Managing food, activity and Type 1 Diabetes: An introduction for newly diagnosed children and families

Type 1 diabetes (T1D) is a condition where the body (pancreas) no longer makes insulin. Insulin has several roles in the body. It is needed to maintain glucose levels in the blood, for building muscle (using protein) and growing.  

Carbohydrate foods are digested and broken down into glucose (glucose is one type of sugar). Glucose is absorbed from the digestive system into the blood stream, which then transports the glucose to all the cells of the body to be used to produce energy. Insulin is essential for transporting glucose into cells.   

Sometimes you will hear insulin described as a key that opens doors to cells. Without insulin, glucose cannot move into cells to be used to produce the energy they need.   

This causes the symptoms of tiredness, thirst, needing to go the toilet lots and losing weight.  

As well as managing glucose levels, insulin is also needed for growing and repairing the tissues of the body.

Type 1 diabetes is managed by replacing insulin, using either insulin injections or an insulin pump, and monitoring glucose levels using continuous glucose monitoring (CGM) systems.  

Insulin should be made by the body (pancreas) all the time – this is background (sometimes called basal) insulin which keeps all the cells working. When food is eaten, or stress causes the glucose levels to rise, the body makes additional insulin to bring glucose levels back into target.  

To copy what the body (pancreas) should be doing: 

• with an insulin pump - we use what is called a hybrid closed loop system, we programme the pump to give a continuous background (basal rate) supply of insulin which is adjusted according to the glucose levels on your sensor, when food is eaten a bolus of fast acting insulin can be given before eating by entering the amount of carbohydrate into the pump.   
• on injections - we use two different types of insulin: a background long-acting insulin, and a fast-acting insulin. Before food is eaten, or when glucose levels are above target, an injection of fast acting insulin is given. The amount of insulin that is needed is calculated using a ‘bolus calculator’ on a phone.

We know that there are some essential steps to managing food, activity and diabetes. It is important to:  

• Eat a healthy balanced diet.
• Be as active as possible every day, 10 -15-minute bursts of exercise before or after meals helps you manage your glucose levels.
• Have a meal routine, three regular meals and only small snacks if needed.
• Always give insulin before food and drinks that contain carbohydrate.
• Use your sensor to check your glucose levels regularly or do at least six finger prick checks a day.
• Learn about how food and activity affect your glucose levels so you can work out your insulin doses to match your food and activity.

Children and young people with type 1 diabetes can eat the same foods as everyone else. Eating a healthy balanced diet with less saturated fats and added sugar, and having more wholegrain foods helps manage glucose levels as well as keeping us healthier for the future. Making sure we don’t eat too much salt and drink plenty of water is also important for being healthy. Treats and sweets can still be eaten as part of a healthy diet, just not too often and always with insulin.  

Choosing healthier food helps to manage blood glucose levels. The foods you eat should provide all the nutrients you need to grow and develop, be a healthy weight and keep your heart healthy. There are no foods that need to be completely avoided, just try to make healthy choices most of the time.   

Foods provide us with:  

• carbohydrate  
• protein   
• fat  
• vitamins and minerals  
• fibre 
• food.

The foods we eat can be divided into five food groups. The Eatwell guide below shows you these groups. If you eat a variety of foods from across the guide, you will have a well-balanced diet. Eat more foods from the bigger sections of the plate. Try to have plenty of starchy foods (yellow), plenty of fruits and vegetables (green), some milk and dairy foods (blue), some protein foods (pink) and some healthy fats (purple).  Carbohydrate is found in foods from all of the food groups. Foods outside of the plate (chocolate, biscuits etc) are not essential to health and should only be eaten in small amounts as treats.  

It is also important to make sure you drink enough water to stay hydrated, this is very important if glucose levels are above target. Follow the advice in the Eatwell guide about how much and what to drink.  

Children and young people need to eat enough to grow properly. The amount you need to eat depends on age, activity levels and gender. You should have 40 - 50% of your total calories (energy) a day from carbohydrate foods. 

The dietitians will give you a guide to the recommended amount of carbohydrate needed a day.

