Type 2 diabetes is the most common form of diabetes in the UK, and symptoms may include feeling very thirsty, urinating more frequently than usual and blurred vision, before diagnosis.
Medication may be required as the condition progresses, but making simple lifestyle changes to your diet and exercise routine help control your blood glucose levels.
Bupa says eating carbohydrates can make your blood sugar shoot up, so counting and using a glycemic index can be useful.
Matthew Freeby, MD, director of the Gonda Diabetes Center at UCLA Health, says one particular food that falls into the carbohydrate category should be avoided all together.
Speaking to Prevention, Mr Freeby said popular breakfast item, the bagel, should be crossed off the menu.
He explained: “Many of my patients with diabetes think about sugar as being the worst thing that’s impacting their blood sugar, but it’s really about carbohydrates.
“I tell them to look at nutrition labels for the total carbohydrate content, not just the sugar content.
“Donuts and bagels made with refined and processed grains are major sources of blood-sugar-spiking carbs.”
Diabetes UK says the key to managing and preventing diabetes is a balanced diet.
Fruit and vegetables
Whether it’s fresh, frozen, dried and canned fruit in juice and canned vegetables, everyone should eat at least five portions a day, says Diabetes UK.
The charity suggests adding an apple, banana, or orange to your child’s lunchbox, eating sliced melon or grapefruit topped with low-fat yoghurt, or a handful of berries, or fresh dates, apricots or prunes for breakfast, and eating carrots, peas and green beans mixed up in a pasta bake.
Try and include starchy foods every day.
You could try potatoes any way you like, with the skin left on for valuable fibre, covered in a low-fat topping such as cottage cheese or beans. But don’t fry the potatoes.
Two slices of multigrain toast with a scraping of spread and Marmite or peanut butter, and rice, pasta or noodles in risottos, salad or stir-fries are some other options.
Meat, fish, eggs, pulses, beans and nuts
You should aim to have some food form this group every day, and at least one to two portions of oily fish a week.
Protein helps build muscles, the minerals found in these foods help with the production of red blood cells and omega-3 can help protect the heart.
Eat meat, poultry or a vegetarian alternative grilled, roasted or stir-fried, or eggs scrambled, poached, dry fried or boiled.
A small handful of raw nuts and seeds as a snack or chopped with a green salad are also an option.
Diabetes UK also recommends what dairy foods you should eat.