This, and all of your burning carb questions answered by experts living with diabetes.

Carbohydrates can feel confusing, especially if you have diabetes. Some people think they shouldn't eat any carbs, but that just isn't true. However, it's important to learn about how carbs can impact your blood sugar, figure out the healthiest carbs to eat and learn how to make them work in your diet. We tapped several experts to answer every carb question you have, from the keto diet to fiber.

What exactly are carbs?

When you hear "carbohydrates," think "plant power," says Toby Smithson, M.S., RDN, LD, CDE (PWD type 1), Founder,; author, Diabetes Meal Planning and Nutrition for Dummies. On a basic level, carbs are the sugars, starches, and dietary fibers that plant foods (like grains, vegetables, beans, and fruits) make using energy from the sun. Carbs serve as a major fuel source for our bodies, alongside the other macronutrients: protein and fat. Carbs are found in lots of different foods—from fruits and vegetables to brownies and cookies. Choose complex carbs more often—from whole grains, fruits and vegetables—and simple carbs—like sugar and white rice—less often.

hands working a nice large bite of spaghetti
Credit: Getty Images / Jonathan Knowles

How do carbs impact my blood sugar?

  1. During digestion, the starches and sugars in carb-containing foods are broken down. How quickly the body breaks them down (and how many are actually absorbed) depends on the food.
  2. Your body converts most carbs into glucose, a simple sugar. Glucose is absorbed into your bloodstream, where it is shuttled to cells and tissues as a source of energy. Extra glucose is stored in muscles and the liver.
  3. The body closely regulates blood sugar to ensure it has a constant supply of fuel. When blood glucose rises after a meal, the pancreas releases insulin into the blood. Insulin acts as a key, unlocking cells and allowing glucose to enter. When blood sugar is low, another hormone—glucagon—replenishes levels by releasing stored glucose from the liver.
  4. When you have diabetes, either the pancreas produces little or no insulin, or the cells don't respond when insulin comes knocking. If cells are unable to use glucose efficiently, blood sugar stays elevated and the body has trouble accessing its main fuel source.

Wait, so carbs end up as sugar? Isn't that a bad thing?

On the contrary, says Michael Lynch, M.S., RDN, RCEP, CDE, CHWC (PWD type 1) Founder,; wellness coach and registered dietitian, Lifestyle Medicine Program, University of Washington Medicine / Valley Medical Center. "That's our body's fuel. Your body wants to use carbohydrate more than anything else." Your brain runs off of it, and muscles prefer it for energy. Your body uses glucose every time you walk, every time you talk. "It is your metabolic fuel," he says.

Once the carbs from something you eat are broken down into glucose, the body doesn't care what the source was—whether it was an orange or a donut. It's used the same way. But that doesn't mean eating an orange will have the same impact on your blood sugar (or your health) as a donut. Some carbs (like the donut's) enter your bloodstream quickly, spiking blood sugar, while others (like the orange's) take longer to digest, slowing the absorption of glucose.

So why do some carbs take longer to digest?

First things first: a carb isn't a food. In the diabetes world, we often refer to foods that contain carbs as "carbs." But carbs are a macronutrient: they're a part of food.

There are three main types of carbs: sugar, starch, and fiber, and our bodies digest each differently.

  • Sugar: Short carb chains found naturally in vegetables, fruit & dairy
  • Starch: Larger carb chains in grains, legumes & some veggies
  • Fiber: Plant roughage that your body doesn't digest

How a food impacts your blood sugar depends, in part, on which types—and how much of each—are in the food. (Although, as Smithson points out, it depends on other factors, like stress and physical activity, too.)

Take fiber, for example. Even though fiber is a carb, it's not digested by the body. That means that the fiber in, say, a pear or a bowl of oatmeal doesn't get absorbed. "Because fiber isn't broken down, it doesn't raise blood glucose," says Smithson. It also slows the absorption of other carbs.

Is that why I'm always told to eat more fiber?

