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Nutrition

Type 1 Diabetes and Carbohydrate (carb) counting for adults and children

Patient Information Leaflet

 

Type 1 diabetes

Type 1 diabetes is an autoimmune condition in which the pancreas stops producing insulin, meaning people must replace their own insulin to process dietary carbohydrates and maintain safe blood glucose levels. Carbohydrate counting, a method of accurately counting the grams of carbohydrate in meals and matching them with the correct insulin dose, is essential to prevent both high and low blood glucose levels. This leaflet is intended for adults and children with Type 1 diabetes, regardless of whether they use insulin pumps or multiple daily injections.

 

Healthy eating with Type 1 diabetes

There is no special diet for individuals with Type 1 Diabetes. Instead, a healthy balanced diet suitable for the rest of the population is advised. There is no need for diabetic foods. Also, there is no need to avoid sugar, but it is advised to opt for sugar-free drinks (water, diet/”zero” drinks, diet squashes, black tea and coffee) and to use sweetener instead of sugar on food and drinks unless treating hypoglycaemia (glucose less than 4mmol/L). Carbohydrate (carb) counting is the best way to ensure your blood glucose levels are maintained in the target range. It also allows flexibility with your food choices which can be matched with correct doses of mealtime/bolus insulin.

 

Steps to Carb counting

 

Step 1 – Identify carb foods in your meal to “count”

What to “count”

All carb foods are broken down into glucose which is released into the blood.

The amount of carb eaten is the most important factor when considering the impact of food or drink on your blood glucose levels.

It is advised to “count” the foods in the below table:

CARBOHYDRATES 
Starchy Foods Foods containing sugar
Simple sugars Natural sugars
Bread/cobs/rolls
Rice
Crackers
Potatoes (chips & crisps)
Pasta
Breakfast cereals
Anything made with flour
Chapatti/Naan/Roti
Couscous
Pastry (pies, sausage rolls)
Yam
Fufu
Plantain
Eba/Gari
Coating – breaded/batter
Baked beans
Parsnips
Peas
Sweetcorn		 Sugar
Jam
Fizzy drinks
Sweets
Cakes
Biscuits
Desserts
Chocolate
Jar sauces
Sauces (ketchup/brown/BBQ)
Tinned spaghetti
Fruit juice and smoothies
Honey
Maple Syrup
Baked beans		 Milk
Yoghurt
All fruit

 

It is advised to count the milk in meals e.g. cereal, but milk in hot drinks between meals does not need to be counted.

Some people find that by counting all the carbs in more slowly released carbs e.g. baked beans, peas, sweetcorn, can cause hypos so if this is the case we would advise counting half the carbs in these foods.

Protein and fat can be converted to glucose in the body but not as quickly as with  carbs. We, therefore, do not routinely advise counting protein and fat, but if you feel these foods are having an effect on glucose levels you can speak to your Dietitian for advice.

 

What to not count

You do not need to count any food which is just protein or fat. There is no need to count meat, fish, seafood, eggs, cheese, lard, ghee, butter, margarine or oils. However, if these foods have a breaded or battered coating (e.g., fish fingers, chicken nuggets, breaded cheese bites) you would need to “count” the carbs in them.

You will notice that some vegetables are in the table above under starchy carbohydrates and need to be counted. All other vegetables and salad items do not need to be counted as they generally have very low amounts of carbs.

 

Step 2  – Work out the amount of carbs in grams (g) in your portion

It is useful to purchase a set of digital weighing scales (flat-based and can be zeroed) when starting out and make a note in a book or on your fridge of the grams of carbohydrates in your typical meals. Once you are familiar with your typical portion size you can use household measures e.g., cups, plates, spoons and bowls to measure the portion out day-to-day without having to weigh every time.

If the packaging is available, it is always best to look at the carbohydrate values on this as it is specifically for that product. Make sure you look at total “Carbohydrate” (circled below) and not just “of which sugars” or “of which starch”. “Carbohydrate” includes “of which sugars” in its total.  “Carbohydrate” is always found on the back of packaging. It is useful to find the carbohydrate per 100g value to use for the calculations.

