The Importance of Fiber and How to Get It

Fiber may not be trendy, but it’s a nutritional powerhouse essential to your gut and heart health, weight management, and cancer prevention. Despite its importance, most people don’t get enough—leading to digestive issues, inflammation, and increased disease risk.

In this article, we’ll break down the science-backed benefits of dietary fiber, how it improves gut and colon health, its role in preventing chronic illness, and how you can boost your intake naturally through food and supplements.

Quick Look: What You’ll Learn About Fiber

For those short on time, here’s a fast overview of what this post covers:

1. What is fiber? A plant-based nutrient that supports digestion, heart health, and colon health.
2. How much do you need? 25–38 grams daily.
3. Top high-fiber foods: Chia seeds, lentils, raspberries, oats, and broccoli.
4. Surprising sources: Avocados, popcorn, potatoes (with skin), unripe bananas.
5. Fiber supplements: Use psyllium, inulin, or PHGG for digestive support.
6. Health benefits: Aids in weight loss, lowers cholesterol, balances blood sugar, reduces colon cancer risk.

What Is Fiber?

Fiber is the indigestible portion of plant foods. Unlike fats and proteins, fiber resists digestion in the stomach and small intestine, reaching the colon mostly intact, where it:

• Feeds good gut bacteria
• Regulates bowel movements
• Supports metabolism
• Lowers cholesterol and blood sugar

Two Main Types:

• Soluble fiber: dissolves in water and forms a gel-like substance; slows digestion and helps lower cholesterol (e.g., oats, chia seeds).
• Insoluble fiber: adds bulk to stool and helps food pass quickly through the digestive system (e.g., vegetables, whole grains).

Fiber and Gut Health: A Symbiotic Relationship

Fiber is fuel for your gut microbiome—the trillions of bacteria living in your intestines.

Research-backed facts:

• Prebiotic fibers (such as inulin) feed beneficial bacteria that produce short-chain fatty acids (SCFAs).
• SCFAs, especially butyrate, reduce gut inflammation and protect against conditions such as IBS, leaky gut, and ulcerative colitis.
  

Fiber’s Role in Colon Cancer Prevention

Colon cancer is largely influenced by diet. A fiber-rich diet helps:

• Reduce transit time: fiber moves waste faster through your colon, minimizing exposure to potential carcinogens.
• Dilute harmful compounds in stool.
• Increase butyrate production—an SCFA with anti-inflammatory and anti-cancer properties.

Evidence:

• A meta-analysis published in BMJ found a 10g/day increase in fiber was associated with a 10% reduced risk of colorectal cancer.

How Much Fiber Do You Need?

Daily fiber needs vary by age and sex. For adults ages 19–50, women are advised to consume about 25 grams of fiber per day, while men should aim for 38 grams per day.

After age 50, fiber requirements decrease slightly, with recommendations of 21 grams per day for women and 30 grams per day for men.

Despite these clear guidelines, most people fall far short—averaging only 15–17 grams of fiber daily, which is well below the minimum needed to support optimal gut and metabolic health.

Top 5 High-Fiber Foods to Add to Your Diet

1. Chia Seeds – 10g per 2 tablespoons

• These tiny seeds pack a serious fiber punch—about 40% of their weight is fiber.
• Rich in soluble fiber, they form a gel in your stomach, helping with satiety and blood sugar control.
• Also a great plant-based source of omega-3 fatty acids.

2. Lentils – 15.6g per cup (cooked)

• Lentils are fiber superstars, offering both soluble and insoluble fiber.
• Rich in plant protein, iron, magnesium, and B vitamins.
• Promote regularity and are especially helpful for lowering cholesterol and stabilizing blood sugar.

3. Raspberries – 8g per cup

• One of the highest-fiber fruits, raspberries are low in sugar but high in antioxidants.
• Contain ellagic acid, a compound studied for its anti-cancer properties.
• Their fiber helps with digestion, weight control, and gut health.

4. Oats – 4g per cup (cooked)

• Oats are rich in beta-glucan, a soluble fiber proven to lower LDL (“bad”) cholesterol.
• Help maintain healthy blood pressure and reduce appetite.
• Offer slow-digesting carbs, ideal for blood sugar control.

5. Broccoli – 5g per cup (cooked)

• Loaded with insoluble fiber and nutrients like vitamin C, K, and sulforaphane, a compound linked to reduced cancer risk.
• Supports healthy digestion and feeds beneficial gut bacteria.

Surprising High-Fiber Foods You Might Not Know About

Some fiber-rich foods fly under the radar but are easy to add to your diet.

Avocados 

Provide approximately 10 grams of fiber per whole avocado, and unlike most fruits, they are rich in both healthy fats and fiber, making them especially supportive of gut, satiety, and cardiovascular health.

Baked potato with the skin

Contains about 4 grams of fiber, with most of the fiber concentrated in the skin, and it is also an excellent source of potassium, which plays a key role in blood pressure regulation.

Air-popped popcorn

Delivers roughly 3.5 grams of fiber per 3 cups, making it a whole-grain snack naturally high in fiber, as long as heavily buttered or sugar-coated versions are avoided.

Unripe (slightly green) bananas

Provide about 3 grams of fiber per medium banana and are particularly high in resistant starch, a prebiotic fiber that helps nourish beneficial gut bacteria.

Fiber Supplements: When to Use Them & Which to Choose

While whole foods are the best fiber sources, supplements can help fill gaps—especially if you have digestive issues, dietary restrictions, or a low-carb diet.

