are carbs bad for you

Are Carbs Bad for You?

There’s a lot of talk about carbohydrates these days, and often times it’s pretty negative. But are all carbohydrates bad for people with diabetes and prediabetes? Some ketogenic, low-carbohydrate diet, or dare I say, carnivore diet advocates would have you believe that no carb is a good carb.

You don’t have to travel far to hear a diet guru claiming that carbohydrates are to blame for:

  • Obesity
  • Inflammation
  • Insulin resistance and diabetes
  • And everything else wrong with your health

Their solution? Eliminate them.

Well, not only is this:

A) Easier said than done.

It’s also:

B) Confusing, unnecessary, and imprecise.

So, let’s take a closer look, to answer the question “are all carbs bad for you?”

The Anti-Carb Craze is Nothing New

carbohydrate caution

The elimination model outlined above should look familiar. After all, the anti-carb craze is no different than the anti-fat craze that came before it. And, as we found out, not all fat is bad. Certain types are horrible (looking at you trans fat), and certain types should be limited in certain populations (saturated), but overall, all fat is not the evil substance some once made it out to be.

So, it should come as no surprise that not all carbohydrates are bad either.

Yes, some carbohydrates are piss poor for your health and should be minimized. But many are even good for you, and part of a healthy diet, even if you have prediabetes or diabetes.

For example:

  • A 2013 study in the British Medical Journal showed that eating fruits such as apple, grapes and blueberries significantly lowered the risk of developing type 2 diabetes.
  • In a separate 2020 study, the British Medical Journal also found that people who ate the most whole grains per day had a 29% lower risk of developing diabetes.

Yeah, those are both health benefits associated with eating carbohydrates.

So, rather than cutting the cord on all carbohydrates, I think it’s imperative to better understand the different types of carbohydrates, how they break down into sugar in your bloodstream, and then how to pair them with other macronutrients like protein to get a more stable blood sugar response. Then you can make better dietary choices that fit your lifestyle, goals, and preferences, without having to follow dietary dogma.

So, Why Do Carbohydrates Get Such a Bad Rap?

There are three macronutrients: protein, carbohydrates, and fat.

Fat and carbohydrates are primarily used for energy. Protein is largely used for tissue repair and growth. And, carbohydrates are the macronutrient that will have the most effect on increasing your blood sugar.

How Your Body Reacts to Sugar

When your blood sugar spikes, your pancreas releases insulin. The insulin allows the sugar in your blood to enter cells in your body so it can then be used as fuel or converted and stored as fat. This is all good, and business as usual.

But, when your blood sugar is chronically high, and your insulin is consistently elevated, that’s where you get into trouble.

Over time, if your body is exposed to chronically high insulin, it compensates by becoming less sensitive to insulin. So, insulin starts to become less effective at clearing sugar from your blood, and your blood sugar readings begin to rise. This is how we can progress to prediabetes, and then type 2 diabetes.

Sounds scary right? Well, before you start clearing carbohydrates from your kitchen, here’s what you need to know…

Not All Carbohydrates are Created Equal

As it turns out, carbohydrate is a large umbrella term, that has more to do with their chemical structure than how they are broken down in your body.

All carbohydrates have one commonality. They are composed of sugar molecules. And, for the most part, they fall into three categories.

  • Simple carbs (sugars)
  • Starch
  • Fiber

How Does Your Body React to Simple Carbs?

Simple sugars are carbohydrates that consist of one sugar molecule, or two sugar molecules bound together. Your body quickly breaks these molecules apart and rapidly absorbs the glucose, causing the most significant increase in blood sugar levels.

Glucose is an example of a single sugar molecule, and also the molecule we are measuring when we take our blood sugar.


Sucrose, AKA table sugar, consists of two sugar molecules bound together, glucose + fructose.


Simple carbs don’t have many or any binds to break, in order for your body to absorb them. They are the purest form of carbohydrates. So, they are rapidly absorbed and cause an immediate increase in your blood sugar.

It’s not as simple as categorizing carbohydrates into buckets of good carbs and bad carbs. But, if you’re worried about your blood sugar, these are the foods you need to limit the most, especially in the form of added sugars.

Foods that are high in simple carbs and added sugars include include desserts, fruit juices, soda drinks, and candy. This also includes sweeteners such as honey, agave, and syrup.