 

To calculate the carbohydrate (g) in your portion:

Using the amount of carbohydrate (g) per 100g, divide this number by 100 (as the product weighs 100g). Then next multiply this answer by the weight of your portion (g).

Carbs per 100g (g)                 x               Weight of your serving (g)

————————-
Divided by 100

 

Example

Bran flakes Per 100g
Energy 359kcal
Protein 12g
Carbohydrate 65g
of which sugars 14g
Fat 2.6g

 

If you measured your bran flakes portion as 45g.

65 / 100 = 0.65

0.65 X 45g = 29.25g (round to nearest 1g)

So 29g carb in your 45g serving of bran flakes.

 

If you have milk on your bran flakes you need to “count” that also.

Semi-skimmed milk Per 100ml
Energy 50kcal
Protein 3.6g
Carbohydrate 4.8g
of which sugars 4.8g
Fat 1.8g

 

If you measure out that you have 150ml milk….

4.8 / 100 = 0.048

0.048 x 150 = 7.2g carbs (round to nearest 1g)

= 7g carbs

Bran flakes carbs added to milk carbs = 29 + 7 = 36g carbs

 

Cooked vs. dried

Cooked and dried varieties of certain foods will weigh differently due to absorbing or losing water during cooking. Therefore, it is important to make sure you are looking at the correct value depending on if your food is cooked or uncooked.

It is advised to weigh pasta and rice cooked (highlighted in bold below). The carbs per 100g for cooked and uncooked pasta and rice are shown in the table below.

Carbohydrate food Carbs (g) per 100g
White rice (cooked)      30
White rice (uncooked) 86
Brown rice (cooked) 32
Basmati rice (cooked) 30
White pasta (cooked) 22
White pasta (uncooked) 74
Wholemeal pasta (cooked) 23

 

Example

You weigh your cooked portion of wholemeal pasta on your plate at 165g.

23/ 100 = 0.23

0.23 x 165 = 39.95 (round to nearest 1g)

40g of carbs in your serving

 

Eating out/takeaways

When having takeaways or eating out, packaging is usually not available, and your “best guess” may have to be made. Avoid giving your mealtime insulin before the meal arrives on these occasions in case for some reason it is delayed and your insulin works before it comes, putting you at risk of hypoglycaemia. You will also be able to estimate the carb content better if you can see the portion of the food. These resources can help when eating out or having a takeaway.

 

Step 3 – Decide how many units of mealtime/bolus insulin to give

To decide how many units of your mealtime/bolus insulin (for example, Apidra, Fiasp, Humalog, NovoRapid) to give, you need to consider your insulin:carb ratio (ICR) and whether you need a correction dose added to this. Insulin works best when given before you eat your meal. Your diabetes team will advise you of the length of time before a meal that is best for your insulin type and meal type.

 

Insulin: carb ratio (ICR)

Your ratio advises how many grams of carbohydrate 1 unit of your mealtime insulin will cover.

For example, 1:10 suggests that 1 unit of mealtime/bolus insulin will cover 10g of carbohydrate. The number on the right-hand side of your ratio is your “special number”. To work out how many units of mealtime insulin to give, divide your total carbs in your meal by this special number. For example, if my meal total is 80g of carbohydrate: 80 divided by 10 = 8 units.

 

Insulin sensitivity factor (ISF)

Your Insulin sensitivity factor (ISF), otherwise known as correction or adjustment dose, describes describe how much 1 unit of your mealtime insulin reduces your blood glucose levels by. For example, an ISF of 1:3 or 1 unit reduces by 3mmol/L means that 1 unit of your mealtime insulin reduces your blood glucose level by 3mmol/L.

It is used to bring a higher than target glucose level down into range and is only needed if glucose is above range. At a mealtime if a correction dose is needed, this needs to be added to the mealtime/bolus insulin dose to cover the carbohydrates. Do not correct at intervals of less than two hours. Correction charts can be provided which can make this process more straightforward.