We recommend:  

• Start the day with something for breakfast. Choosing slowly absorbed carbohydrate (low GI) foods helps to manage glucose levels. Include a small amount of protein with breakfast for example a boiled egg, some milk or yogurt.  
• Eat three meals a day which include some starchy carbohydrate foods. Try and include fruit, vegetables and wholegrains as part of your meals. Try to limit processed foods as these tend to be higher in refined sugar and less healthy fats.
• Try and leave a gap of at least two hours in between eating during the day. Try not to eat overnight. Having a balanced meal pattern with a period overnight without food is important for a healthy body weight. Leaving 2-3 hours between food also allows glucose levels to return into range.  
• Avoid drinking milk and fruit juice between meals as these will push glucose levels up. For younger children, avoid drinks just before meals as they will ‘spoil’ the appetite.  
• Limit sweets and treats to after meals and try not to include them every day of the week.   
• Limit eating time at mealtimes to no more than 30-40 minutes.  
• Avoid distractions at mealtimes and if possible, eat as a family.  
• Try not to reward good eating behaviours with food-based treats.  
• Have a regular bedtime – sleep is important for growing and health. Avoid screens before bed/sleep – this helps to get better sleep.

Most of the glucose in the blood comes from the digestion (breakdown) of carbohydrate foods. 

The amount of carbohydrate in a meal or snack influences how much the glucose levels rise after eating.  

The type of carbohydrate will also affect what happens to glucose levels. What else you eat as part of the meal or snack can have an impact as well. 

Insulin needs to be given with carbohydrate containing food and drink. Carbohydrate counting is a way of adjusting fast acting insulin based on the amount of carbohydrate you eat.  

For some meals you may also need to think about the amount of protein, fat and fibre. 

Carbohydrate counting allows you to decide how much carbohydrate food you eat as part of your meal and adjust your insulin dose to match your meal or snack.  

Carbohydrate counting has been shown to improve glucose levels, avoiding high and low levels, and help diabetes management.

The glucose targets we use are between 3.6 and 6.9mmol/L on waking and before eating meals, below 9mmol/L after eating.   

The normal glucose levels for someone without diabetes are between 3.6 and 6.9mmol/L most of the time.  

There is an international standard of time in range. We are aiming for 70% time between 3.9mmol/L and 10mmol/L and less than 4% time below 3.9mmol/L. You will be able to see time in range on your glucose sensor.    

It is important to remember, it is normal for glucose levels to go up and down, people without diabetes do not have 100% time in range, they will still sometimes have low (3.5mmol/L and lower) and high (above 9mmol/L) levels.

It is normal for glucose levels to rise after eating a meal or snack, this happens in people without diabetes. You should expect to see your glucose levels rise after eating. Some foods/meals will cause your glucose levels to rise more quickly than others, some foods will have a late effect on glucose levels. You will see this on the sensor, we can use this information to help adjust insulin doses.  

Your glucose levels should be below 9mmol/L 2-3 hours after meals. Sometimes you may rise above this number.  

We are aiming to keep the rise in the glucose levels after eating below 3mmol/L.  

If your glucose level is rising more than this between 60minutes and two hours after meals/snacks it may be because:  

• The amount of insulin was not enough for the carbohydrate in the meal.  
• The insulin needed to start working earlier before eating.  

If your glucose levels start to rise two hours after eating it may be because of the type of meal you have eaten (the amount of fat or protein in the foods).

Carbohydrates are found in all foods that contain either:  

• starches
• natural sugars (fructose and lactose found in fruit and milk) 
• added sugars (eg sucrose, maltose and glucose.

All types of carbohydrate are digested and broken down to glucose when eaten, except glucose which can be absorbed directly into the bloodstream.  

You need to know which carbohydrate foods you are eating so you can work out your insulin doses.  

• Starches 

Grains; bread, porridge, breakfast cereals, rice, pasta, noodles, flour, quinoa, barley. 

Starchy vegetables; potato, sweet potato, corn, taro, yam. 

Legumes and pulses; baked beans, beans, chickpeas, kidney beans, lentils.  

• Natural sugars 

Fruits; all fresh, frozen and tinned. 

Milk and dairy; milk, milkshakes, yoghurt, fromage frais, Skyr, custard and dairy desserts e.g. rice pudding. 

• Added sugar 

Sugary foods and foods with added sugar; cakes, biscuits, sweets, chocolate, fizzy drinks, sugar, honey, jam, syrup. 

• Foods that do not contain carbohydrate and do not need to be counted 

Vegetables, salad and some fruit; grapefruit, lemon and limes. 

• Foods that do not contain carbohydrate and do not need to be counted but may impact your glucose levels 

Dairy foods; cheese, cottage cheese and eggs. 

Protein foods; lean meat, chicken, fish, nuts, seeds, tofu, Quorn. 

