The major advantage of carb counting is that it gives flexibility to eat a meal or snack when ever you wish and gives a freedom to choose any food you like.

The carbohydrate content of a meal is quantitatively a determining factor of the mealtime insulin doses. For people with Type 1 Diabetes, blood glucose control is best achieved by matching rapid acting insulin dose directly to the amount of carbohydrate consumed; this method is called Carbohydrate Counting. The calculations are based on the ratio of insulin to carbohydrate content. For example, 1 unit of rapid acting insulin may be appropriate for every 10g of carbohydrate in a meal. This ratio is individualized from patient to patient, and it may even vary for the same patient at different times of the day. For example, breakfast ratio might be 1u:5g, lunch 1u:10g, dinner 1u:8g. Patients will also have to take into account pre-meal blood glucose level and give a correction dose if blood glucose is above the target range. The correction factor is again individualized to each patient and it may vary at different times of the day. For example, the most often used correction is 1u:3mmol/l (e.g. 1u of rapid acting insulin will reduce your blood glucose by 3mmol/l).

Carbohydrate counting method requires you to learn following:

  1. About foods that contain carbohydrates.
  2. Estimate the grams of carbohydrates in the portion of food you eat.
  3. Learn about carbohydrates with different rate of digestion (e.g. Glycaemic Index)
  4. Find your individual insulin to carbohydrate ratio.
  5. Find your individual “correction factor” – extra units of insulin to correct a high blood glucose level that is above your personal targets.

Initially carbohydrate counting and insulin dose calculation may sound like a difficult task. However, you will gradually become more familiar with the process and it will eventually become second nature.

The good news is that the technology for the management of type 1 diabetes is moving fast and is making living with type 1 diabetes a lot easier. If you are using insulin pump therapy, you are probably already using the bolus calculators built into most pumps. If you are on  MDI therapy there are now several blood glucose meters available with a built in mealtime (bolus) insulin calculator for calculating suggested insulin doses which means that it eliminates the need for you to make any mathematical calculations when estimating your mealtime insulin dose. Once you have worked out and programmed the information into the meter along with your insulin-to-carbohydrate ratio and correction factors, the rest is then calculated by the meter. Of course, you will still need to estimate the number of carbohydrate grams in your meal.

In addition, Carbohydrate Counting would not be complete without learning following:

1. Your background insulin adequacy

2. Hyper and hypo treatment

3. Sick day rules

4. Alcohol and blood glucose

5. Exercise and blood glucose

Special note for insulin pump users

Insulin pump therapy has revolutionized diabetes care. The randomized and non-randomized studies have shown the efficiency of Insulin Pump Therapy across all age groups. However, to make most of the technology, you also need to know about carbohydrates, how to monitor your blood glucose regularly, how to re-address insulin to carb ratios and about correction factors, how to re-address the adequacy of your background basal rate and use correct strategies for high and low blood glucose. Using fasting tests help you learn about your individual background insulin requirements over 24-hour period and allow programming of your pump to your individual needs. It is also important to make full use of the extra features available on your pump, such as temporary basal rates and multi wave and square wave boluses.

Example of the sensor download of the 7-day blood glucose profile, for the patient, before and after insulin pump therapy

Before insulin pump therapy

3 months after starting pump therapy

Useful links for more information on type 1 Diabetes and carbohydrate counting:



At ACE diets we can help you to learn the differences between carbohydrate counting and general diabetes control. We are experts in advising people with multiple daily injection therapy (MDI) as well as those on insulin pump therapy (CSII). Together we can re-address the adequacy of your background (basal) insulin. We will re-inforce the rules for hyper and hypo treatment and try to find a right balance for the strategies during exercise and illness.*

To give you the best advice, we will use:

  • Your blood glucose meter and/or insulin pump downloads
  • Your carbohydrate and glucose monitoring diaries (to establish Insulin: carb ratios, correction fastors)
  • Your fasting blood glucose monitoring diaries (to establish the adequacy of your background insulin)
  • You don’t have to live locally to reach our clinic, as we can arrange on-going support by using Skype, e-mail or phone

* ACE diets is not a replacement of the care you are currently receiving from your Doctor and your Diabetes Care Team, but a complimentary private service to enhance your existing knowledge of the condition and its management.