All About Carbohydrates

Without a doubt, confusion about carbs is often in the minds of people with diabetes (and their loved ones). With this primer we aim to clear up that confusion and encourage you to put foods that contain healthy sources of carbohydrate back on your plate.  

Carbohydrate Basics

When we eat food, we typically eat several foods at the same time and call these meals or snacks. Foods (and some beverages) contain calories. Calories are contributed by three macronutrients (big) - carbohydrate, protein and fat.1 (Alcohol also contributes calories.) Before discussing carbohydrates specifically, let’s look at the big picture. This includes understanding how foods are “packaged” and the relationship between carbohydrate, protein and fat.

Carbohydrates are the body’s primary and preferred source of energy. They’re easy for the body to break down and get to your cells to function. 

Confusingly, some people use the word “carbs” to describe foods like pasta, potatoes, grains, and legumes. More accurately, carbohydrate is one of the three macronutrients that the foods just mentioned contain. But these foods don’t just contain carbohydrates. They also contain another macronutrient - protein. (That’s without adding any ingredients, toppings or seasonings when you prepare them.)  Another example to consider is milk. Milk contains mainly carbohydrate, some protein (more than pasta and potatoes) and, depending on the type of milk, some or no fat. 

Keep in mind we don’t eat carbohydrate, protein and/or fat separately. We eat foods and drink beverages that contain more or less of these three macronutrients. Again, foods and beverages are packages of more or less carbohydrate, protein and fat.² Got the picture? 

Three Types of Carbohydrates

Going one step deeper, there are three types of carbohydrate in foods – starches, sugars and dietary fibers. Some foods contain one type and others all three. 

Foods that contain carbohydrate range from healthy to, well, not-so-healthy - from lettuce, lentils and lemons, to cake, cookies and candy (see lists below). A major plus to eating healthier sources of carbohydrate is to provide the body with sufficient amounts of dietary fibers that are only found in carbohydrate-containing foods. These foods also contain an array of the vitamins and minerals you need for good health.³

Healthier Sources of Carbohydrate* 

• starches, such as breads, cereals, pasta
• starchy vegetables, such as corn, squash, and sweet and white potatoes
• legumes (beans and peas) (most of their calories is from carbohydrate, but they do contain more protein per serving than other starches)
• vegetables (non-starchy), such as lettuce, broccoli, carrots, and beets 
• fruits, such as apples, oranges, fruit juices, and raisins
• dairy foods, such as milk and yogurt (note: cheese contains a small amount of carbohydrate and mainly protein and fat)

*Whether a food remains healthy when you eat it depends on what you add or put on it (if anything) when you prepare to eat it. 

Not-so-Healthy Sources of Carbohydrate

• Sugary foods, such as regularly sweetened soda, gumdrops, hard candies and maple syrup (these contain nearly 100% carbohydrate)
• Sweets, such as desserts, ice cream, cookies, and chocolate bars (these foods contain varying amount of carbohydrate [sugars and/or starches] and fat)

Carbohydrates, Diabetes and How Much to Eat

The amount of carbohydrate people eat varies around the globe. It’s generally based on peoples’ access to and availability of an array of foods. People with diabetes, on average, eat a similar amount of carbohydrate, protein and fat, as the general public – about 45% of carbohydrate, 16-18% protein and 36-40% as fat.⁴ 

For points of reference, the Dietary Guidelines for Americans recommends people eat anywhere from 45 – 65% of their calories from carbohydrate.⁴ The World Health Organization (WHO) doesn’t recommend a specific amount of carbohydrate to eat, it does give specifics on which carbohydrate –containing foods to eat more or less of to stay healthy.⁵  Lastly the American Diabetes Association, in their most recent nutrition guidance, offers four guideposts with which to choose high-quality sources of carbohydrate and limit those with low nutritional value.⁴ These guideposts reflect WHO’s healthy diet guidance. 

