Good Carbs vs Bad Carbs: How to Tell The Difference

An image showing good carbs vs bar carbs
Image credit:

This article is all about telling the difference between good carbs and bad carbs, including:

  1. What Exactly Are Carbs?
  2. Carb Controversy: Why Carbs Are So Confusing
  3. Why Is My Doctor Telling Me To Cut Out All Carbs?
  4. Practical Tips: How to Identify “Bad Carbs” and Foods to Avoid
  5. Is It Healthy To Cut Out All Carbs?

When you’re trying to control your blood sugar, these days it seems like everyone wants to throw an opinion about carbs at you.

“You should never eat carbs!” Shout the online carb cutters and keto fans. 

“Avoid carbs at ALL costs” your doctor says. 

“But wait, don’t veggies and fruits contain carbs?” your intuition chimes in.

It’s time to get the full story on carbs so you have the confidence to best manage your blood sugar and health.   

It’s likely that what you’ve been told so far about “carbs” is oversimplified and misguided. When it comes down to the question of “are carbs bad or good?” the answer really isn’t as cut-and-dried as you’ve been led to believe. While some carbs should be avoided at all costs, there are others that you should be getting MUCH more of in your diet. 

In fact, there are even certain plant-based carbs that can help significantly in controlling your blood sugar

Surprised? We thought you might be. Which is why we’ve compiled a thorough guide to help classify carbs into the “good” or “bad” camp, and empower you to make the best choices about which carbohydrates to include in your diet — yes, even if you’re worried about your blood sugar. Let’s dig in. 

What Exactly Are Carbs?

An illustration of a carbohydrate molecule

Take away all of the preconceived notions that you have about carbs, and let’s start from the beginning.

Short for carbohydrate, carbs are 1 of the 3 main macronutrients that humans need to survive — the others being protein and fat. Almost all foods have carbs in them. Usually, when food is referred to as a “carb” that simply means it contains more carbohydrates in its profile than either of the other two macronutrients. 

For this reason, a “carb” can mean pasta, a bowl of sugary cereal, or even green beans.

When you eat and digest carbohydrates, they are converted into glucose, which fuels the body and brain, and gives you energy. 

There are 2 primary types of carbs, simple carbs and complex carbs. Let’s take a look at the differences:

Simple Carbs (Also Known As Refined Carbs or Sugars) 

  Simple carbs are the ones that give carbs a bad name.

Simple carbs (including sugars and refined grains that have been stripped of all nutrients) digest very quickly. When you eat them they spike your blood sugar levels, and they can have long term effects on your body’s ability to deal with excess insulin and glucose in your blood — this is called insulin resistance. 

“Don’t write off all carbs as being bad. Start getting some resistant starch into your eating plan and reap the benefits!” – Diabetes Self-Management

Eating too much sugar has been linked to weight gain, heart disease, and diabetes. 

These sugars are the carbs you definitely want to limit or avoid in your diet. Especially if you’re concerned about your blood sugar levels or weight loss.

These simple carbs include foods like:

  • Sweets — cookies, cakes, pies, pastries
  • Processed or refined foods — think anything with white flour, like bread or pretzels, or refined pasta
  • Natural sugars — like honey, cane sugar, maple syrup or coconut sugar
  • Fruit juices — canned, jarred, or even fresh squeezed

Complex Carbs (Also Known As Whole Carbs)

Complex carbs include fibers and starches that are ALSO considered carbs, but they aren’t sugars. These types of carbs take longer for the body to digest, so they don’t spike blood sugar in the same way that sugars do. 

When it comes to these types of carbs, the more complex they are, the better they are for blood sugar management. The closer to a whole food they are, the better. And the more fiber they contain, the better.

An image of a magnifying glass over a nutrition panel

Let’s break this group down a little further:


Starches are those plant-based foods that usually cause the most confusion when it comes to blood sugar regulation. 

Starches can be harmful or helpful depending on the type and what form they are in. For example, oats are a starch, and they can help control blood sugar and blood cholesterol.

“There is a type of starch that diabetics can benefit from — resistant starch.” — NDTV Food

Some starches can be eaten in moderation without too much of a negative effect on blood sugar. These questionable starches include foods like potatoes and whole grain bread. But if you eat an entire plate full of potatoes, your blood sugar will likely be negatively impacted. If you eat a small portion of these carbs combined with fat and protein, you will be less likely to experience a spike in glucose. Each individual person responds differently depending on their unique blood sugar response. 

Starches include foods like:

  • Whole wheat pasta
  • Potatoes
  • Whole grain bread
  • Corn 
  • Oats
  • Brown or white rice


Fiber is the undisputed heavyweight champion, the king of all healthy carbs. 

Fiber is just flat out amazing for your health ESPECIALLY if you have insulin resistance or diabetes. 