How Does Your Body React to Starch?

Starch is a type of complex carbohydrate that is composed of long strings of glucose molecules bound together. When we eat foods high in starch, the enzymes in our gut break them down into individual glucose molecules, which are then absorbed.


To absorb starch, your body first needs to break the glucose molecules apart. So, they take longer to digest than simple sugars, and have less of a dramatic effect on your blood sugar. However, since starch is essentially a string of glucose molecules, it will still raise your blood sugar. So, it’s important to be aware of that and to control your portions.

Starchy plant foods include potatoes, sweet potatoes, yams, corn, and beets. But, starchy foods also include refined grains like rice, white bread, and refined flours.

Even whole grains like wheat and oats are considered a starch, but they are higher in dietary fiber than processed carbs, and we’ll talk about why that’s important next.

How Does Your Body React to Fiber?

And then there’s dietary fiber – which is unique because it isn’t digested by us at all. It actually passes through your body largely intact, because we don’t have the enzymes necessary to break its glucose molecules apart. However, it does help feed the good bacteria in your gut, thus supporting a healthy digestive system.

An example of a fiber molecule is cellulose, shown below.


Fiber, like cellulose, is found in plants. It helps protect them and give them structure. And, since we can’t digest fiber it does not increase blood sugar levels the way that starch or simple carbs do. Instead, when you include fiber with your meals, it helps to slow the absorption of sugar. It also promotes satiety, AKA a sense of fullness, thus preventing us from eating too much.

Fiber is usually just one component of the food we eat. For instance, fruit has fiber in it as well as natural sugar, but since it’s packaged with fiber, the sugar is more slowly absorbed. Or, take the example of white rice vs. brown rice. Both of these foods are considered starches. But, brown rice has more fiber in it, which also helps slow the increase in blood sugar levels.

Another similar example is white bread, vs whole grain bread.

In this way, choosing whole foods that are high in fiber can be helpful for controlling blood sugar levels. It can also help reduce cholesterol. Some examples of high fiber, whole foods includes fruits, vegetables, nuts, seeds, whole grains, and legumes like beans or lentils.

Choosing Your Carbohydrates Carefully

The point is, carbohydrates are more than just generic ‘bad stuff’ that you need to avoid if you want to stay healthy and keep your blood sugar in check. Instead of being carb averse, you need to be carb conscious.

When you look at a carbohydrate, stop and ask yourself, “what type of carbohydrate is this? Does it consist of a starch, added sugars, or high-fiber food?”

As we already discussed, these types of carbohydrates are each broken down and absorbed differently. You don’t need to run away from all of them, you just need to be aware, and intentional with which carbs you choose and how much of them you eat.

So, based on what we’ve learned, let’s identify what carbohydrates to avoid, limit, and embrace.

What Carbohydrates Should You Avoid?

carbs to avoid

If you’re looking for a carbohydrate to avoid, eliminate the simple sugars contained in processed foods. Like salt, sugar is included in a lot of foods because it makes them more palatable. Even dried or canned fruit often has added sugar, which is in addition to the already naturally occurring sugar.

Keep in mind, the simpler the sugar is and the more removed from its original source, the worse effect it’s going to have on your blood sugar. Orange juice for example sounds like it would be good for you because we’re often told to eat more fruit and vegetables. But, without the fiber of the original orange, that orange juice will have a similar effect on your blood sugar as a coca-cola.

Don’t get me wrong, I think it’s okay to enjoy a sweet treat or dessert on occasion. But, do it in moderation, and eat mindfully – stop, and eat it slowly, so you can fully enjoy each bite.

For help practicing mindful eating, check out this 5-Minute Mindful Eating Exercise, using chocolate.

What Carbohydrates Should You Limit and Moderate?

carbs to moderate

You don’t need to completely eliminate starches and grains from a your diet. But it’s a good idea to be aware of what foods are starches and to limit your portion sizes accordingly.

While they don’t contain sugar directly, starchy foods are quickly broken down into sugar molecules by your body. So in order to control the effect on your blood sugar, it’s important to moderate how much of these foods you eat.

Processed grains like white bread, pasta, and white rice are starches that are more quickly absorbed than whole grains like oats, farro, quinoa, or brown rice. Whole grains are also classified as starch, but they contain more fiber, which slows the breakdown and absorption of glucose.