Legumes and lentils eg broad beans, black eyed beans, kidney beans, chickpeas contain small amounts of carbohydrate but may not need to be counted. 

Fats; oils, butter, spreads, lard, ghee. 

What is my portion size? 

For some foods/meals this may be quite easy, for others you may need to weigh your food or use measuring/portion cups  

Look at the two examples of cereal and milk for breakfast. 

Breakfast 1  

Two Weetabix, a banana and milk  

Breakfast 2  

A bowl of cornflakes and milk  

You might need to weigh or measure the cornflakes, banana and the milk to know your portion size. Two Weetabix is more straightforward, the packet will describe a portion as the number of Weetabix.  

For foods you eat regularly it is useful to use measuring cups or pots to make working out your portion size easier.  

We recommend using the weight of cooked food such pasta and rice 

How much carbohydrate is in my portion?    

To work out how much carbohydrate is in your portion you can use a few resources:  

• Carbs & Cals ® book or app (Android or Apple)  
• Food labels  
• Standard portion measures  
• Information from restaurants, food outlet websites  
• Other apps.

We recommend using the Carbs & Cals ® book or app to work out what is in your portion or meal. If you use the app, you can select the food you are going to eat and enter your portion size, the app will tell you the amount of carbohydrate in your portion.

Example: 

You are having 50g Cornflakes and 250ml milk. 

You can use the Carbs & Cals app to calculate the total carbohydrate you are going to eat  

Find your cereal on the app and enter the weight of your portion to calculate the amount of carbohydrate. Add this to the diary.  

You can now add your milk to the diary. Select add to breakfast and then find your milk.

The cereal plus milk contains 54g carbohydrate – this will be used to calculate the dose of insulin for breakfast.  

You can also use the app to:  

• scan barcodes to get carbohydrate information 
• save foods you eat regularly 
• build recipes 
• count carbohydrate for foods bought outside the house.  

The dietitians will provide you with an access code to use the app. 

For video guides on using the Carbs & Cals® app go to https://carbsandcals.com/app/instructions

You can also use the Carbs & Cals® book to work out your meals and snacks – if your portion size is not shown you will need to do some maths.   

We know that doing lots of maths can be the hardest part of managing diabetes.   

This is how we suggest working out what is in a portion of food using the Carbs & Cals® book. 

Carbohydrate you know / portion size you know x YOUR portion 

Example:  

You are going to eat 120g Macaroni Cheese 

Look up Macaroni Cheese in the Carbs & Cals® book. 

• Your portion weighs 120g 
• Carbs & Cals® book tells you that there is 32g carbohydrate in 163g portion of macaroni cheese
• Carbohydrate you know (32g)/portion size you know (163g) x your portion (120g)
• 32 divided by 163 multiplied by 120 = 24g carbohydrate in your portion  

Food labels  

For foods that are packaged and labelled per portion or serving size, food labels can be quick and easy to use. Packaged foods may have two types of label. 

Front of pack labels – these tell you the amount of fat, sugar and salt in a food. They can help you choose healthier foods. They are not used for carbohydrate counting.  

They usually use a red, amber, green traffic light system to help you decide how healthy the food is.  

You can read more about this type of food label and how to use them at https://www.nhs.uk/live-well/eat-well/how-to-read-food-labels/   

Nutrition information label – this will tell you about the amounts of carbohydrate, fat, protein, fibre and salt and other nutrients in the food per 100g and/or per serving.

Tips for using food labels 

• Look at total carbohydrate figure – not ‘of which sugars’ or ‘of which starch’ 
• Check the label is telling you about the food as you will eat it; for pasta, rice, noodles etc. you need the cooked weight.   
• Check your portion size is the same as the one on the label, for example one slice of bread or one biscuit 
• If your portion size is different to the one on the label or there is no portion size you will need to work out from the label what is in your portion.  

This is how we suggest working out what is in a portion of food using the food label 

Carbohydrate you know / portion size you know x YOUR portion 

Example: 

You are going to eat 40g of cereal 

• Your portion weighs 40g. 
• The label tells you that there is 58g carbohydrate in 100g of cereal.  
• Carbohydrate you know (58g)/portion size you know (100g) x your portion (40g).  
• 58/100 x 40 = 23g carbohydrate in your portion. 

Cooked foods  

When you cook a raw food for example rice or pasta or potatoes the weight will change. Foods cooked in water usually weigh more after cooking and foods cooked in the oven usually weigh less e.g., baked potato.   

