Which foods affect my blood sugar levels?
Carbohydrates include starchy and sugary foods (see below). When you eat, carbohydrates are broken down into glucose. This is absorbed into the blood and makes your blood sugar levels rise.
Starchy carbohydrates are an important source of energy and a key part of a healthy diet. It’s important that you eat food containing starchy carbohydrate.
Starchy carbohydrates are also important in preventing your blood sugar level dropping too low. Regular portions of starchy carbohydrates help to keep your blood sugar level constant, because the glucose is released more slowly from these foods than from sugary carbohydrates.
Examples of foods containing carbohydrate
Starchy foods include:
- potato, yam, cassava and plantain
- bread, naan and chapatti
- pasta and noodles
- rice, couscous and quinoa
- unsweetened cereals such as wheat, bran, oats, barley, rye, millet and maize
- crackers and crispbread
- savoury pies and pastries
- breaded and battered food.
Foods containing both starch and sugar include:
- sweet pastries
- sugary breakfast cereal.
Sugary foods include:
- ice cream
- sweets, chocolates and mints
- sugary fizzy drinks and squashes
- fruit juices and smoothies
- syrup and treacle
- jam, marmalade and lemon curd
- condiments including tomato ketchup, chutneys, sweet chilli sauce and brown sauce
- chocolate spread.
Be aware that food and drinks that have a lot of sugar but not much protein, fibre or fat can cause sudden peaks in your blood sugar.
Fruit, milk and yoghurt all contain sugar. But these are different to the sugar in sweets and sugary drinks and they have less effect on blood sugar levels. Fruit, milk and yoghurt also contain other important nutrients and can be eaten often as part of a healthy diet.
Speak to your dietitian if you would like more information about eating food containing carbohydrates.
You don’t need to avoid sugar if you have type 3c diabetes – it can be part of a balanced diet. But a lot of sugar in your diet does make it harder to keep your blood sugar levels within your target range.
You can use sweeteners instead of sugar and choose ‘no added sugar’ options if you want to reduce the amount of sugar you have. Some sweeteners may cause diarrhoea (runny poo), and you should avoid these. Check the brands with your dietitian. ‘Diet’ versions of sugary drinks won’t affect blood sugar levels.
Diabetic foods aren’t recommended. They are expensive and can also cause diarrhoea if you have a lot of them.
Which foods should not make my blood sugar levels rise?
These foods should not make your most people’s blood sugar levels rise or drop:
- meat, fish, eggs, cheese, quorn®, soya protein and tofu
- butter, margarine, lard, ghee, cream, cooking oils and oil-based dressings
- vegetables (except potatoes) and salads
- lentils, beans, pulses, nuts and seeds (although some people may find these do increase blood sugar levels)
- herbs, spices, soy sauce and vinegars
- small amounts of sauces and pickles.
Although these foods may not affect your blood sugar levels, most contain proteins and fats, so you will still need to take pancreatic enzymes when you eat them.