For many of us carbohydrates are a key source of energy. Carbohydrate-containing foods also provide important nutrients for good health.
All the carbohydrates you eat and drink are broken down into glucose. The type, and amount, you consume can make a difference to your blood glucose levels and diabetes management.
In this guide:
- Types of carbohydrates
- How much carbohydrate do I need?
- How much carbohydrate does food contain?
- Quality of carbs
- Carbohydrate and type 1 diabetes
- Carbohydrate and type 2 diabetes
- Wholegrains and diabetes
- Alternatives to carbs
- What is resistant starch?
Types of carbohydrates
There are different ways to describe carbohydrates. One way of doing this is to group them into those that contain mostly starch (such as bread, rice, pasta, potatoes, yams, plantain, breakfast cereals and couscous), and those that contain mostly sugars, such as fruits (fructose), some dairy foods (lactose), sweets, chocolate, sugary drinks and desserts.
Fibre
Fibre is another type of carbohydrate, which you can’t digest. Fibre is found in wholemeal bread, brown rice, wholegrain cereals, fruits and vegetables, nuts and seeds, pulses, potatoes, oats and barley.
Fibre helps keep our digestive system healthy, and can also help to manage blood glucose and cholesterol. Make sure you eat enough fibre every day as this is associated with a reduced risk of cardiovascular diseases and certain types of cancers.
How much carbohydrate do I need?
Everyone needs some carbohydrate-containing foods in their diet. The actual amount that you need to eat will depend on your age, activity levels and the health goals you are trying to achieve.
For example, one person trying to lose weight and manage their blood glucose levels by using a low-carb diet would restrict their carb intake, while another person who is very active and maintaining their weight may decide to eat more healthy carbs.
The total amount of carbohydrate consumed will have the biggest effect on your glucose levels after eating, so being able to estimate carbohydrate quantity is helpful. However, not everyone with diabetes needs to restrict their carb intake.
How many carbs are in your food?
Many people with diabetes will count or estimate the amount of carbohydrate they are consuming.
If you use insulin to treat your diabetes, you may be on a basal-bolus insulin regime - this is when you take a basal background or slower-acting insulin once or twice a day and bolus or faster-acting insulin with meals. Estimating the amount carbs you consume helps you to know how to adjust the amount of bolus insulin to give with meals.
If you are on fixed insulin doses, consuming consistent amounts of carbs can help manage blood glucose levels. Having an awareness of carb-containing foods and drinks, and portion sizes, can also help with managing body weight for some people.
You can learn about which foods contain carbohydrates, how to estimate carbohydrate portions and how to monitor their effect on blood glucose levels. There are special courses available, such as the DAFNE course for people with type 1 diabetes, which your diabetes healthcare team can tell you about.
What about the quality of carbs?
Evidence shows that the quality of the carbohydrates is more important to general health than the amount we eat.
Generally, foods lower on the Glycaemic Index (GI) – which tells us whether a food raises blood glucose levels quickly, moderately or slowly - can be useful for managing blood glucose levels.
More importantly for overall health, choosing foods that are high in fibre and wholegrains instead of refined carbs, such as white bread, is better for our heart health and reducing our risk of certain types of cancers.
We also know that some specific carb-containing foods, such as fruits and vegetables and dairy, are associated with good health.
Ways to include good quality carbohydrates in your diet:
- Choose wholegrain breads and cereals.
- Have fruit whole, rather than as a juice. Eating an apple with the skin on, for example, will provide more fibre than drinking a glass of apple juice.
- Try grains like couscous, quinoa and bulgur wheat to add more variety to your diet instead of carbohydrates such as white pasta and white rice.
- Try sweet potatoes for an interesting change from white potatoes. They have a sweeter taste and creamy texture and taste delicious baked with the skin on.
- Try seeds, nuts and pulses as lower-carb sources of fibre.
- Choose unsweetened milk and yoghurts.
How does carbohydrate affect someone with type 1 diabetes?
All carbohydrate is converted into glucose. In someone without diabetes, the body produces insulin automatically to deal with the glucose that enters the blood from the carbohydrate-containing food that we eat and drink.
In type 1 diabetes the same principle applies, but because the body doesn’t produce any insulin, someone with type 1 diabetes must take insulin, either by injections or an insulin pump. This will help to lower the glucose in the blood after eating carbohydrate-containing foods. Most people follow twice-daily or basal-bolus insulin regimes.
Twice-daily insulin
If you are taking fixed amounts of insulin twice a day you may find it beneficial to have consistent amounts of carbohydrates on a day-to-day basis, and eat roughly the same amount of carbohydrate at similar times each day. This means estimating how much carbs are in the individual foods and meals you eat to get the amounts right.
