The Benefits of a High-Fiber Diet

There is no doubt that recent literature has shown the positive effects of a high intake of dietary fiber on your body and health. In fact, high-fiber diets have been researched and studied extensively for their benefits on various conditions and health outcomes. 

But what exactly is a high-fiber diet and what types of conditions can it help with?

That is what I plan to discuss in today’s article! As a registered dietitian, I will be walking through what a high-fiber diet is and what the benefits are for various chronic conditions. 

These conditions include diabetes and insulin resistance, hormonal imbalances, high cholesterol, and heart disease. Make sure to save this post for later and share it with anyone who you feel may benefit! 

Interested in working with a specialized dietitian nutritionist? If you haven’t already, make sure to check out my services page to find out about my current offers!

What is a High-Fiber Diet?

Fiber is found in only plant-derived products and goes primarily undigested until it reaches your colon. Dietary fiber is traditionally defined as "any nondigestible carbohydrate and lignin not degraded in the upper gut". High-fiber diets focus on getting an increased amount of fiber throughout the day from a variety of high-fiber food sources. The goal is to eat the number of grams equal to or above the recommended dietary allowance for fiber. 

Currently, the minimum daily fiber recommendations are:

• Woman: 25 g/day

• Men: 38 g/day

• Or 14 grams per 1,000 kcal eaten

When tracking your grams of fiber, make sure to look at the food label and check under “carbohydrates”. That will tell you the number of grams of fiber per serving. Keeping a food journal may be helpful, especially at first! Next, I will talk more about the different types of fiber and some high-fiber food sources. 

Types of Fiber and Food Sources

There are two types of fiber: soluble and insoluble fiber. Both types of fiber have beneficial outcomes for your health and should be included in a high-fiber diet.

The two types of fiber are:

• Soluble: soluble fiber is able to dissolve in water. It turns to gel during digestion

  • Sources: beans, legumes, oats, seeds

  Insoluble: insoluble fiber cannot dissolve in water or GI fluids and remains mostly unchanged

  • Sources: wheat bran, vegetables, brown rice

Some other foods high in fiber are:

• Fruits (raspberries, pears, apples), nuts, barley, split peas, cruciferous vegetables, and more

Incorporating dietary fiber into your day can have a variety of benefits for your body. This includes having a positive impact on the prevention and management of various conditions. 

These conditions include:

• Cardiovascular disease

• Diabetes/Insulin resistance

• High cholesterol

• Stroke

• Colon cancer

• Hormone imbalances

• Breast cancer

• and more!

Keep reading to briefly learn more about the benefits of fiber in a few specific conditions! 

Benefits for Diabetes and Insulin Resistance

Diabetes, prediabetes, and insulin resistance affect a significant number of Americans every year. Insulin resistance is when your body stops responding properly to the hormone insulin and your body has to produce more to make up for it. Insulin resistance can eventually lead to diabetes, prediabetes, and even other conditions such as Polycystic Ovarian Syndrome (PCOS). High-fiber diets have been shown to be beneficial for insulin resistance and diabetes through a number of mechanisms. 

First off, studies show that high-fiber diets reduce your risk of developing type 2 diabetes by 20-30%. 

If you already have diabetes, they can help with greater improvement in glycemic control, decreased hyperinsulinemia, and lowered plasma lipid concentrations.

This is because as fiber goes through your GI tract, it slows the absorption of glucose. Since your body can not fully digest fiber, it is not broken down in your body the same way regular carbohydrates are. Your blood sugar does not spike and stays more within the target range. 

Additionally, it also stimulates the production of mucous which encourages a healthy gut microbiome. A healthy gut has been shown to be beneficial for insulin resistance and diabetes.

Benefits for Hormone Imbalances

The current literature shows that high consumption of dietary fiber is significantly associated with lower concentrations of reproductive hormones. Therefore a high-fiber diet may be beneficial for women dealing with hormone imbalances and other related conditions.  The main hormone that fiber has an effect on lowering is estrogen. The mechanism appears to be through decreasing β-glucuronidase (an enzyme) activity in feces which leads to decreased reabsorption of estrogen in the colon. It also binds to estrogen in the intestine, increasing how much is excreted through stool.  Since fiber affects estrogen, it can also subsequently affect other reproductive hormones. This is due to strict feedback mechanisms, which influence hormonal fluctuations during a menstrual cycle. It can affect both your luteinizing hormone and follicle-stimulating hormone, even when independent of estrogen. Since fiber can lower estrogen levels, a high-fiber diet has been used to treat estrogen dominance and conditions related to it. A few of these conditions include breast cancer, fibroids, PCOS, endometriosis, and more. 

Benefits for Cholesterol and Heart Disease

As we mentioned earlier when talking about insulin resistance, fiber has the ability to lower plasma lipid concentrations within your body. There is plenty of recent studies that confirm high-fiber diets can have a positive impact on reducing total cholesterol, LDL cholesterol, and triglycerides.  So, how does this work? Well, fiber grabs onto cholesterol and fat in the GI tract (small intestine) and excretes it instead of absorbing it into your bloodstream. Since fiber reduces blood lipid levels, it can also be beneficial for preventing and managing heart disease. It even has other heart-healthy benefits such as reducing blood pressure and inflammation in your body.  Individuals who consume a high amount of fiber can significantly reduce their risk of incidence and mortality from cardiovascular disease. I encourage anyone with high cholesterol to consider a high-fiber diet!

High-Fiber Diets: The Takeaway

All in all, increasing the fiber in your diet can have a wide array of benefits for your body. For best results, focus on food sources that include both soluble and insoluble fiber. Your nutrition can play a huge role in how your body functions and feels. High-fiber diets are a relatively low-cost and low-risk way to prevent and manage various chronic conditions. If you are looking for extra guidance and assistance, working with a dietitian may be right for you! A registered dietitian nutritionist like myself can help you plan and structure your meals to make sure they include high-fiber food sources.

Head over to my services page to learn more about my services and offers. There is no better time to invest in your health!