Fiber gets talked about constantly when it comes to blood sugar—but what does it actually do? Let's unpack soluble and insoluble fiber, “net carbs,” high-fiber packaged foods, and practical ways to get more fiber without turning meals into a math assignment.
Fiber has excellent public relations.
We're told to:
Eat more fiber.
Choose high-fiber bread.
Add chia seeds.
Eat beans.
Leave the skin on everything.
Buy the tortilla containing a quantity of fiber that seems to defy the laws of agriculture. 😂
And if you're navigating insulin resistance, prediabetes, or diabetes, you've probably also encountered claims that fiber somehow “cancels out carbs.”
So what is fiber actually doing?
Quite a lot, as it turns out.
But it isn't performing carbohydrate magic.
Fiber is itself a type of carbohydrate found primarily in plant foods. Unlike sugars and starches, dietary fiber isn't fully broken down and absorbed in the small intestine in the same way. Different types of fiber can influence digestion, bowel function, cholesterol, satiety, and the way glucose enters the bloodstream.
So today, we're giving fiber its own Learn post.
No food fear.
No fiber Olympics.
And absolutely no requirement that you begin sprinkling chia seeds onto foods where chia seeds have no business being.
Let's learn. 💚
First: Fiber Is a Carbohydrate
Yes.
Fiber is a carbohydrate.
Carbohydrates generally include three major categories:
Sugars
Starches
Fiber
But our bodies don't handle all three identically.
Sugars and digestible starches are broken down and absorbed, contributing glucose that can affect blood sugar.
Dietary fiber largely passes through the small intestine without being digested and absorbed in the same way. Some fibers are later fermented by bacteria in the large intestine.
So saying:
“Fiber is a carbohydrate.”
and
“Fiber behaves differently from sugars and starches.”
isn't contradictory.
Both can be true.
Nutrition does this to us a lot. 😂
Soluble vs. Insoluble Fiber
You've probably seen fiber divided into two categories:
Soluble Fiber
Soluble fiber dissolves in water. Some soluble fibers form a gel-like material in the digestive tract, which can slow digestion and influence glucose absorption and cholesterol.
Foods containing soluble fiber include things like:
- Oats
- Beans
- Peas
- Apples
- Brussels sprouts
- Avocado
Insoluble Fiber
Insoluble fiber doesn't dissolve in water in the same way and helps add bulk to stool and support regular bowel function.
You'll find it in foods including:
- Whole grains
- Wheat bran
- Nuts
- Seeds
- Many fruits and vegetables
The CDC notes that both forms have important roles in health.
But here's the part I don't want you worrying about:
You don't need to micromanage them.
Most plant foods aren't walking around containing exactly one isolated type of fiber.
Eating a variety of fruits, vegetables, legumes, whole grains, nuts, and seeds naturally exposes you to different types of dietary fiber.
Nobody needs to sit at dinner wondering:
Have I adequately represented both fiber factions on this plate?
😂
What Does Fiber Have to Do With Blood Sugar?
This is where fiber becomes particularly relevant to insulin resistance and diabetes.
Because fiber isn't digested like sugars and starches, it doesn't raise blood glucose in the same way. Certain soluble fibers can also slow digestion and the absorption of nutrients, which can help moderate how quickly blood glucose rises after eating.
Higher-fiber eating patterns can also support digestive health and are associated with cardiovascular benefits—particularly relevant because cardiovascular health and metabolic health often overlap.
But there's a phrase I want to be careful with:
Fiber Does NOT “Cancel” Carbohydrates
This language is everywhere.
Someone sees:
30g total carbohydrate
and
10g fiber
and concludes that the fiber somehow entered the food and neutralized ten grams of carbohydrate.
That's not really what's happening.
Remember:
Fiber is already included within Total Carbohydrate on a U.S. Nutrition Facts label.
It's then listed underneath so you can see how much of that total comes from dietary fiber.
Fiber's presence tells us something meaningful about the food.
But the useful takeaway isn't:
Fiber made the other carbs disappear.
