People living with type 1 diabetes, and some people living with other types of diabetes, may count carbohydrate as an effective way of managing your blood sugar levels. It means that your insulin dose can be matched to the amount of carbohydrate you eat and drink.
Being aware of the amount of carbs in food and drinks is important for everyone with diabetes, but carb counting is really helpful if you use basal and bolus insulin.
When you are learning, carb counting can take up a lot of time and effort, but there are lots of resources such as books and apps to help you. Once you’ve got the hang of it, it can lead to better blood sugar management and more flexibility when you eat. It doesn’t mean total freedom but does mean that special occasions and treats can be more easily looked after so you can adjust your insulin to match.
In this guide:
- How do you count carbs?
- Five ways to count carbs
- Three ways to start carb counting
- Top tips for carb counting
- Type 1 and carb counting
- Type 2 and carb counting
How do you count carbs?
Carbohydrates can be counted in two ways, in grams or as carbohydrate portions. One portion is usually equal to 10g of carbohydrate, so find the method that you can understand and that works better for you. Your diabetes healthcare team may teach you a particular method, or you might attend a diabetes education course like DAFNE (dose adjustment for normal eating).
Once you’ve got to grips with estimating the amount of carbohydrate you are going to eat and drink, you'll need to know your insulin-to-carbohydrate ratio.
Insulin-to-carbohydrate ratios are different from person to person, so you will have your own personal ratio depending on factors like your age, weight, activity levels and how sensitive you are to insulin.
Your diabetes healthcare team will help you work this out and, eventually, you might even have a different insulin-to-carb ratio for each meal. They will usually estimate your starting insulin-to-carb ratio and then fine-tune this based on your blood sugar levels.
If you know how many grams of carbohydrate are in a meal and your insulin-to-carb ratio then you can work out the number of units of bolus insulin needed for that meal. So, if your meal had 70g of carbohydrate and your insulin to carbohydrate ratio was 1 unit of bolus insulin for every 10g of carbohydrate, then you’d need to take 7 units of bolus insulin.
Let’s say you have a breakfast consisting of:
- 2 shredded wheat pillows
- 200ml semi-skimmed milk
- 50g Greek yogurt
- 40g blueberries
This would contain approximately 50g of carbs. On a 1:10 ratio, this would be 5 units of bolus insulin.
The amount you actually take will also depend on other factors such as your blood sugar levels, illness or exercise.
Five ways to count carbohydrate
There are five ways you can count carbohydrate in food and drink.
1. Food labels: using the carbohydrate per portion value
If you look at the labelling on the back of a ready-meal, you'll usually see something that looks like this:
| Typical Values | 100g contains | Each oven baked meal (317g) contains |
|---|---|---|
| Energy | 433kJ (103kcal) | 1372kJ (325kcal) |
| Fat | 1.7g | 5.4g |
| Saturates | 0.9g | 2.9g |
| Carbohydrate | 14.1g | 44.7g |
| Of which sugars | 2.0g | 6.3g |
| Fibre | 1.2g | 3.8g |
| Protein | 7.1g | 22.5g |
| Salt | 0.4g | 1.3g |
If you ate all of the ready meal, the amount of carbohydrate you would count is 44.7g. It is important to count the total amount of carbs and not the 'of which sugars' value. When using a per portion value, make sure that this is the actual portion you are planning to eat.
2. Food labels: using the carbohydrate per 100g value
On the back of foods like pasta or rice, you'll see food labelling information like this:
| Typical Values | As sold 100g contains |
|---|---|
| Energy | 1515kJ (360kcal) |
| Fat | 1.0g |
| Saturates | 0.2g |
| Carbohydrate | 77.4g |
| Of which sugars | 0.2g |
| Fibre | 1.8g |
| Protein | 8.5g |
| Salt | <0.01g |
When using the per 100g value, calculate the carbs for the actual amount of the food or drink that you are going to have.
This means if you were planning to cook and eat 80g of rice the amount of carbohydrate you would count is 61.9g not 77.4g. It's important to invest in a good set of scales that are flat based, digital and can be zeroed. It is also important that your scales are accurate to within 5g.
The cooked weight of foods like pasta, rice and potatoes will vary from the raw or pre-cooked weight, so check which values you are using.
3. Reference lists and visual guides
If the food your eating doesn't carry nutritional information, or you're eating out and they don't have the values, carb counting can be more difficult.
Reference lists and visual guides, such as Carbs & Cals, will help you estimate carbohydrate. They list the amount of carbohydrate in handy measures, such as one bread roll, one medium banana or one scoop of ice cream. Some reference lists also contain pictures too so you can compare.
4. Recipe nutrition information
Our recipe pages can take the hard work out of calculating the carbohydrate content.