Consuming more carbohydrate than usual can cause blood glucose levels to go too high, and consuming less than usual can cause a hypo (low blood glucose levels).
Basal-bolus insulin
If you are using a basal-bolus insulin regime by injecting several times a day, or through an insulin pump, you can be much more flexible in how many carbs you eat and when you eat.
Most people following this regimen will count carbohydrates that they eat and drink and then calculate how much insulin they need to take. The amount of insulin will change depending on how much carbohydrate they’re eating.
Other factors are also important, such as any physical activity you have done or plan on doing, as well as any previous episode of hypos, and any infections.
Read more about the different types of insulin
How does carbohydrate affect people with type 2 diabetes?
For some people with type 2 diabetes, following a low or lower carb diet has helped them to lose weight and manage their diabetes including lowering their HbA1c, cholesterol and blood pressure as well as reducing the amount of diabetes medications they take.
If you are taking diabetes medications that put you at risk of hypos, checking your blood glucose levels regularly and speaking to your healthcare team to review your medications will help to reduce your risk of hypos when you restrict your carb intake.
What are wholegrains?
Wholegrains are the seeds of cereal plants such as wheat, maize, corn, rye, barley, oats, rice and quinoa. In their natural unprocessed state, grains consist of three parts:
- the endosperm - the central part of the grain and is a concentrated source of starch
- the bran - the outer most layer, this is a rich source of insoluble dietary fibre, B vitamins and phytochemicals
- the germ - a concentrated source of protein, ‘healthy’ fats, B vitamins and vitamin E.
When wholegrains are refined, for instance to make white flour, most of the bran and germ are removed and with it most of the nutrients, dietary fibre and other protective components, which are concentrated in the bran and germ layers.
Wholegrain foods, retain all three parts of the grain. They may be eaten whole (eg brown rice and oats), cracked (eg bulgur wheat), or milled into flour and made into foods like bread and pasta. To qualify as a wholegrain, a food must contain 51% or more wholegrain ingredients by weight per serving.
Why are wholegrains a healthy choice?
Wholegrains are a smart choice, not just for people with diabetes, but for the whole family.
If you live with diabetes, wholegrain foods are usually better for managing blood glucose levels because they tend to have a lower GI. This means they do not affect blood glucose levels as quickly as refined carbohydrate foods.
However, since wholegrains are also carbohydrate foods, and all carbohydrates affect blood glucose levels, be mindful of your portion sizes.
Wholegrain foods are associated with a reduced risk of heart disease, stroke, certain types of cancer and type 2 diabetes.
The ways in which wholegrains help prevent these conditions are not fully understood. They can play a part in maintaining a healthy body weight over time as part of a healthy, balanced diet and help keep your gut healthy due to the compounds they contain called phytochemicals.
Studies also suggest that wholegrain foods may be more filling than their refined counterparts, which may help reduce the urge for snacking between meals and help people manage their weight.
How much wholegrain should we eat?
In the UK there are no official recommendations, but most experts recommend at least three servings of wholegrains a day.
However, wholegrains are a good source of fibre and adults should be aiming for 30g of fibre per day. Many of us do not consume this amount.
It’s important to replace refined products with wholegrain foods to help manage your blood glucose, and for overall health.
One serving of whole grains equals the individual equivalent of:
- 25g porridge oats
- 1 bowl (34g) muesli
- 1 bowl (30g) toasted wholegrain oat cereal
- 1 bowl of wheat-based breakfast cereal
- 1 bowl of breakfast cereal made from wholewheat
- 1 large slice (40g) multi-grain bread
- 23g (uncooked weight) brown rice
- 23g (uncooked weight) wholewheat pasta
- 3 Rye crackers
- 3 oatcakes
- 1 slice of rye bread
- 1 wholemeal pitta bread
Are there gluten-free wholegrains?
If you follow a gluten-free diet there are plenty of gluten-free wholegrains that you can enjoy such as brown rice, quinoa, uncontaminated oats, millet, sorghum, teff and buckwheat.
What’s the difference between wholemeal, wholewheat, wholegrain and granary bread?
Wholemeal, wholewheat and wholegrain bread are basically different terms for the same thing and all are wholegrain.
However, granary bread is slightly different and refers to bread that contains malted wheat flakes that are added to give it a characteristic texture. This may or may not be made from wholemeal flour, so you will need to check the label.
Wheat-germ bread is made from white flour to which a portion of wheat germ has been added back, it is not wholegrain.
How to eat more wholegrains
There are plenty of simple and tasty ways to introduce wholegrains into your diet.
- Choose a wholegrain cereal for breakfast.
