Carb Counting Series: The Different Methods of Carb Counting

Carbohydrate counting can be a mentally challenging task, whether mathematics is your strong suite or not. In fact, studies have reported that even members of your diabetes healthcare team can struggle with it!¹ Face it - when you’re hungry and just want to get some food in your belly, calculating carbohydrates is not typically your foremost thought. However, as accurate carb counting can positively impact your HbA1c and quality of life,² it could be something worth mastering. Here we discuss the different ways to approach carb counting.

Advanced Carb Counting

Don’t be put off by the name – advanced carb counting is also known as consistent carb counting. It tends to be adopted by people living with type 1 diabetes as it involves using your insulin-to-carbohydrate ratio.³

Consistent carb counting involves understanding the amount of carbs you’re consuming. This information can be calculated either using grams or as portions (more on this later!).⁴ Once you’ve counted the amount of carbs in your meal, you can then calculate how many units of insulin you need to cover their effects.^3,4

Consistent carb counting has the advantage of allowing some degree of flexibility with your meals. This is because your insulin dosage is adaptable in response to what you’re about to eat.⁴ For example, your morning insulin-to-carbohydrate ratio is 1:20. One day for breakfast, you count 40g of carbs – this means you’ll need to take 2 units of insulin. The next day, your breakfast is only 20g of carbs. For this meal, you only need 1 unit of insulin.

Basic Carb Counting

Basic carb counting, also known as carb awareness, is the alternative to advanced/consistent carb counting. It’s more likely to be used by people living with non-insulin dependent type 2 diabetes.³

This method of carb counting involves aiming for a pre-determined, set amount of carbs every day. Your diabetes healthcare team will help establish your ideal daily carb intake based on your medication, weight targets, and overall diabetes management.³ For example, your dietitian may recommend you aim for no more than 50g of carbs per meal.

Carbohydrates In Grams

There are two ways to calculate the number of carbs you’re about to consume. One way is in grams.⁴ This can be the easiest method for some people (though not all), as many food and drink nutrition labels will state the amount of carbs in grams. Remember that the values on nutrition labels are specified per amount of food/drink. For example, you may see that 100g of pasta contains 35g of carbs. Alternatively, you may see written that 1 serving contains 40g of carbs.

Carbohydrates In Portions or Exchanges

This method measures carbohydrates in portions, exchanges, or equivalents.^2,4 One portion or exchange is typically equal to 10g of carbohydrate,⁴ but could also correspondent to a different amount such as 15g.²

You will still be able to use nutrition labels to work out the number of grams and therefore portions/exchanges of carbs in your meal. It may take a little more maths at the start but can make it easier for your insulin dosing. For example, one portion equals 10g of carbs and your insulin-to-carb ratio is 1:10, or one unit per portion. Your snack has 20g of carbs (two portions), which neatly works out to 2 units of insulin.

Final Thoughts

Your diabetes healthcare team can help you to find out which method works best for you, as well as helping your sort out of your insulin-to-carb ratio. In the meantime, be patient with yourself – learning to carb count can be challenging!

References

1. Deeb A, Al Hajeri A, Alhmoudi I, Nagelkerke N. Accurate Carbohydrate Counting Is an Important Determinant of Postprandial Glycemia in Children and Adolescents With Type 1 Diabetes on Insulin Pump Therapy. Journal of Diabetes Science and Technology. 2017;11(4):753-758.
2. Vaz E, Pofirio G, Nunes H, Nunes-Nogueira, V. Effectiveness and safety of carbohydrate counting in the management of adult patients with type 1 diabetes mellitus: a systematic review and meta-analysis. Arch Endocrinol Metab.2018;62(3):337-345.
3. Diabetes.co.uk. What is Carb Counting and How to Count Carbs. https://www.diabetes.co.uk/. 2022. Available at: https://www.diabetes.co.uk/diet/carbohydrate-counting.html. (Accessed July 2022).
4. Diabetes UK. Learn About Carb Counting. https://www.diabetes.org.uk/. 2021. Available at: https://www.diabetes.org.uk/guide-to-diabetes/enjoy-food/carbohydrates-and-diabetes/nuts-and-bolts-of-carb-counting/learn-about-carb-counting. (Accessed July 2022).