But there's no need to throw out your favourite recipes and cookbooks. Taking the time to work out the carbohydrate values of your day-to-day meals helps you build up a personal reference list that you can use again and again.
5. Restaurant and cafe nutrition information
Many restaurants and cafes will now list nutritional information for their products online. You may find information that looks like this:
| Per 100 g | Per 114 g serving | |
| Energy | 1381.6 kJ | 575 kJ |
| Energy | 328.1 kcal | 374 kcal |
| Fat | 19.2 g | 21.9 g |
| of which saturates | 6.8 g | 7.8 g |
| Carbohydrate | 22.2 g | 25.3 g |
| of which sugars | 1.4 g | 1.6 g |
| Fibre | 1.3 g | 1.5 g |
| Protein | 15.8 g | 18 g |
| Salt | 3.07 g | 3.5 g |
Many restaurants and snack bars are now providing nutrition information for their menus in a response to us all becoming more health aware.
The nutrition information for this bacon breakfast roll was online and really easy to find. Bear in mind that the values are average values and the dish that you are served may vary in size and content. You still need to use your judgement and experience in restaurants and cafes.
Learn more about eating out with diabetes.
Three ways to start carbohydrate counting
The first step to start carb counting is by finding out more information, such as:
- Do you know which of your food and drink contain carbohydrates? Stop, think and make a mental note of which food and drink will need to be counted.
- Get label savvy – scrutinise the nutrition labels. Pull the food and drink out of your kitchen cupboards and find out just how much information you have to hand.
- Practise estimating the carbohydrate content of your meals – use reference lists to check your accuracy.
Interested and want to know more?
To carbohydrate count successfully you will need a lot more information. You will need to learn all about carbohydrates, learn how to adjust your insulin and be dedicated to monitoring your blood sugar levels frequently.
You will also need the support of professionals either in the form of your diabetes healthcare team or one of the structured diabetes education courses available. You can find out about courses available in your area from your diabetes healthcare team.
Tips for more accurate carb counting
Whether you're new to carb counting or consider yourself well practised, it's always worth refreshing your knowledge and learning extra tips to ensure that your counting remains accurate.
Tips for more accurate carb counting
Reading food labels
While food labels do provide useful information to help you estimate the carb content of the product, remember to look at the carbohydrate of the product, not just the sugars. By counting the total carbohydrate content, all of the ingredients that affect blood glucose levels are taken into account.
Be sure to check if the stated amount is per dried or prepared weight. It’s easy to get caught out as manufacturers sometimes change how they list the nutrient information. For example, some packs of pasta list the carbohydrate content of dried pasta but others as prepared.
Food preparation and portion size
Check that you’re preparing food as suggested as this will make a difference. 100g of very well -cooked pasta (which has absorbed more water) will have a different carb content to 100g of pasta cooked al dente (firm to bite).
Check your portion size - it might be different to that specified. For example, some ready meals state that they ‘serve two’ whereas you might be eating the whole pack in one sitting. Similarly, if you’re cooking for children, you may be serving less than the recommended serving size.
To be sure, it helps to weigh your portion and compare against the suggested serving size as you may be consuming more or less than the stated portion. It’s always useful to check that your food weight remains consistent. For example, is that bowl of cereal the same weight as it was yesterday? If not, you may be eating more, or less, carbs that you’ve calculated.
Some people with diabetes find it useful to use everyday household utensils (e.g. tablespoons) to measure out items such as cereal.
Weighing food and calculating carbs
Fruit, potatoes and other starchy food sizes can vary considerably. The difference in carbohydrate content between a small and large banana can easily be as much as 20g so it helps to weigh and check. With practise, many people with diabetes find that they can visually estimate carb content.
Digital scales and household utensils are readily available. It may sound obvious, but many people find they are more likely to weigh/measure food if the equipment is kept on the kitchen worktop as opposed to tucked at back of cupboard.
The better trained you are to visually estimate carb content, the more precise you’ll be. One strategy people find useful is to put their usual portion on their plate or bowl, before weighing it to check. Often, this reveals that their usual portion is two to three times larger than previously thought.
With many food and drink manufacturers reformulating products (e.g. reducing the sugar content and therefore the reducing carb content), it’s important to always check the food label. Over recent years, many food manufacturers have reduced the sugar content of everyday products such as soft drinks, breakfast cereals, tins of soup, baked beans and even biscuits.
Use technology
Similarly, although the internet is a great way of finding out nutritional information of restaurant and café menus, be aware that recipes are often tweaked and so your information might be outdated. Remember to check back regularly.