It's:
This food contains carbohydrate, including fiber, and those carbohydrates aren't all handled identically by the body.
That's a much more accurate foundation.
So...What Are “Net Carbs”?
Ah yes.
Net carbs.
The number printed in enormous letters on the front of a package while the Nutrition Facts panel quietly waits around the back. 😂
“Net carbs” generally refers to a calculation that subtracts dietary fiber—and sometimes some or all sugar alcohols—from total carbohydrate.
You may see something like:
Total Carbohydrate – Fiber – Certain Sugar Alcohols = “Net Carbs”
Here's the important distinction:
The FDA Nutrition Facts label requires Total Carbohydrate and Dietary Fiber to be reported according to federal labeling rules. The FDA's standard Daily Value for dietary fiber is currently 28 grams on a 2,000-calorie reference diet.
“Net carbs,” however, is not one of the standard mandatory nutrient lines on that Nutrition Facts panel.
And different fibers and sugar alcohols aren't necessarily handled identically by the body.
So rather than treating a front-of-package net-carb claim as the only number that matters, I prefer starting with the actual Nutrition Facts label.
Look at:
Total carbohydrate.
Dietary fiber.
Added sugars.
Serving size.
And, when useful, the ingredient list.
Then consider the food within your overall meal and your individual needs.
Much more informative than letting one giant number on the front of the package make the entire decision for you.
Does 30 Grams of Fiber in One Tortilla Mean It's Better?
Not automatically.
And yes, Tuesday's wrap inspired this section. 😂🌯
Food manufacturers can add isolated or manufactured fibers to foods such as tortillas, breads, bars, cereals, drinks, and other products.
Those foods can absolutely fit into someone's eating pattern.
If you enjoy a high-fiber tortilla and it works well for you?
Eat the tortilla.
But a product containing an enormous amount of fiber isn't automatically superior to every product containing less.
There are other things to consider:
Does it taste good?
Do you enjoy the texture?
How does your digestive system respond to it?
What else is in the product?
What are you eating with it?
Is it affordable and accessible?
And perhaps most importantly:
Do you actually want it?
A traditional tortilla you enjoy isn't nutritionally worthless because another tortilla managed to fit half a day's fiber into one wrap.
More Fiber Isn't Always Better
This is an important one.
Fiber is beneficial.
That doesn't mean the goal is to consume as much fiber as physically possible.
Increasing fiber too quickly can cause:
- Gas
- Bloating
- Cramping
- Constipation
- Diarrhea
- General gastrointestinal unhappiness
The CDC and NIDDK both recommend increasing fiber gradually rather than making a dramatic jump, and adequate fluids are important as fiber intake increases.
Which brings me to...
Please Don't Go From 10 Grams of Fiber to 35 Overnight
Your digestive system would like to be included in this decision. 😂
Imagine someone discovers fiber on Monday.
Tuesday morning:
High-fiber cereal with chia seeds.
Snack:
Pear and almonds.
Lunch:
Lentil soup and a high-fiber tortilla.
Snack:
Fiber bar.
Dinner:
Black beans, brown rice, Brussels sprouts, and avocado.
And then Tuesday night they're Googling:
“Why am I shaped like a parade balloon?”
😂
The problem isn't that those foods are bad.
The problem may simply be that the digestive system experienced a very large change very quickly.
If your current intake is relatively low, gradually introducing more fiber-rich foods gives your gastrointestinal system time to adjust.
NIDDK specifically advises adding fiber a little at a time; adequate liquids help fiber work properly as well.
No need to become one with the lentil overnight.
How Much Fiber Do We Actually Need?
There isn't one perfect number for every person.
General recommendations vary by age, sex, and energy needs. Current U.S. guidance commonly puts adult needs around 22–34 grams per day, depending on age and sex. The FDA's Daily Value used on Nutrition Facts labels is 28 grams per day, based on a 2,000-calorie reference diet.
You'll also encounter the broader benchmark of roughly 14 grams per 1,000 calories used in dietary reference guidance.