Actually, fiber has dozens of benefits (see 10 Amazing Health Benefits of Eating More Fiber). It helps lower LDL cholesterol, steady post-meal blood sugar, and keep your gut healthy. Some fibers also keep you feeling fuller longer between meals. A fiber-rich diet can lower the risk of conditions like heart disease, diverticulitis, type 2 diabetes, and, yes, constipation. In fact, a 2013 review found that the risk of heart disease dropped by 9 percent for every 7 grams of dietary fiber eaten per day. Fiber, Smithson says, "is a protective friend and partner—it should be your BFF."

How does fiber work?

Imagine two balls of yarn: one black and one mixed black and red. It would be easy to cut up the first with scissors. But what if to cut the second ball you had to separate the red yarn from the black? How much longer would that take? This is what your body does when it digests carb-containing foods: the black yarn is the digestible carbs; the red yarn is fiber. When you eat foods with fiber your digestive system—the scissors—needs to separate the digestible from the indigestible, slowing everything down. Get your fill of fiber with these 10 Foods with More Fiber Than an Apple.

Do carbs cause diabetes?

The short answer is no. "This is not your fault," says Virginia Valentine, APRN, BC-ADM, CDE, FAADE (PWD type 2), Clinical nurse specialist, Clinica Esperanza, Albuquerque, New Mexico; ADA's 2019 Educator of the Year. Both type 1 and type 2 diabetes are complex disorders, with causes that are not entirely understood. What we do know is that a combination of genes and environment likely play a role.

"The only thing you did wrong is when you selected your grandparents. Maybe next time pick a better set," Valentine adds cheekily. To help her clients understand that there are factors outside of their control that contribute to a diagnosis, she points out many people in their communities eat the very same foods as they do—and many of these people do not have diabetes.

But just because your choices didn't cause your diabetes doesn't mean that your choices don't impact your health. "This is not your fault but it is your responsibility," says Valentine. Rather than dwelling on the cause, try to focus on what you can do now to manage your health.

But why should I eat carbs if my body has trouble processing them?

"A lot of people have started dramatically limiting or getting rid of carbs because they're tired of blood sugar [fluctuations] that they don't know how to manage," says Jennifer Smith, RD, LD, CDE (PWD type 1), Director of lifestyle and nutrition, Integrated Diabetes Services, Wynnewood, Pennsylvania. And since there's so much negative talk around carbs these days, it can seem like cutting back on carbs is a clear win for managing your diabetes.

But completely cutting out carbs is oversimplifying things. "It's very tunnel­visioned," Smithson says. Foods that contain carbs also contain a wealth of other nutrients our bodies need, like vitamins and minerals. And plants provide thousands of unique compounds, called phytonutrients, that help fight disease. It can be hard to think outside the carb-focused diabetes box sometimes, but your body—and your long-term health—depends on these nutrients.

It would seem that a simple solution would be to choose foods that are high in these nutrients, yet low in carbs, but it's not that easy. The most nutrient-

rich foods—"nutrient-dense" is the term our experts use—are plant foods, which all contain carbs. "Vegetables, beans, nuts, and fruits are so high on the nutrient-density chart compared to just about everything else," says Lynch.

Rather than simply thinking about a number of carbs, Lynch suggests thinking about the "quality of carbohydrates" a food provides: how many other nutrients can you get from the carbs you take in?

The bottom line? Your body may have trouble using carbs when you have diabetes, but carb-containing plant foods are still an essential part of maintaining a happy, healthy, and energetic you. The key is not only to keep an eye on the amount you eat, but also to choose wisely in terms of quality.

The ADA supports eating 8–10 servings of fruits and vegetables each day to help lower blood pressure. See our list of fruits ranked by carbs and vegetables ranked by carbs.

OK, I get it: fruits & veggies are good for me. What about grains & legumes?

Grains and beans are also plant foods, so, yes, they contain carbs. But they also contain a lot of other nutrients, including vitamins, minerals, and fiber. The big issue with grains is that they're often refined, which makes them more versatile and easier to use, but also strips them of nutrients. For example, whole wheat is refined into white flour by stripping it of its fiber- and micronutrient-rich bran and hull.

