Calculating carbohydrate content

The first step is to familiarise yourself with foods that do contain carbs and those that don’t. Some foods have none (e.g. meat and fish), some have a small amount (e.g. most vegetables), and others have high amounts of carbs (e.g. bread, pasta, rice and potatoes).

Have a look at the plates below to identify the carbohydrates in the following meals:

The fish doesn’t contain any carbohydrate and the salad vegetables will have minimal amounts of carbohydrate. As the salad vegetables have very little carbohydrate content, you will not need to count the carbs in them.

At first glance, this meal looks like it contains very little carbohydrate as it is mainly protein. However, 250g of sweet and sour pork has around 30 grams of carbohydrate. The marinade for dishes like this usually contains sugar and starch, such as cornflour, which contributes to the total carbohydrate content.

Common foods forgotten about

There are some carbohydrate-containing foods that are often overlooked when you are first starting to carb count. Pulses such as beans, lentils and peas often fall into this category.

Pulses are high in fibre and protein and they release their energy slowly, so they don’t cause a big spike in blood glucose levels, especially if the portions aren’t too big. For this reason, you may have been advised not to count the carbohydrate in pulses. However, if they are eaten in larger quantities then you may find you need to match them with insulin.

Every person is different and regular blood glucose monitoring after meals will let you know what impact they have on your blood glucose levels. It is important to check with your diabetes team for specific advice on how to count the carbs in pulses as there is no one-size-fits-all approach to this.

Don’t forget the drinks!

Drinks such as cocktails/ punches can have added sugar through fruit juice or syrups. We’ll cover alcohol in more detail later in the course but it’s important to be aware of what added sugar there may be in your drink.

Hot drinks from coffee shops such as lattes and cappuccinos can also have a significant carbohydrate content from the sugar in milk and any added syrups.

Calculating carb content of meals

To calculate the amount of carbohydrate of a meal, you need to:

• Identify the foods that contain carbohydrate
• Work out how much carbohydrate you are eating
• Know the weight of each carb by weighing or referring to pictures or food labels for carbohydrate values
• Add these values together to get the total carbohydrate content of the meal    

Over the next couple of topics, we will explain how you can calculate how much carbohydrate you are eating by using food labels, reference lists and handy measures. You will then use this information to work out how much bolus insulin you need to take.