But I don't want that turning into:
“I ate 26 grams today instead of 28, therefore I failed fiber.”
No.
These numbers are reference points, not daily report cards.
Your individual needs may also differ because of age, energy intake, digestive conditions, medications, medical care, or other factors.
For individualized recommendations, especially if you have gastrointestinal problems or another medical condition that affects what you can comfortably eat, a registered dietitian or other qualified healthcare professional can help.
Where Does Fiber Actually Come From?
The nice thing about fiber is that you don't need a specialty product to find it.
It's spread throughout ordinary plant foods.
Beans, Peas & Lentils
Think:
Black beans.
Chickpeas.
Kidney beans.
Lentils.
Split peas.
These can bring substantial fiber while also contributing protein, minerals, and carbohydrates.
Whole Grains
Foods such as:
Oats.
Barley.
Whole wheat.
Brown rice.
Quinoa.
Whole-grain breads and cereals.
The amount varies considerably from food to food, so “whole grain” doesn't automatically tell you the exact fiber content.
Fruit
Berries.
Pears.
Apples.
Oranges.
Peaches.
Bananas.
And plenty more.
Fruit brings fiber alongside water, naturally occurring sugars, vitamins, minerals, and plant compounds.
Vegetables
Brussels sprouts.
Broccoli.
Carrots.
Peas.
Winter squash.
Leafy greens.
Potatoes.
Different vegetables provide very different amounts, but variety is useful.
Nuts & Seeds
Chia seeds.
Flaxseed.
Almonds.
Pecans.
Walnuts.
Pumpkin seeds.
Sunflower seeds.
These also bring different combinations of fats, protein, vitamins, and minerals.
The CDC and NIDDK similarly point to fruits, vegetables, whole grains, legumes, nuts, and seeds as useful dietary fiber sources.
Look at What We Ate This Week
This is my favorite part because we didn't intentionally design this week's recipes around fiber.
It just happened naturally.
Thursday
Our Honey-Mustard Sheet-Pan Chicken included Brussels sprouts and potatoes.
Friday
Our Savory Pumpkin Cheddar Mini Muffins included pumpkin, whole-wheat flour, and pumpkin seeds.
Saturday
Brown Butter Pear & Walnut Oat Crisp gave us pears, rolled oats, walnuts, and almond flour.
Sunday
Wild Rice & Mushroom Stuffed Acorn Squash brought acorn squash, wild-rice blend, mushrooms, celery, cranberries, and pecans.
Monday
Apple-Cinnamon French Toast Bake included apples, oats, whole-grain bread, and pecans.
Tuesday
Our Turkey, Apple & Cheddar Harvest Wrap brought apple, greens, pecans, and a whole-grain tortilla.
None of those meals required us to sprinkle fiber powder over dinner.
😂
That's what I mean when I talk about building dietary patterns rather than chasing individual nutrients.
Fiber can show up naturally when a variety of plant foods regularly show up in our meals.
Do I Need to Leave the Skin on Everything?
Considering this week's recipes, apparently we need to settle this. 😂
Apple skin.
Pear skin.
Potato skin.
Acorn squash skin.
Yes, the skins of many fruits and vegetables contain fiber and plant compounds, and keeping edible skins can increase the amount retained in the food. The CDC lists the skins of many fruits and vegetables among sources of insoluble fiber.
But:
You are allowed to peel food.
If you hate apple peel in baked apples?
Peel it.
If potato skin bothers you?
Peel the potato.
If you're eating roasted acorn squash and don't want the skin?
Scoop out the flesh.
A peeled apple does not transform into candy.
A peeled potato does not become nutritionally empty.
Sometimes keeping the skin makes sense.
Sometimes texture preference wins.
Whole Foods vs. Added Fiber
This deserves some nuance too.
Foods naturally containing fiber—beans, vegetables, fruit, whole grains, nuts, and seeds—usually bring fiber packaged alongside many other nutrients and food components.
Packaged foods can also contain isolated or added fibers.