Processed foods are the group of carb foods that aren't as healthy. Refined grains (like white rice) and foods made from processed sugars and grains (like soda, sweets, and white bread) spike your blood sugar quickly. They're also often low in other nutrients. "[Refined grains and sugars are] not what we're talking about when we say 'have carbohydrates,'" says Smithson. "We want to focus on the carbs that have fiber." In short, the more a plant food resembles how it's found in nature, the healthier it is.


So what's the deal with all of these low-carb diets, like keto and Atkins?

The Pros

Many people who try a super-low-carb eating plan like the keto diet or the Atkins diet have initial success losing weight or managing their blood sugars. And that's because these diets involve a lot of healthy choices. Eating healthy fats, getting adequate protein, and cutting out processed carbohydrates, condiments, and fast food—all of these steps are good for you, says Lynch.

But it's not the particular diet that's responsible for these changes. It's the fact that you are creating some rules around what you eat—and following them. "People cut out the high volumes of rice, the granola bars, the sodas or energy drinks, and they've cut out a lot of inflammation from those foods. [They have lower] insulin levels and they feel better," says Lynch.

Cutting out simple sugars and processed foods is a healthy habit that does not need to be keto- or carb-defined at all, says Lynch. "That's generally healthy eating. The problem is that generally healthy eating is just not sexy. It's just the most boring thing ever, so it has to be packaged as something."

The Cons

Turn to any number of blogs, Facebook posts, and forum threads, and you'll hear that extremely low-carb diets help PWDs, in particular those with type 2, keep their blood sugars stable. But on the research side, the evidence is mixed. Most longer-term studies have found that, over a period of 12 months, PWDs who followed generally healthy eating habits had outcomes that were just as good as those who followed a very-low-carb diet (eating, for example, 50 g carbs per day) in terms of weight loss, reducing A1C, and reducing fasting glucose.

Another downside? Extreme diets are very hard to follow for the long term. Later in those same studies, a majority of people in the very-low-carb-diet groups went back to eating the way they had before the studies. "The problem is that most people [try a diet] because they're looking for magic. They're looking for the quick snap of fingers. Then it all turns around again and they're confused and frustrated," says Smith. Lynch agrees: "There are so many emotions and associations that go into the way we eat. When you just let all of that go and follow [someone else's] plan—that's when we have a hard time sticking with it."

Then there are the foods you're avoiding. Beans, legumes, fruits, and whole grains are not foods we need to banish from our diet. "What we know really clearly is that, when we go low-carbohydrate, we are typically low in a lot of pretty important nutrients—potassium, fiber, vitamin C, some of the B vitamins. We cut out a lot of things that the body actually really needs to be healthy," says Lynch. If you replace these foods with more meat, eggs, butter, and cheese, you also add more saturated fat to your diet, which increases your risk of developing heart disease.

"We've become so carb-centric that people have learned, 'Well, if I just reduce the amount of carbs or get rid of them, I don't have to take as much insulin and my blood sugar doesn't have as many big swings,'" says Smith. "But the bad part about that is the reduction of a macronutrient that really is an important nutrient for us."

If you really want to go keto ...

Do your homework

"Make sure you fully understand what following the diet entails," says Smith. Read a book, look online, take a look at the actual meals and foods that you will need to eat, and think about the shopping and meal prep you will need to do. "Some people found that the keto diet, while it gave them good blood sugar, was really a pain in the butt to follow," she says.

Give yourself time

If you do try a new diet, Smith warns that it will take quite a while to get used to it. "It's going to take about a month to feel normal. Many people give up on a habit within two to three weeks, but you have to be patient. You have to give it time. But within the patience you also have to have plans, because this is going to be a change."

Budget accordingly

Eating fewer plant-based foods and more meat and dairy foods is expensive. Can you afford it? Valentine works with many people who are struggling to afford enough food in the first place, so following a lower-carb diet can be a challenge. "A lot of people live on beans and rice and potatoes," she says. When money is a factor, she suggests two strategies: focusing on portion size, and trying to swap in some vegetables where you can (learn more about the keto diet and if it's right for diabetes).

What amount of carbs per day is best for managing diabetes?