Example

Your insulin: carb ratio is 1:10, your ISF is 1:3. You are eating 50g of carbs and your glucose before the meal is 12mmol/L.

50/10 = 5 units to cover your carbs

1 extra unit would bring your glucose level down from 12mmol/L to 9mmol/L. A 2nd extra unit would bring your glucose level down from 9mmol/L to 6mmol/L so 2 extra units needed to bring you into range.

5 + 2 = 7 units for this meal

 

Recipes

For recipes, use the methods described above to find the amount of carbs in each ingredient that needs to be “counted”. Add these values for each ingredient up to get the total amount of carbohydrate in the whole recipe.

Work out how many portions your recipe makes and divide the total carbohydrates by this number. This will give you the amount of carbohydrate in each portion.

An example is shown below for apple pie.

Ingredients containing carbs Weight (g ) Carbs per 100g Total carbs. in ingredient, using formula Calculations, using formula
Apples 1000g (1kg) 12g 120g 12÷100 = 0.12

0.12 x 1000 = 120g

Caster sugar 130g + 50g 100g 180g 100÷100 = 1

1 x 180 = 180g

Sultanas 40g 70g 28g 70÷100 = 0.7

0.7 x 40 = 28g

Flour 300g 76g 228g 76÷100 = 0.76

0.76 x 300 = 228g

Total carbs. in recipe (makes 8 portions)

 

 556g

 

 

 
Carbs. per portion 1/8 69.5g

 

Physical activity

In general terms, physical activity reduces your blood glucose levels both during and for up to 12 hours after the activity, increasing your risk of low blood glucose levels in this time. However, some types of physical activity (those of higher intensity and/or induce adrenaline) can instead increase blood glucose levels. It is very important to test your blood glucose levels as everyone has a different response to exercise.

For planned activity, it is possible to reduce your mealtime insulin at the meal before if the activity is planned to take place in the next two hours. If the activity is unplanned, you may need an extra fast-acting carb snack before. Fast-acting glucose is what is used to treat your hypos and includes: glucojuice, glucose and dextrose tablets, lucozade and lucozade sport to name a few. You should aim to have a blood glucose level of around 7-8mmol/l immediately before and ideally during exercise. If your blood glucose is below this then a snack will be required. If your blood glucose is already 7-8mmol/l then a snack may not be needed but this depends on the intensity and duration of the exercise. Carbohydrates to prevent hypos are in addition to those needed to fuel the exercise.

You should never exercise if your blood glucose level is above 13.9mmol/L and you have blood ketones of 0.6mmol/L or above.

 

Snacks

If you are on an insulin pump, you need to bolus for every snack containing carbs. However, if on injections, it is best to avoid snacks with10g of carbs or more. This is because any carbohydrate taken without mealtime/bolus insulin will cause your glucose levels to rise. If you do have a snack containing 10g or more carbs, it is necessary that you take an extra injection of bolus/mealtime insulin.

Examples of snacks of less than 10g carbs are included on the below table.

 

INSERT TABLE

 

Pre-bed snack

If you are not on an insulin pump, it is advised pre-bed to aim for a blood glucose level of 7-8mmol/L. Therefore, if blood glucose is below this pre-bed you are advised to have a 10-15g carbohydrate snack.

 

Avoiding glucose spikes

Your Dietitian will be able to discuss your personal carbohydrate requirements with you.

Carbs can be classified as fast-acting, medium-acting or slow-acting.  Fast-acting carbs are useful for situations where glucose levels need to rise quickly e.g. hypoglycaemia and for physical activity. These include glucose tablets, glucose drinks, full-sugar soft drinks sweets. Medium-acting carbs include bread, pasta, potatoes, yams, breakfast cereals and couscous.

Slow-acting carbs are the best choices at mealtimes to help smooth out post-meal glucose levels. These include whole grains, pulses (chickpeas, lentils, beans, peas), nuts, and vegetables and fruits with their skins. In addition, it can be very helpful to add protein, fibre and healthy fats to carbs eaten to reduce the post-meal spike. For example, adding cheese or peanut butter or baked beans or eggs to toast can cause less of a spike than when eating toast alone. Another example would be adding full-fat Greek yogurt or seeds/nuts/nut butter to cereal/yogurt/fruit. It is also worth noting that insulin can make you feel hungrier and gain a small amount of weight, therefore choosing foods which fill you up e.g. protein and fibre can be useful.