These kinds of carbs have amazing health benefits. Particularly prebiotic fibers like resistant starch

Fiber and resistant starch are incredibly beneficial for several reasons:

  • They help you to feel full (which means you’re less likely to overeat and weight loss becomes easier)
  • They (specifically prebiotic fibers like resistant starch) help strengthen your gut microbiome (which is crucial for blood sugar control, immune response, and even mood)
  • They help control “bad” cholesterol in the blood (which leads to better heart health)
  • They help improve digestive health and bowel function (keeping you regular and healthy)

Fiber is found in healthy plant foods like:

  • Vegetables — any leafy greens or broccoli
  • Fruits — like apples, berries, or green unripened bananas
  • Beans
  • Nuts
  • Legumes

The Importance of Fiber: What the Science Says

When you look at the scientific evidence, fiber-rich carbs are pretty much all-stars of healthy foods. In fact, studies show that:

Carb Controversy: Why Carbs Are So Confusing

An image of a woman looking confused

Somewhere along the way, all carbs got lumped together with the simple yet inaccurate message that ALL carbs are bad for your health and blood sugar control. This oversimplification has become widespread and just simply isn’t the truth.

We’re human, and we’re busy, and our brains prefer simple messages.

“Dietary resistant starch might alter gastrointestinal tract function in a manner that improves human health, particularly among adults at risk for diabetes. ” – PubMed

In reality, though —  the term “carb” is not really that meaningful or helpful when it comes to making healthy food choices (especially for blood sugar control). Because there’s such a VAST difference between the “Bad carbs” (like sugar) and the “Good carbs” (like fiber). So it definitely doesn’t make sense to lump all carbs together and treat them the same way.

Some “carbs” life fiber are CRITICAL to helping get your blood sugar levels under control naturally. These are the types of carbs that you need to get MUCH MORE of in your diet, especially if you have elevated glucose levels.

Why Is My Doctor Telling Me To Cut Out All Carbs?

So if there’s all this evidence that fiber, and especially prebiotic fiber like resistant starch — which are technically carbs — are extremely beneficial for you, why is your doc recommending that you cut carbs completely from your life?

A gif of confusion

For starters, many primary care physicians receive limited training and education in nutrition science, and generally have to keep their recommendations short. Which means they often offer a quick “stay away from carbs” rather than going deeper to understand and explain the nuances and importance of complex carbs like fiber vs. simple carbs to their patients.

Also the medical industry historically takes a looooong time to catch up to shifts in dietary recommendations — which means we sometimes have to take matters into our own hands in order to get blood sugar under control now.

But What About Keto and Low-Carb?

There’s a lot of talk about the keto diet for blood sugar management, and for some people, this method of extreme carbohydrate restriction can work for weight loss and improved blood sugar levels. 

But if you’ve ever tried keto and found it completely impossible to adhere to, or tried it and got tired of the headaches and low energy levels…you’re not alone. 

While everyone is unique and may have different experiences with certain diets, the bottom line is that when you significantly restrict all carbs (especially complex carbs like fiber and resistant starch), chances are that you’re depriving your body of critical nutrients and limiting the diversity of your gut microbiome.

And — if you have found success with a keto diet, there’s great news…The fiber that’s in most complex carbs actually doesn’t count towards your net carb count, which means you can STILL enjoy some of these superfoods completely guilt free. 

Practical Tips: How to Identify “Bad Carbs” and Foods to Avoid

While it may take some time for the general public and even physicians to fully understand the differences in the types of carbs, we want to help make it easy to understand how to effectively manage carbs in your diet.

One way to identify how many “bad carbs” are in any given food, is to avoid food with a high net carb count. This simple net carb equation can be helpful:

Total carbs – fiber – non-digestible carbs = Net Carbs

For example, take a look at the Supergut label below:

An image showing a carb equation

Here, you see we’ve taken the total carbs (41g), subtracted the fiber (15g) and the nondigestible carbs (these include things like allulose or sugar alcohols — things your body can’t digest and therefore don’t count as carbs) (20g) and ended up with only 6g of net carbs.

This equation can also apply to foods like beans, fruits, and vegetables — basically any food that contains fiber. 

Is It Healthy To Cut Out All Carbs?

So, to bring it all together, it’s NOT ideal to cut ALL carbs from your diet.

While it’s true that digesting carbs raises blood glucose and prompts the release of insulin — avoiding them altogether is well-meaning but misguided advice (especially if you’re trying to get blood sugar issues under control).

As a reminder, the most practical way to identify foods that contain “good carbs” is by figuring out its fiber content. 

And you should absolutely get a LOT more of those healthy, fiber-rich carbs like resistant starch that are so efficient at getting your blood sugars down, and produce all kinds of incredible health benefits.

Everyone should aim to eat about 30g of fiber a day…and most Americans get less than half that. Once you’ve determined if a carb is full of fiber-y goodness, you can then use the Net Carb count (the total carbs minus the fiber and nondigestible carbohydrates) to get a better idea of how many “bad carbs” are in a food. 

We hope this guide has been beneficial. If you’re looking for more great health-focused content, hop over to our blog and check out the other resources there. 



  • At Supergut, we're committed to help you balance your gut and optimize your metabolism, wherever you are in your quest for better health.

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like

Author Bio: Supergut Team

At Supergut, we're committed to help you balance your gut and optimize your metabolism, wherever you are in your quest for better health.


Leave a Reply

Your email address will not be published. Required fields are marked *