That doesn't automatically make them bad.
Sometimes they're useful.
Sometimes they're convenient.
Sometimes they taste great.
And sometimes a high-fiber packaged product may cause digestive discomfort for someone who isn't accustomed to that particular fiber or quantity.
The Nutrition Facts label can help you see exactly how much dietary fiber you're getting per serving; FDA guidance considers 20% Daily Value or more per serving high and 5% or less low.
That information is useful.
But it still doesn't tell you whether you're going to like the food or how your digestive system will respond to it.
Your body gets a vote too.
Do I Need a Fiber Supplement?
Not necessarily.
Many people can get fiber through food.
Fiber supplements can be useful in certain circumstances, but different supplements contain different types of fiber and may be recommended for different reasons.
If you're considering one because of constipation, digestive symptoms, diabetes management, cholesterol, or another medical concern, it's worth discussing with your healthcare professional rather than assuming that the biggest scoop of fiber powder is automatically the solution.
Especially because...
We've already established what happens when someone suddenly decides fiber is their entire personality. 😂
A Better Way to Think About Fiber
Instead of asking:
“How do I get the maximum possible amount of fiber into every meal?”
Try:
“Where can plant foods I actually enjoy fit naturally into the way I already eat?”
Maybe that's:
Adding beans to chili.
Putting berries on oatmeal.
Choosing whole-grain bread sometimes.
Eating an apple.
Adding roasted Brussels sprouts to dinner.
Tossing pecans onto yogurt.
Making lentil soup.
Adding vegetables to pasta.
Using chia seeds because you genuinely like chia pudding.
Choosing brown rice sometimes.
Choosing white rice other times.
Eating a regular tortilla because it's the tortilla you actually like.
No single food determines whether your diet contains enough fiber.
It's the pattern that builds over time.
And Fiber Doesn't Have to Become Another Food Rule
This might be the most important part of today's article.
Nutrition education is supposed to give us more useful information.
It shouldn't simply give us a new collection of foods to fear.
We've already seen what happens when carbohydrates become:
“Carbs are bad.”
Then protein becomes popular and suddenly:
“Everything must contain 30 grams of protein.”
Fiber can easily become the next version:
“If it doesn't have enough fiber, don't eat it.”
We're not doing that either.
White rice can still be dinner.
Regular pasta can still be dinner.
White bread can still make a sandwich.
Dessert doesn't need chia seeds.
And your tortilla doesn't need to contain enough fiber to upholster a sofa. 😂
Fiber matters.
But so do:
Taste.
Culture.
Convenience.
Budget.
Digestion.
Variety.
Individual medical needs.
And enjoying what you eat.
The goal isn't nutritional perfection.
It's learning enough about food that you can make informed choices without becoming afraid of it. 💚
The Takeaway
Fiber is a carbohydrate found primarily in plant foods, and different types of fiber can support blood-glucose management, digestive health, and cardiovascular health.
Most adults are generally advised to get somewhere around 22–34 grams per day, with individual needs varying; the FDA Daily Value on food labels is 28 grams.
But you don't need to obsessively count every gram.
Build variety.
Include plant foods you enjoy.
Increase fiber gradually if you're currently eating very little.
Drink adequate fluids.
Pay attention to how your body responds.
And remember:
Fiber doesn't cancel your carbs.
More isn't automatically better.
You don't have to leave every peel on.
And...
You are allowed to eat the tortilla you actually like. 😂🌯💚
Sources & Further Reading
For readers who want to explore the guidance behind this article:
CDC — Fiber: The Carb That Helps You Manage Diabetes
FDA — Daily Value on the Nutrition and Supplement Facts Labels
FDA — How to Understand and Use the Nutrition Facts Label
NIDDK — Eating, Diet & Nutrition for Constipation
Individual nutritional needs and blood-glucose responses vary. Eat Against Resistance provides recipes and general nutrition information and isn't a substitute for individualized medical or professional nutrition advice.
Making insulin resistance easier, one meal at a time. 💚