 

Reducing “free sugars”

The government recommends that “free sugars” defined as “sugars added to food or drinks, and sugars found naturally in honey, syrups, and unsweetened fruit and vegetable juices, smoothies and purées” should not make up more than 5% of the energy you get from food and drink each day. The below are the recommendations for different ages per day:

Adults – no more than 30g

Children 7-10 years – no more than 24g

Children 4-6 years – no more than 19g

Children 2-3 years – no more than 14g

Children aged 1 – no more than 10g

Babies under 1 – sugars should not be added to food/drinks

 

Hypoglycaemia treatment (glucose levels less than 4mmol/L)

Your nursing team will discuss hypoglycaemia (hypos) in more detail but as a general rule for mild hypos, it is advised to have 0.3g of fast-acting glucose per kg of body weight up to a maximum of 18g glucose treatment. Pure glucose is best in this instance e.g. glucojuice, glucose tablets, dextrose tablets, lucozade original or lucozade sport. For example, a 30kg child will require 10g fast-acting glucose and a 60kg child or adult will require 18g fast-acting glucose.

 

Food refusal and illness

If you do not finish a carbohydrate component of a meal that you have given insulin for, it is advised to top-up with the same amount of carbs not eaten from a different carb food source. With children is it advisable to avoid topping up with sweet/desirable foods in this instance as they may learn that if they do not eat a meal they get a “treat”.

Avoid pressure and distractions at mealtimes, ideally eat altogether as a family at a table, and give children approximately thirty minutes to finish a meal. If you are unwell it is important to continue to eat carbohydrates and give insulin. Therefore, in this situation you may need easier to tolerate foods such as sugary fizzy drinks, Lucozade, sweets, or ice cream which can be carb counted and matched with mealtime insulin. In these situations, it can be advisable to give the mealtime insulin after if amount tolerated is not clear.

 

Alcohol

Alcohol can impair your liver’s ability to release stored glucose, increasing the risk of hypoglycaemia, especially if you drink on an empty stomach. Glucagon injections will not work as well. Therefore, your target glucose when out drinking alcohol should be higher at 7-10mmol/L and you should monitor your blood glucose more frequently. Alcohol recommendations for people with type 1 diabetes are the same as for the rest of the population, i.e., a maximum of 14 units per week for men and women.

It is recommended to have two alcohol free days per week. A pint of 4% ale, lager, stout or normal strength beer contains two units, a 250ml large glass of red or white wine is three units and a 25ml shot of brandy, rum, vodka, gin or whisky is one unit.

As a rule, do not count the carbs in alcohol as alcohol may initially raise blood glucose, but overall reduces blood glucose level for a prolonged period after. For this reason, you may also need less mealtime insulin the next day at breakfast if you have had large amounts of alcohol night the before as alcohol can continue to lower blood glucose as alcohol is digested.

You are at more risk of hypos if out dancing and drinking alcohol due to the combination of activity and alcohol. Therefore, you may want to use a sugary mixer in this case to avoid hypoglycaemia.

 

Follow the below advice:

 

You may notice from experience that when you do not count the carbs in alcohol your blood glycose levels are higher afterwards and do not ever come down into a low level. In this case, if you are having the alcohol with a meal, you could consider adding half the carbs in the alcoholic drink to your mealtime carb total.

 

If you have any questions, or if there is anything you do not understand, please contact the Russells Hall Hospital switchboard number on 01384 456111 and ask for the relevant department who issued this leaflet. If you have any feedback on this patient information leaflet please email dgft.patient.information@nhs.net

This leaflet can be made available in large print, audio version and in other languages, please call 0800 073 0510.

 

Originator: Hannah Mconie. Date originated: September 2022. Review date: June 2028. Version:2. DGH ref.: DGH/PIL/02176