When you are cooking for a family, it is more practical to work out the carbohydrate from the food after it has been cooked. The Carbs & Cals® book will tell you about food as it is served e.g., cooked pasta and rice.   

Standard portion measures  

Standard measures (portions/cups) can be helpful for speeding up carbohydrate counting of foods you eat regularly.

A standard cup measure is 250ml and a half cup is 125ml. 

You will find a guide to using standard cups measures for carbohydrate counting on the website.  

Eating out  

Many restaurant chains have nutrition information online to help with eating out.  You will also find some of these in the Carbs & Cals app. Research tells us that families who carbohydrate count as accurately as possible at home are able to estimate carbohydrate content of foods eaten away from home.  

We also know that foods eaten outside of the home often contain more fat and protein and they can have a greater effect on glucose levels. You many find meals out need different amounts of insulin compared to when you eat the same foods at home.

How to carbohydrate count a recipe  

Home prepared foods are usually much healthier than shop bought foods as you can reduce the salt, sugar and fat or include extra beans and pulses and vegetables to increase the fibre. We know that carbohydrate counting, and cooking, can feel overwhelming or challenging at first.  

For many foods you will find that the Carbs & Cals® information can be used. If you use the app, enter the weight of your portion of a homemade food to calculate the amount of carbohydrate or you can add all the individual ingredients and save the recipes to the app.  

You can also work out the carbohydrate in your favourite or regular recipes.  The diabetes dietitians can help you with this. 

To work out your recipes you need to.  

1. Identify the ingredients that contain carbohydrate.  
2. Work out the carbohydrate in all these ingredients.  
3. Add the carbohydrate in all the ingredients together to give you the total for the recipe.
4. Divide the total by the number of portions/servings to work out one portion.

Here is an example:

This is a lasagne recipe from BBC Good food which serves six.

Once you have worked out the amount of carbohydrate in your food, you need to work out an amount of insulin to give before you eat.  

To do this you will have an insulin to carbohydrate ratio. We know that the amount of insulin you need with food can vary across the day so you may have a different ratio for different meals.  

An insulin to carbohydrate ratio is always described as 1 unit to cover an amount of carbohydrate, to keep your glucose levels between 3.6 and 9mmol/L in the 2 hours after you eat    

For example: 

• if your ratio is 1:8g, you will need 1 unit to cover 8g carbohydrate 
• if your ratio is 1:12g, you will need 1 unit to cover 12g carbohydrate.  

If two hours after eating, your glucose level is always above or below target you would need to change your ratio.  

You will have a bolus calculator, programmed with your insulin to carbohydrate ratio, which will calculate the insulin dose for you.

Over time, you may need to change the settings in the bolus calculator.  Growing, going on holiday or changing your activity levels are times when your insulin needs change. We can help you change your doses.

Injected insulin  

We will help you to program the bolus calculator app myLife.                                           
This app will work out the insulin doses using the amount of carbohydrate you enter, your insulin to carbohydrate ratio and your glucose levels. 

Use the app to work out your insulin dose and then inject this before eating. Using the app prevents insulin stacking (giving too much insulin). 

You can download this app for Android and iOS devices, from the app store for your phone.  

Insulin pumps

All insulin pumps have a bolus calculator.   

The pump will work out the insulin dose using the amount of carbohydrate you enter, your insulin to carbohydrate ratio, your glucose level, the glucose trend and any delivered insulin. It is important to follow the bolus calculator advice. 

We will show you how the bolus calculator in the pump works.

Why is insulin given before eating?  

To copy what the body should be doing insulin needs to be given before eating (sometimes called a pre bolus).  

When the pancreas makes insulin in response to food, it starts producing insulin before you start eating. Fast acting insulin takes at least 10-15 minutes to start working, so you need to inject or give a bolus with a pump 10-15 minutes or more before you start eating.  

We know that giving insulin during or after eating causes glucose levels to be about 3-5mmol/L higher than if you give insulin before the food and can cause delayed hypoglycaemia.

The glycaemic index (GI) tells us how quickly or slowly a food affects the glucose levels. In other words, how quickly, the body can break down (digest) the food to produce glucose.  

Foods with a very low GI value like beans and pulses may need less insulin than you calculate from the amount of carbohydrate. Foods with a very high GI can be difficult to match with insulin as the glucose rises so quickly. It has been shown that eating more wholegrain, low fat, low GI foods helps give steadier glucose levels in the target range after eating.  

For a recap on your sessions with the dietitian watch this video. 

More information about GI can be found here.