When choosing a starch, try to choose a whole grain or whole food option. The glycemic index can also be helpful for identifying which starches have the least impact on blood sugar. Typically, the more processed a food is, the higher it is on the glycemic index.

What Carbohydrates Should You Embrace?

good carbs to embrace

The best carbohydrates for blood sugar control are going to be ones that are high in fiber. And nothing quite beats non-starchy vegetables when it comes to high-fiber foods.

That’s why non-starchy vegetables are the most blood sugar-friendly carbohydrate for a balanced diet. Packed with fiber, they are metabolized into sugar less readily, and they aid digestion.

But, not only do they provide a ton of fiber, they also contain essential vitamins and minerals that your body needs for optimal health. Plus, you’ll get more bang for your caloric buck since they are low in calories compared to processed foods, and they make you feel more full.

Non-starchy vegetables include broccoli, brussels sprouts, kale, spinach, peppers, mushrooms, tomatoes, and all sorts of other colorful produce.

Pair Your Carbs With Protein for Improved Blood Sugar Control

It’s also important to not only choose the right kind of carbs, but to pair them with an adequate amount of protein. Protein helps slow down absorption and keeps you more satisfied after a meal.

Eating protein helps slow the absorption of carbohydrates into your bloodstream in a process called “the protein-induced glucose response”. This reduces the amount of sugar released at one time and helps stabilize blood glucose levels.

Research Supports Pairing Carbs with Protein

In a study done by the American Diabetes Association, researchers found that you can slow the metabolization of simple carbohydrates when eating the protein and vegetables in your meal first. In the study, participants were fed orange juice and bread, and then given the rest of their meal which consisted of a chicken breast, salad, and steamed broccoli (non-starchy vegetables). The participants were then fed the same meal a week later in reverse order, eating the bread and orange juice last.

When participants ate the protein and vegetables first, they had 29% lower glucose levels 30 minutes after the meal, compared to when they ate the bread and sugar first. Two hours after the meal, their glucose levels were still lower.

So, how can you apply this? Simple. Whenever you eat a starch or simple carbohydrates, try to also include a protein and a high-fiber non-starchy vegetable to help dampen the glucose response.

What proteins should you use? Aim for lean proteins like grilled chicken or turkey, fish, eggs, cottage cheese, or greek yogurt. Or choose from plant-based protein snacks like hummus, beans, nuts, or tofu.

What About Whey Protein?

The studies outlined above suggest it’s a good idea to pair protein with your carbs, but what about protein supplements like whey? Can whey protein also help slow the glucose response from carbohydrate containing foods? One study from 2009 suggests that yes, they can.

Like the previous study, this one showed that when whey protein was consumed prior to a high-carb meal, the blood glucose response to that meal was reduced. In addition, the study found that whey protein increased the amount of CCK and GLP-1, which are two hormones that help slow stomach emptying. This causes the carbohydrates to more slowly pass into the small digestion and slowing the absorption rate.

How to Put it All Together Using the Diabetes Plate Method

The bottom line is that not all carbs are bad. As long as you choose the right kind of carbohydrates and pair them with an adequate amount of protein and non-starchy vegetables, you’ll be able to better control your blood sugar levels.

One way to do this is to use the Diabetes Plate Method. This method is simple.

  1. Take a 9-inch diameter plate.
  2. Draw an imaginary line down the middle horizontally, splitting the plate into two halves.
  3. Then draw a second imaginary line horizontally to split one half into two quarters.

You’ll end up with something like this:

diabetes plate method

Then, you’ll choose the following for each portion:

  • 1/2 of the plate should be non-starchy vegetables
  • 1/4 of the plate is for starchy vegetables or whole grains
  • 1/4 of the plate is for protein

Notice that there’s no portion allocated for added sugars or refined grains. That’s because they should be minimized.

Carbs are Part of a Healthy Diet

In summary, you don’t need to be afraid of carbohydrates. But you do need to understand them, so you can make carb-conscious decisions based on your health goals. When you combine this knowledge, with awareness, it allows you to take sustainable actions that help you create a healthy diet and meal pattern that lasts for the long term.

If you’re interested in learning how to apply these principles into your own life, contact me. I help clients develop healthy lifestyle changes that last for the long haul, while reducing their risk for chronic diseases, like diabetes.

Learn more about how a dietitian can help with prediabetes.

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