We don't have a number for you—there's no one target that's best for everyone. "The guidelines that we have as educators and dietitians basically say to individualize—so it's not one-size-fits-all," says Smithson.

That said, we can give you examples. In research pooled by the Academy of Nutrition and Dietetics, most people with diabetes report eating around 45 percent of their daily calories from carbs, which is about 169 g of carbs a day on a 1,500-calorie diet. Lynch's personal target, and one he suggests as a starting point to his clients, is at least 130 g of carbs per day, which he says is the minimum needed to get enough nutrients and fiber from fruits, vegetables, and whole grains. Valentine has many clients who aim for 100 g or 150 g a day, depending on their diabetes-management and weight-loss goals.

The American Diabetes Association doesn't have enough evidence at this time to recommend one carb target over another, deferring to the nutrition guidelines for the general public, which suggest aiming for 45 to 65 percent of calories from carbs each day to meet the body's needs (learn more about how many carbs you should be aiming for each day).

Of course, just because there isn't a consensus target doesn't mean you can't have your own individual carb goals. All our experts agree that monitoring carb intake—and paying attention to how carb-containing foods influence your blood sugar—is key for diabetes management. After all, even though plant foods like beans, fruits, whole grains, and vegetables are good for you, they still impact your blood sugar, so you'll need to keep an eye on how much of them you eat. Smith recommends making a list of the foods you eat most often, writing down your usual portion size and the number of carbs in that amount. This can help you learn by heart, for example, that 1 cup cooked oatmeal has 30 g carbs.

If that wasn't the concrete answer you were looking for, think about what it does mean: You're free to work with your dietitian and health care team to make a plan that best fits your current habits, needs, traditions, goals, and financial situation. When it comes to the right amount of carbs for you, you are the expert.

So how do I create a meal plan that works for me?

You're likely on the right track. Our experts and the ADA agree that for optimal health and diabetes management, the most important strategy is to find an overall healthful, varied eating pattern "containing nutrient-dense foods." In other words, it's about finding balance and getting the most bang for your carb bucks. (Hello, vegetables!)

A good place to start is to look at the source of your carbs and how they fit into your day, says Smith. "Are they healthy, real food or are they processed, boxed, packaged types of food? Do you have a very carb-laden diet, or do you have a good balance between the carbs, fat, and protein throughout your day?"

The next step is to look at how much food you're eating, especially if weight management is part of your diabetes plan. "For many people with diabetes, the challenge they face balancing carbohydrates and blood sugars comes from eating larger portion sizes, eating less-than-optimal carbohydrate choices, or both," says Lynch.

Valentine agrees. "It's really not as much about what we're eating, it's about how much we're eating." Her own healthy journey started in 2002: through smaller portions and more exercise, she lost 100 pounds over 5½ years. "People thought I totally changed my diet. Not really—I just eat a lot less of the same stuff I always did."

In the end, finding an eating plan that works for you doesn't have to mean totally revamping your diet. "It's important to not abandon your [preferred] way of eating or your favorite meals," says Lynch. Incorporate the foods you enjoy, aim for appropriate portions, and take your finances, time, and emotions into account to create a plan that will make you feel happy and healthy. Because, as all of our experts mentioned when talking about their own management, consistency is key. "This isn't 30 days and just go back to eating whatever," says Smith. "You have to decide on a meal plan that you can stick with." For more direction, check out our Best 7-Day Diabetes Meal Plan and Diabetes Diet Center.

Bottom Line

No matter how you eat, it comes down to feeling good about what you put into your body and how that food makes you feel. And it helps to recognize that, when it comes to diabetes, "there is no perfect," says Smith. "I have many things figured out, but sometimes even those things give me a bad diabetes hair day when all of the planets are not in line."

Though living with diabetes can mean being hyperaware of the amounts and types of carbs you eat, Lynch urges you to truly appreciate the colorful palette that plants add to a plate: "If you look at your meal and you take a moment to see the beauty in what you presented, then there's an opportunity to eat not with fear, but with joy, and to feel energized from that experience."

Are Carbs Evil? | Fall 2019 Diabetic Living