- Swap white bread for wholemeal bread – look for the words ‘wholegrain’ or ‘wholemeal’ on the label.
- Choose brown rice instead of white – look out for brown basmati and quick-cook brown rice.
- Use wholemeal flour for baking – if you’re not used to baking with wholemeal flour start by substituting half the white flour with wholemeal. As you get used to cooking with wholemeal flour you can gradually increase the proportion.
- Choose oatcakes, rye crackers, or wholemeal crackers instead of cream crackers.
- Swap couscous for bulgur wheat.
- Add barley to soups and stews.
- Popcorn is a wholegrain so as a treat swap crisps or other savoury for unsalted sugar-free popcorn.
- Corn on the cob is wholegrain, or you can add sweetcorn to recipes like spaghetti bolognese or chilli con carne.
- Use porridge oats in crumble toppings.
- Add wholegrains, such as quinoa to salads for texture, and to boost the protein and fibre content.
- Blend wholegrains in burgers or use them directly as a meat alternative, or combine them whole in baked goods.
Cooking with grains
Cooking most grains is very similar to cooking rice – simply add the dry grain to a pan of water or broth, bring to a boil, then turn down the heat and simmer until the liquid has been absorbed. For a healthy boost of nutrients, experiment with different grains in different forms to bring variety to your meals.
Try our range of wholegrain recipes to up fibre and nutrients in your diet:
- Chicken biryani
- Very berry porridge
- Barley mushroom risotto
- Rice and beans
- Apple and raisin muesli bars
- Quinoa stuffed squash
- Pepper and tomato bulgar wheat salad
- Spinach, corn and chickpea fritters
- Herby stuffed aubergine
Alternatives to carbs
Instead of sticking to pasta and rice, try these recipes for vegetable alternatives to rice and pasta, which will help you to cut down on your carbohydrate portion sizes – if you need to – as well as adding to your five a day:
Cauliflower rice
- Take one head of fresh cauliflower (or however much you want) and break it into florets.
- Using a cheese grater, shred it until it looks like normal rice. If you have a food processor, you can use the plain steel or shredder blade to save time.
- Either microwave it in a covered dish (you don’t need to add water), steam it, or fry it in a little oil or low-calorie spray.
Courgette pasta
- Chop off the top and bottom of the courgette and, using a vegetable peeler, cut strips off the whole of the length. (For nice, thick slices, press the peeler down harder than you would when normally peeling fruit and veg.)
- Bring a small pan of water to the boil and then drop in the strips.
- Cook for up to 1 minute, then drain well.
- Season with pepper, if you wish.
- You could also try using slices of marrow in place of some of the pasta sheets when making lasagne.
What is starch and resistant starch?
Starch is the most common carbohydrate in our diets and is essentially a chain of glucose molecules linked together.
Raw starchy foods (e.g. raw potatoes) have a highly ordered structure and are hard to digest, but heating them in water weakens this structure, making it easier for the gut to break down each chain and absorb glucose into the blood.
Glucose from cooked starchy foods, such as white rice, pasta and potatoes, is absorbed almost as quickly as glucose from a sugary drink. We say these foods have a high GI.
However, when starchy foods are cooled their structure is reorganised again and the digestive enzymes in your gut can’t break them down as easily.
The food now contains more ‘resistant starch’, which is not broken down and essentially becomes fibre. There is a small amount of research that suggests when cooled starchy foods are reheated, more resistant starch is created.
What are the health benefits of eating resistant starch?
If you swap a meal made with normal starch for one made with ‘resistant starch’ it can positively impact glucose levels.
‘Resistant starch’ increases the fibre content of your diet without affecting the appearance, taste or texture of the food and without you knowing the difference. Foods fortified with ‘resistant starch’ can give you the fibre equivalent of brown rice, brown bread or wholemeal pasta without changing your diet. One short-term effect of this is that it helps you feel fuller for longer after a meal.
However, it is important to note that the overall quality and quantity of carbohydrates in your diet have the biggest effect on blood glucose levels and overall health.
Healthy swaps for resistant starch
Try these simple healthy swaps to get more resistant starch into your diet without changing what you eat:
Instead of: | Try: |
Hot pasta with sauce | Cooked and cooled pasta in a pasta salad |
Hot, boiled new potatoes | Cold, boiled new potatoes as part of a green salad |
Overripe bananas | Slightly underripe bananas (green-yellow) |
Fresh bread | Frozen and defrosted bread |
Diabetes UK’s clinical advisors recommend…
Foods that include resistant starch can be part of a healthy balanced diet and allow individuals to incorporate more fibre into their diets. It is very important to follow food safety guidelines when cooling, storing and reheating foods in order to minimise the risk of potential food poisoning.