Recommended Fiber Supplements:

• Psyllium Husk (e.g., Metamucil): High in soluble fiber; helps with constipation, cholesterol, and IBS.
• Inulin: A prebiotic fiber that nourishes the microbiome and supports calcium absorption.
• PHGG (Partially Hydrolyzed Guar Gum): Gentle on the digestive system and effective for IBS-D (diarrhea-dominant).

Fiber Supplements to Avoid or Use with Caution:

• Wheat Dextrin (e.g., Benefiber): Low prebiotic effect and less effective for microbiome health.
• Fiber-enriched processed foods: Often contain synthetic fibers and added sugars, which can cause bloating.

Tips:

• Always increase fiber gradually to avoid gas and bloating.
• Drink plenty of water to keep things moving smoothly.

Quick Tips to Boost Daily Fiber Naturally

Boosting daily fiber intake can be done naturally with a few simple, sustainable habits. Adding beans or lentils to meals several times per week is one of the easiest ways to increase fiber while also providing plant-based protein.

Choosing fiber-rich snacks such as nuts, seeds, and fruits like apples, berries, and pears helps close the daily fiber gap between meals. Opting for whole grains—such as brown rice, quinoa, and whole wheat—over refined grains further increases fiber intake, while blending vegetables into smoothies or soups is a practical strategy for those who struggle to eat enough produce.

Small additions also matter; sprinkling flax or chia seeds onto salads, yogurt, or cereal can significantly boost fiber without changing meal structure.

Bonus Benefits of Fiber

Beyond digestive health, fiber plays a critical role in preventing chronic disease. Higher fiber intake supports weight management by increasing feelings of fullness, which naturally reduces overall calorie intake.

Soluble fiber helps lower cholesterol by binding to it in the digestive tract and promoting its removal from the body.

Fiber also stabilizes blood sugar by slowing digestion and reducing insulin spikes after meals.

Importantly, long-term studies have shown that diets high in fiber are associated with a substantially lower risk of cardiovascular disease, with large population data linking high-fiber intake to approximately a 30% reduction in heart disease risk.

To learn more about the importance of diet and heart health, be sure to read: The Best Diet for Heart Health Isn’t Perfect — It’s Sustainable

Conclusion: Feed Your Body and Your Gut

Fiber isn’t just about staying regular—it’s a foundation for long-term wellness, disease prevention, and vibrant energy. Whether through chia seeds, broccoli, lentils, or avocado, reaching your fiber goals is easier than you think. And if food alone isn’t enough, smart supplementation can help bridge the gap.

Frequently Asked Questions

Why is fiber important for gut health and overall wellness?

Dietary fiber supports gut health by feeding beneficial gut bacteria, improving digestion, and promoting regular bowel movements. It also helps regulate blood sugar, lower cholesterol, reduce inflammation, and lower the risk of chronic diseases such as heart disease and colorectal cancer.

How much fiber should you eat per day for optimal health?

Most adults should aim for 25–38 grams of fiber per day, depending on age and sex. However, the majority of people consume significantly less, which can negatively impact digestive health, metabolic function, and long-term disease risk.

What are the best food sources of dietary fiber?

High-fiber foods include legumes such as lentils and beans, seeds like chia and flax, fruits such as berries and avocados, vegetables including broccoli and leafy greens, and whole grains like oats and quinoa. A variety of plant foods helps support both digestion and microbiome diversity.

Are fiber supplements as effective as fiber from food?

Whole foods are the best source of dietary fiber because they provide additional nutrients and antioxidants. Fiber supplements can be helpful for filling gaps when dietary intake is low, but they work best as a complement—not a replacement—for fiber-rich foods.

About the Author:

Dr. Ray Rivas is a medical doctor, former trauma surgeon, and the founder of Innerbloom Ketamine Therapy, a clinic dedicated to advancing mental health care through innovative treatments. With a deep passion for holistic wellness, he also leads Newy, a nootropic supplement company designed to support brain health. Drawing on decades of clinical expertise, a career focused on mental health, and personal experiences with growth and healing, Dr. Rivas is devoted to empowering individuals with the tools they need to achieve lasting mental and physical health.

Disclaimer:

The content provided on this blog and website is for educational and informational purposes only and should not be considered medical advice. Newy supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before starting any new supplement, especially if you are pregnant, nursing, have a medical condition, or are taking other medications.

References:

Aune, Dagfinn, et al. “Dietary Fibre, Whole Grains, and Risk of Colorectal Cancer: Systematic Review and Dose‑Response Meta‑Analysis of Prospective Studies.” BMJ, vol. 343, no. d6617, 2011, doi:10.1136/bmj.d6617. 

Kaczmarczyk, Melissa M., Michael J. Miller, and Gregory G. Freund. “The Health Benefits of Dietary Fiber: Beyond the Usual Suspects of Type 2 Diabetes Mellitus, Cardiovascular Disease and Colon Cancer.” Metabolism: Clinical and Experimental, vol. 61, no. 8, Aug. 2012, pp. 1058‑1066, doi:10.1016/j.metabol.2012.01.017. 

Makki, K., et al. “The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease.” Cell Host & Microbe, vol. 23, no. 6, June 2018, pp. 705‑715, doi:10.1016/j.chom.2018.05.012.

Veronese, Nicola, et al. “The Impact of Dietary Fiber Consumption on Human Health: An Umbrella Review of Evidence from 17,155,277 Individuals.” Clinical Nutrition, vol. 51, 2025, pp. 325–333, doi:10.1016/j.clnu.2025.06.021.