to engage in one. But do you know why it’s important to eat lots of fiber? Or what foods have dietary fiber and what it can do for you? In this installment of Simple Food Terms Explained Series, we discuss dietary fiber and its benefits.

What is Dietary Fiber?

Dietary fiber is the parts of plant foods that cannot be digested or absorbed. Unlike carbohydrates, proteins, and fats, fiber passes through the body undigested.

There are 2 types of dietary fiber:

Soluble Fiber: This type of fiber dissolves in water and forms a gel. This gel then passes through the body without being absorbed. It binds to cholesterol and carries it out of the body. Therefore, it helps to lower cholesterol levels. Good food sources of soluble fiber include oats, dried beans (such as pintos, lentils, and black beans), citrus fruit (such as oranges), and barley.

Insoluble Fiber: Insoluble fiber does not dissolve in water. It helps to move food through your digestive tract and it adds bulk to stools. This quality makes it beneficial in relieving constipation. Good food sources of insoluble fiber include whole wheat flour, wheat bran, nuts, dried beans (such as pinto and black beans), and vegetables (such as cauliflower, green beans, and potatoes).

Why You Should Eat More Dietary Fiber

Fiber slows things down by being a physical block so the absorption of sugar, fats, etc… are slowed down as well. Eating dietary fiber can help lower your cholesterol and relieve or prevent constipation.

However, these are not the only benefits. Increasing dietary fiber intake also helps:

Lower blood sugar levels: Foods high in fiber take longer to digest and absorb. With fiber being a physical block, it also slows sugar consumption, which prevents spikes in blood sugar. This means the sugar from those foods takes longer to digest and absorb, resulting in a slower and lower rise and drop in blood sugar levels after eating.

Prevent hemorrhoids and diverticulosis: A high fiber diet keeps food and waste moving efficiently and effectively through the digestive tract. This helps prevent development of pouches in the large intestine (diverticuli). This also makes bowel movements easier to pass which reduces the risk of developing hemorrhoids.

Promote weight loss: High fiber foods are more filling, which can decrease the total amount of food you eat at meals and snacks. They also tend to be lower in calories.

How to Get More Fiber in Your Diet

As a general guide, women 50 years and younger need 25 gm dietary fiber daily, and men 50 years and younger need 38 gm daily. After age 50, women require 21 grams daily, and men require 30 grams daily.

Dietary fiber is found in plant foods. In general, foods that are highly processed contain less fiber as most of the fiber is lost during processing. For example, fresh fruit has more fiber than canned fruit. Try replacing processed foods with fresh fruits and vegetables as an easy way to increase your daily fiber intake.

High fiber foods include:

  • whole grain breads and cereals
  • brown rice
  • fresh fruits and vegetables such as apples and carrots
  • oats
  • beans, peas, and other legumes
  • nuts and seeds

How to Get Started

If you normally eat a very low fiber diet, gradually increase your dietary fiber intake. A sudden, large increase in dietary fiber intake can cause gastrointestinal discomfort, bloating, and gas. Also, make sure to drink plenty of water when you increase fiber intake. This helps keep stools soft and easy to pass.

Read labels closely. A loaf of bread labeled “wheat” or even “whole wheat” is not necessarily high in fiber. Make sure to look at the serving size and the grams of dietary fiber. A true whole grain bread has at least 2 grams of fiber per slice. Some brands list the serving size as 2 slices and others as 1 slice. Make sure you look at the serving size to make a good comparison between different types of bread (and other foods).

Stay tuned for our next installment where will decipher another simple, but often confusing, food term.