Some foods do not produce glucose when they are digested so we do not count them, but they can impact your glucose levels if they are eaten in large amounts.  

These are foods that are either protein or fat. Eaten in small/normal portion sizes your insulin to carbohydrate ratio will cover the effect they have on the glucose levels. 

High fat and protein meals delay digestion and absorption of carbohydrate and cause some insulin resistance after the meal. Smaller amounts of fat or protein may impact the blood glucose levels of younger children. 

Meals that contain more than 30g fat or 40g protein can cause high glucose levels 3-5 hours after eating and may be tricky to manage.   

High fat and/or high protein meals may require more insulin. 

The Carbs & Cals® book or app can be used to identify these meals. 

Extra insulin can be given if you notice these meals affect your glucose levels. These foods will usually cause the glucose level to rise 2-5 hours after eating and can be more of a ‘problem’ when you eat them in the evening. Not everyone notices this. If you do, contact the diabetes dietitians and we will help you work out how to give extra insulin to better match these foods/meals.

All movement is good. Aim to do at least 10 minutes of activity, you can do lots of 10-minute activity sessions or longer sessions to get to 60 minutes a day. Try to include activities that make you slightly out of breath and your heartbeat faster. We describe this a moderate to vigorous activity. Examples could be brisk walking, a bike ride, or organised sports and activities. 

When we are moving our muscles use glucose for fuel. We store some glucose in our muscles (glycogen) when this is used up glucose moves from the blood into the muscles. After activity our muscles need glucose to replace their stores.

During and after activity we move more glucose into our muscles. This means that being active may lower glucose levels during and after the activity. 

After activity we usually need less insulin, so being active every day can help lower insulin requirements and help glucose levels. For example; if you notice that your glucose levels are high after breakfast (this is quite common) you may find a walk after breakfast helps lower your glucose levels – if you can, walk to school/college. 

Exercise does not always lower glucose levels. It depends on the type of activity you are doing. Sometimes your glucose levels may rise. Keep a record of what happens to you. 

Sometimes when activity is more strenuous it can make managing glucose levels more challenging. We can help you to learn how to manage your glucose levels during sports in one of our exercise and diabetes clinics. 

You will find some helpful explanations of activity and glucose levels on Digibete.  

To get started being active follow these tips: 

• Always wear/carry Diabetes ID. 
• Always have a method of checking glucose levels with you, if you wear a continuous glucose monitoring system carry your glucose meter as a back up. 
• Always check your glucose levels and sensor trend before you start, if you are below 7mmol/L you will need an exercise snack before you start. 
• Carry water and exercise snacks with you. 
• If you have eaten in the 90 minutes before the activity and taken all your usual insulin you will probably need an extra exercise snack (the best snack is fruit). 
• If you are using a HCL system start the activity/exercise mode 1-2 hours before the activity if it is planned or as soon as you start being active if it is unplanned. 
• If you know you are going to exercise/be active after your meal you should take between 25 and 33% less insulin before your meal if you are using HCL or between 25 and 50% less insulin if you are using injections. 
• Try and check your sensor glucose levels every 30minutes during activity – if the glucose level is dropping you will need an extra snack (see table). 
• If you are using an HCL system, stop the activity/exercise mode at the end of the of exercise. 
• If you are doing 60 minutes or more activity in the late afternoon or evening always have some carbohydrate and protein as a pre bed snack e.g. fruit and yoghurt. This snack may need less insulin than usual. 
• Check sensor glucose profiles so that you can learn how being more active impacts your glucose levels. You may need setting adjustmethe glucose levels at midnight and 3am so you learn how activity affects your glucose levels. 
• To learn how being active affects you – check your glucose levels regularly.

Extra carbohydrate snacks can be used to keep glucose levels up during activity, some examples of when you will need a snack include: 

if you have not reduced your mealtime insulin before exercise or you have active insulin and your glucose is in target range. 

if your glucose is between 5 and 10mmol/L, you are going to do an activity for 60minutes or more and your glucose levels are already falling before you start. 

Exercise snack examples: 

• sports drinks (only for activities that last 60minutes or longer) 
• fruit/dried fruit 
• jelly sweets 
• jaffa cakes 
• cereal bars.

If you have had insulin in the two hours before exercising you will need between 7 and 20g carbohydrate to maintain your glucose levels. How much will depend on your glucose level and trends. 

If you are using a hybrid closed loop system start with 7-10g snacks every 20 - 30minutes If you are using injections or a manual pump start with 10-15g snacks every 20 - 30minutes.