The Facts on Fiber

Kristin Kirkpatrick January 03, 2024

Are you getting enough fiber in your diet? If you are like most Americans, you’re probably not. Further, consuming less than recommended amounts can impact your risk for chronic disease and longevity. Here's why fiber is so important and why getting more of it is easier than you think.

Fiber 101

Let's first start with the basics of fiber. Fiber is a type of carbohydrate that comes from plants. The body cannot break down fiber, and that's one of the reasons why it has so many benefits. There are two types of fiber, soluble and insoluble. The classification of each is determined by how soluble they are in watery environments like the intestinal tract.

Soluble fiber dissolves in water (think about oatmeal softening and absorbing water as it is cooked) and, once in the body, turns into a gel-type substance. Soluble fiber sources have been shown to help in the management of cholesterol and blood sugar. Sources of soluble fiber include oats, beans, and legumes, as well as fruits like apples and avocados and vegetables like broccoli and carrots.

Insoluble fiber does not dissolve in water (think the skin of an apple that stays the same when dunked in water). Insoluble fiber passes largely undigested through the digestive tract and helps to move bulk through the system which may assist in keeping you "regular." Sources of soluble fiber include corn, peas, whole grains, nuts, and the skin of fruits and vegetables such as green beans and kale.

Both forms of fiber are essential. The recommended fiber intake for healthy adults is between 25g (for females) and 38g (for males) a day. It is also recommended to build up to these levels to allow the gastrointestinal (GI) tract to adjust.

The health benefits of adequate fiber intake

Better gut health

In the past decade, researchers have found that the gut is a powerful component of overall health, including both physical and mental health. One of the major players in gut health is the types of bacteria that reside within it, which are known as our GI microbiota. Having a healthy microbiota, in turn, can impact metabolic health, longevity and even mood. Fiber plays a significant role in gut health due to its impact on the microbiota living in the large intestine. A diet that is high in fiber feeds the gut microbiota, who then produce more short-chain fatty acids that help to reduce the risk of chronic disease. Recent studies have even attributed good gut to an overall skin health and a reduced risk of depression.

Better management of weight and blood sugar

Studies show that adequate fiber intake can help in the management of blood sugar, as well as weight. Since fiber is not digestible, it slows the digestion and absorption of other carbohydrates, and research shows it may help in creating satiety and reducing appetite. Due to these benefits, the CDC has identified fiber as having a positive impact on managing the risk of diabetes.

Reduction of risk of cardiovascular disease

Fiber intake can help manage dyslipidemia, which can assist in reducing the overall risk for heart attack and stroke. A systematic review and meta-analysis in the British Medical Journal found that the more fiber that is consumed, the lower the overall risk of heart disease.

How to get more fiber while still living a low carbohydrate lifestyle

If you are adhering to a low-carb lifestyle, getting your daily dose of fiber is easy. That's because fiber comes in many low carb foods such as nuts, seeds, berries and cruciferous vegetables. If your goal is a moderate carbohydrate approach, then adding small portions of steel cut oats or other intact grains can further boost your levels.

Get more fiber and your body and health will love you for it. Add in a few servings of cruciferous vegetables, have nuts over potato chips as a snack, add seeds to your salads!