• Emphasize eating non-starchy vegetables  
• Choose whole foods over highly processed foods 
• Minimize foods and beverages that contain added sugars and refined grains
• Replace sugar-sweetened beverages with water as often as possible⁵

Though plenty of foods that contain carbohydrates are healthy, they get the evil eye from some people with diabetes. That’s understandable because people focus on the fact that carbohydrate is the macronutrient in foods that most raises blood glucose levels.  However, for many reasons this does not translate to a recommendation to avoid or significantly limit foods with carbohydrate.³ 

What does have the greatest impact on the glucose levels of a person with diabetes is the amount of available insulin that is at the ready when it’s needed to process carbohydrates, protein and fat. (Protein and fat can have an impact on glucose levels.) (It’s not only the amount of carbohydrate one eats.) If the body has sufficient insulin around (either from the insulin dose taken or produced by the body) when you eat carbohydrates the body can keep glucose levels within desired targets. Therefore, a big goal of glucose control is having adequate insulin at the ready when it’s needed.⁶

Research has not revealed an ideal amount of carbohydrate (nor protein and fat!) for people with diabetes to eat, either type 1 or 2 or taking insulin or using other glucose-lowering medication. However, research does show that reducing overall carbohydrate consumption to around 40% of calories or less, may help manage glucose levels.⁷ For a frame of reference 40% of calories as carbohydrate eating 1500 calories per day is: 150 grams. At 2000 calories per day it is: 200 grams.  

Keep two important caveats in mind with regard to how much carbohydrate to eat. One, it’s important to partner with your healthcare providers to zero in on an eating pattern - a combination of foods or food groups - that fits to you and your needs, and is maintainable over many years to stay healthy. Two, pay way more attention to the quality of the carbohydrate containing foods you eat rather than the total amount. These ADA eating guideposts are a great reference tool.⁸

In summary, when it comes to the amount of carbohydrate to eat, you don’t need to severely restrict or eliminate carbohydrates to manage your glucose levels over time. Focus on choosing quality sources of carbohydrate and eat reasonable amounts of these foods. Fit sugary foods and sweets in on occasion and in limited quantities. They do raise glucose levels and don’t offer much in the way of nutrition, but they are enjoyable. 

If you have type 2 diabetes and can’t, through healthy eating, hit the glucose and A1C targets that you and your healthcare providers set then you may need to take one or more glucose lowering medications. This doesn’t mean you’re bad or a failure (you can blame your pancreas!). It simply means that your type 2 diabetes has progressed. Checking your glucose levels regularly helps paint the picture of their ups and downs for you and your healthcare providers. These results guide how to manage your diabetes. Trust that the picture will continue to change over time. That’s why self-monitoring of glucose levels is a critical aspect of diabetes self-care.   

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All of the information in this article is based on the following sources:

1. Avita Health System, 2020. Macronutrients: A Simple Guide to Macros. [webpage] Available at: https://avitahealth.org/health-library/macronutrients-a-simple-guide-to-macros/ [Accessed 19/01/21].

2. Warshaw, H.W., 2016. Diabetes Meal Planning Made Easy. 5th ed. Virginia: American Diabetes Association.

3. Healthline, 2020.Carbohydrates: Whole vs. Refined- Here’s the Difference. [webpage] Available at: https://www.healthline.com/nutrition/good-carbs-bad-carbs [Accessed 20/01/21].

4. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015. Dietary Guidelines for Americans. 8th ed. Washington: Department of Agriculture. 

5. World Health Organization. 2020. Healthy diet. [webpage] Available at: https://www.who.int/news-room/fact-sheets/detail/healthy-diet [Accessed December 20/01/2020].

6.Diabetes.co.uk, 2019. Insulin. [webpage] Available at: https://www.diabetes.co.uk/body/insulin.html [Accessed 20/01/21].

7. Gray, A., Threlkeld, R.J., 2019.Nutritional Recommendations for Individuals with Diabetes. Endotext, [online]. Available at: https://www.ncbi.nlm.nih.gov/books/NBK279012/ 

8. American Diabetes Association. 2020. 5. Facilitating behavior change and well-being to improve health outcomes. Diabetes Care. [online]. Available at: https://pubmed.ncbi.nlm.nih.gov/31862748/.