Why Some People Thrive on High-Fiber Diets, and Others Don’t

Fiber gets a lot of praise, and for good reason. It’s often hailed as the key to better digestion, heart health, and stable blood sugar. For many, increasing fiber is a game-changer—it leaves them feeling full, energized, and balanced. But for others, a high-fiber diet can feel like an uphill battle, causing bloating, discomfort, or worse.

So why does something that’s universally celebrated work so well for some and not for others? The answer lies in the beautifully complex and deeply individual nature of our bodies. Let’s unpack the factors at play and help you navigate fiber in a way that works for you.

The Basics of Fiber

Fiber is a type of carbohydrate found in plant-based foods. Unlike other carbs, your body doesn’t fully digest fiber.

Instead, it passes through your digestive system, where it does one of two things: Insoluble fiber acts like a broom, adding bulk to your stool and helping food move through your digestive system. Think of foods like whole grains, nuts, and the skins of fruits and vegetables.

Soluble fiber dissolves in water, forming a gel-like substance that can help regulate blood sugar and lower cholesterol. You’ll find it in foods like oats, beans, and apples.

Both types of fiber are important, but how your body responds to them depends on factors unique to you.

Why High-Fiber Diets Work for Some

For many people, fiber is the missing piece in their diet. It helps with regularity, keeps them feeling full between meals, and supports the growth of beneficial gut bacteria.

When fiber moves through your digestive system, it acts as food for your microbiome—the trillions of bacteria living in your gut. These bacteria ferment fiber, producing short-chain fatty acids that nourish your gut lining and reduce inflammation. This process supports everything from digestion to immune health.

For those with a healthy, diverse microbiome, adding more fiber can feel like fueling a well-tuned engine. It promotes smooth digestion, stabilizes energy, and enhances overall well-being.

If you’ve ever tried to add more fiber to your diet only to feel worse, you’re not alone. While fiber offers undeniable benefits, it’s not a one-size-fits-all solution.

Here’s why:

1. An Unbalanced Gut Microbiome

If your gut bacteria are out of balance—due to stress, illness, or a history of antibiotics—your microbiome might struggle to process fiber. Without enough of the “good” bacteria that thrive on fiber, adding more can lead to excessive fermentation, gas, and bloating.

2. Digestive Conditions

Conditions like irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO) can make it harder to tolerate fiber. For example, certain high-fiber foods, like beans or broccoli, might trigger symptoms because they ferment too quickly or produce excess gas in the small intestine.

3. Rapid Changes

Adding too much fiber too quickly can overwhelm your digestive system, especially if you’re not used to it. It’s like suddenly putting your body on a high-speed treadmill when you’ve been walking at a leisurely pace.

4. Not Enough Water

Fiber needs water to do its job. Without adequate hydration, fiber can have the opposite effect, leading to constipation or discomfort.

How to Find Your Fiber Sweet Spot

If you’re not thriving on a high-fiber diet, it doesn’t mean fiber isn’t for you—it just means you might need to approach it differently.

Start Slowly

If your diet has been low in fiber, introduce it gradually. Instead of jumping straight to three servings of beans, start with a handful of leafy greens or a small serving of oats. Give your body time to adjust.

Pay Attention to Types of Fiber

Not all fiber affects your body in the same way. If insoluble fiber feels harsh, focus on soluble fiber sources like cooked carrots, zucchini, or peeled apples. These tend to be gentler on the digestive system.

Support Your Microbiome

A diverse microbiome is key to processing fiber effectively. Include fermented foods like yogurt, kimchi, or sauerkraut to introduce beneficial bacteria. Prebiotic foods like garlic, onions, and bananas can also help feed your existing good bacteria.

Stay Hydrated

Water is essential for fiber to work properly. Make sure you’re drinking enough throughout the day, especially as you increase fiber intake.

Cook Your Veggies

Cooking can break down the structure of fiber, making it easier for your body to process. If raw vegetables feel too rough, try steaming, roasting, or sautéing them instead.

Listening to Your Body

One of the most important things you can do when it comes to fiber—or any aspect of your diet—is listen to your body. Pay attention to how you feel after meals. Are you energized and comfortable or bloated and sluggish? These signals are your body’s way of guiding you toward what it needs.

If high-fiber foods don’t feel good, don’t force them. You can always adjust, experiment, and find the right balance for your unique system.

Fiber is an essential part of a healthy diet, but how it works for you depends on your body’s individual needs and your gut’s unique ecosystem. If you’ve struggled with high-fiber diets in the past, it doesn’t mean you’re doing something wrong. It simply means your body might need a different approach.

Content Copyright © 2025, MBK Cultivate Skin & Nutrition Wellness   

PERMISSION TO REPRINT: You may use any items from this article in your print, blog, magazine, or electronic newsletter. However, you must include the following paragraph, including a link to www.mebykatie.com.   

"Information courtesy of www.mebykatie.com; Katie Marshall is a certified Medical Esthetician, Acne Specialist, Functional Nutrition Counsellor, Holistic Chef, and Integrative Nutrition Health Coach. Specializing in skin health, gut health, hormone health, and the whole body. The basic premise is that functional nutrition gets to the root of the problem and resolves the actual problem. This differs from conventional medicine, which often prescribes multiple medications to manage symptoms, with little regard for addressing the root cause of the symptoms. Functional nutrition is more personalized, customized, and holistic. My job is to work with your medical team and advocate for you if necessary."   

Health/Medical Disclaimer:   

The content of MBK Cultivate Skin & Nutrition Wellness, either through these social media pages, websites, or any other materials distributed by MBK Cultivate Skin & Nutrition Wellness, is intended to provide helpful and informative material. Please remember that my personal and professional opinions on these social media pages and websites are solely my own. This site offers information on skin, diet, fitness, health, and nutrition, and is designed in good faith for educational purposes only. Care has been taken to confirm the accuracy of the information and describe generally accepted practices. However, the authors, editors, and publishers are not responsible for errors, omissions, or any consequences from the application of the information in these publications and make no warranty, expressed or implied, concerning the currency, completeness, or accuracy of the publication's contents. It would be best not to rely on this information as a substitute, nor does it replace professional medical advice, diagnosis, or treatment.   

I, Katie Marshall, am not a doctor or medical provider and do not provide medical advice. Readers are advised to research and make decisions in partnership with their healthcare provider.   

If you are pregnant, nursing, have a medical condition(s), or take any medication(s), please consult your family physician.   

Always seek the advice of your family physician or other qualified healthcare providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you read on my social media pages or websites.   

If you have a medical emergency, call your family physician, go to the nearest emergency department, or call 911 immediately. Reliance on any information provided by MBK Cultivate Skin & Nutrition Wellness or Katie Marshall presenting content for publication to these social media pages or websites is solely at your own risk. Administrators and Moderators are not liable for your actions.   

Health Canada & FDA Disclaimer:   

Health Canada or the Food and Drug Administration has not evaluated the advice and statements on this page.