Books such as ‘Carb & Cals’ show thousands of photos of food in a range of pre-plated portions on plates with accompanying nutritional information – this means that you can compare your portion alongside to check the carbs. This can be useful when food doesn’t carry a nutrition information label or when you’re eating out and don’t have the nutritional info or scales available. The ‘Carb & Cals’ app – and, indeed, other apps - are also available and allow you to access the info at your fingertips.
To save time and effort, it’s useful to keep a list of the carb content of your usual food and drink to hand. Some people create an online database so they don’t have to constantly check and re-check.
Type 1 diabetes and carb counting
If you live with type 1 diabetes and you are on a basal-bolus insulin regime via injections or an insulin pump, you may have attended an education course or had a one-to-one carb counting session with your healthcare professional.
These courses teach you how to carb count and enable you to effectively match your bolus insulin dose to what you are eating or drinking. This can give you greater flexibility in terms of diet and routine.
For someone taking fixed daily doses of insulin, eating consistent amounts of carbohydrate on a day-to-day basis, and at similar times each day, can greatly help to manage blood glucose levels.
Type 2 diabetes and carb counting
For people with type 2 diabetes, being aware of the carb content of food can help with diabetes management.
Increasingly, people with type 2 diabetes who use insulin are being taught about carb counting, both on courses or in consultation with their health care professional.
There are many carb counting courses available so do ask your healthcare team what’s available. Even if you’ve been on a carb counting course already, many areas run refresher sessions, and we do know of people who have attended a second course if their initial one was a while ago. You can find out about courses available in your area from your diabetes healthcare team.
Continue learning
In these videos, Jess, who has been carb counting since she was diagnosed with type 1 diabetes at the age of 14, will take us back through the basics and help you to identify carbohydrates in different types of food, and learn how carb counting can help you to manage your blood glucose levels.
How to identify carbohydrates
Carbs are found in starchy foods like bread and pasta, in naturally occurring sugars in fruits and dairy products as well as free sugars, found in sweets, chocolate, sugary drinks, cakes, biscuits, honey and syrups. Most carbs break down into glucose once digested. The total carbohydrate content of meals, snacks and drinks has the greatest impact on blood glucose levels after eating.
Carbs can be further broken down into fast-acting, medium-acting and slow-acting.
- Fast-acting carbs: Glucose tablets, glucose drinks, full-sugar soft drinks or squashes, jellies (not diet), sweets.
- Medium-acting carbs: Bread, pasta, potatoes, yams, breakfast cereal, couscous.
- Slow-acting carbs: Pearl barley, peas, beans, lentils, sweetcorn, pumpkin.
Slow-acting carbs are absorbed very slowly. They may not need to be matched with insulin unless eaten in large quantities. The saying 'everyone is unique' applies to carbs too, so monitor your blood sugar levels to see how different foods affect you – and, of course, speak to your team for help.
Plenty of foods don’t have any carbs in them at all. Such as:
- Protein: Meat, fish, seafood, eggs.
- Fat: Lard, ghee, margarine, oils.
- Dairy: Cheeses, butter.
- Vegetables: Asparagus, broccoli, bell peppers, spinach, mushrooms, avocado.
- Drinks: Water, sugar-free drinks, diet drinks, diet squashes, black tea and coffee.
Reading food labels
This video will help you to understand food labels and learn about the carbohydrate levels in everyday meals, with tips and advice from Jess along the way.
No labels? No worries
When you’re out and about, it can be harder to get information about the food you want to eat. But that shouldn’t get in the way of having a great time.
This video will help you understand which carbohydrate foods are more likely to have a big effect on your blood glucose levels and hints for what to do when no carbohydrate information is available.
How carbs interact with your body
Understanding how different carbs interact with the body is key to carb counting. Jess explains the two main ways of counting carbs, and how to work with your healthcare team to match the amount of insulin you need to take.
Find out more
- Support forum: Connect with other people living with diabetes and tap into their knowledge and experience.
- Online communities: There are loads of online diabetes communities out there that can be a great source of information and support.
- Local groups: Find a friendly and welcoming local support group near you.
- BERTIE – Online type 1 education programme: Learning modules and information that cover a wide range of topics for people living with type 1.
- Try a different carb: Fed up with the same old thing day in, day out? It’s time to experiment and introduce some new tastes and flavours into your diet.
- Carbs & Cals book: Covers healthy eating, nutrients in food and carbohydrate and calorie counting. There’s also a Pocket Counter version.
- DAFNE – type 1 education course: Dose Adjustment for Normal Eating – type 1 diabetes education programme delivered by the NHS to give you the skills you need to estimate carbohydrate in each meal and to give yourself the right does of insulin.
- CHOICE – Type 1 education in NI: Education course in NI for young people with type 1 (up to age 19).
