What is diabetes?

Diabetes (diabetes mellitus) is a condition caused by the failure to regulate blood sugar in the body. The hormone insulin is key to managing the amount of sugar (glucose) in the blood. If a gland called the pancreas does not secrete enough insulin or the cells of the body become resistant to the effects of insulin, blood sugar levels will not be controlled the way they should be.


Without the proper functioning of insulin, sugar cannot enter muscle or fat cells, this may cause serious secondary complications including heart disease, stroke, kidney disease, neuropathy and other complications.

This article is not intended as medical advice. If you’ve been diagnosed with diabetes, speak to your GP or a registered dietician before making any changes to your diet.

Diabetes food and monitoring equipment

How many types of diabetes are there?

Typically, diabetes is split into two main types, however, research has progressed over recent years with some research suggesting diabetes may be seen as five separate diseases – this study potentially paves the way for more personalised treatment. However, while these results look promising, further research is necessary before changes may be made to the way diabetes is managed. Currently, the NHS classifies diabetes in two main types, these are:

  • Type 1 diabetes is an insulin dependent condition, this is less common and usually develops before the age of 30. This occurs when the pancreas stops producing insulin. The exact cause is unknown, but some believe it is an autoimmune response in which the body attacks its own pancreatic cells. People with type 1 diabetes need to take insulin for life.
  • Type 2 diabetes is a non-insulin dependent condition, originally more common in later life, it is now increasingly prevalent in younger generations. In Type 2 diabetes, the pancreas still produces insulin, but either it's not producing enough or the body does not respond to it properly. The most common cause of type 2 diabetes is being overweight or obese.In many cases, Type 2 diabetes can be avoided by eating a healthy, balanced diet and taking regular exercise, it may often be managed in the same way if diagnosed. However, some cases will require medication and your doctor should be the one to determine whether this is appropriate.

Does my weight matter?

Research has reported interesting evidence to support the reversal of type 2 diabetes, funded by Diabetes UK and performed by a team at Newcastle University the study reported that type 2 diabetes may be reversed by an extremely low-calorie diet (600 kcals per day). New findings from a 3-year extension of the study has since reported that nearly a quarter (23%) of participants who were in remission from type 2 diabetes at two years in the original trial, remained in remission at 5 years.

This diet is extreme, and Diabetes UK strongly recommends that such a drastic diet is only undertaken under professional medical supervision. People with diabetes who want to lose weight should consult their GP before undertaking any new eating plan.

What is gestational diabetes?

Gestational diabetes is a type of diabetes that affects women during pregnancy, these women have slightly higher than normal levels of glucose in their blood and their body cannot produce enough insulin to transport it all into the cells. You can find out more about this condition from the NHS on gestational diabetes.

Male doctor and child with diabetes

What are the symptoms of diabetes?

These can vary from tiredness, thirst, frequent urination to skin infections and cuts and wounds that take longer to heal.

A full list of symptoms can be found at diabetes.co.uk.

What are the health implications of diabetes?

People with either type 1 or 2 diabetes have a higher chance of developing a range of health conditions including heart disease, stroke, high blood pressure, circulation problems, nerve damage and damage to the kidneys and eyes.

If you are overweight or obese then losing this excess weight healthily and steadily may have a very positive effect on blood sugar levels and may reduce the risk of developing Type 2 diabetes. If you already have type 2 diabetes losing weight may mean you need fewer or no medication for your condition and you will reduce your risk of cardiovascular disease.

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It's also important to build exercise into your routine, as this will help support your body in its ability to maintain stable blood sugar levels. Simply increasing your step count may lower blood pressure and improve blood sugar levels. Read our guide to find out more benefits of regular walking.

Will I need special diabetic food?

No – foods labelled as being ‘suitable for diabetics’ have no special benefit for people with type 1 or 2 diabetes.

What are the best food choices for diabetics?

Eating a healthy, balanced diet is key to managing both type 1 and type 2 diabetes, and this still means you can enjoy a wide range of tasty foods.

The dietary guidelines for those with diabetes are the same as those recommended for a healthy lifestyle: eat less sugar and fat, include more fibre-rich starchy foods and more fruit and vegetables with moderate amounts of meat, fish, milk and dairy. Choosing the right foods may make a big difference and timing your food, so you are eating regularly, may also help avoid blood sugar fluctuations.

Sugar cubes over pink background

Is there a diet I can follow for diabetes?

As our knowledge of the condition has evolved so too has the dietary advice – this has changed from following a low-GI diet and carb counting to adopting a Mediterranean-style diet.

However, current thinking is that the best diet to follow is a healthy, balanced one that includes fruit and vegetables, lean protein sources, wholegrains and other fibre-rich foods. Be sure to include a wide variety of the foods you specifically enjoy, but pay attention to those that affect your blood glucose levels.

It’s important to remember that all carbohydrates are broken down to provide energy in the form of glucose – these include starchy carbs like bread, rice and potatoes, and sugary carbs such as biscuits, jams and sugary drinks. When choosing carbs, consider the type and the portion size – opt for wholemeal or wholegrain options, wherever possible. These are especially good sources of fibre that may slow the rate at which the starch and sugar from carb foods enters the bloodstream. Fibre may also help manage cholesterol levels and keep you fuller for longer – when increasing the fibre content of your diet, do so gradually to allow your body to adjust to the change.

Don’t forget to maintain your hydration levels with water, herbal teas etc. but minimise your consumption of squash and sugary drinks.

Are there foods or drinks I should avoid if I have diabetes?

Diabetes is linked to a higher risk of heart disease so the same heart-healthy dietary advice applies. To find out more, read our helpful guide on heart disease.

In addition to this:

  • Minimise white, refined carbohydrates and enjoy more foods with a low GI instead.
  • When buying processed / packaged foods check labels and be sure to understand which ingredients will influence blood sugar levels – these include ingredients ending in '-ose' as well as additives like maltodextrin.
  • If you choose to drink alcohol, avoid drinking more than the recommended amount, and never drink on an empty stomach. Don’t forget alcohol has the ability to cause high or low blood glucose levels (hyperglycaemia or hypoglycaemia) and drinking alcohol may affect your ability to carry out insulin treatment or blood glucose monitoring, so be careful not to drink too much.

Need recipe inspiration? Try these…

Avocado & black bean eggs
Chicken jalfrezi
Mushroom & thyme risotto
Falafel burgers
Chocolate & berry mousse pots
All our diabetes-friendly recipes

For help managing your weight, check out our Healthy Diet Plan.

For further advice or information regarding the diagnosis or management of diabetes, please consult your GP and ask for a referral to a registered dietician.

Have you been diagnosed with diabetes? How do you manage your condition? Share your experience in the comments below…

Jo Lewin is a registered nutritionist (RNutr) with the Association for Nutrition with a specialism in public health. Follow her on Twitter @nutri_jo.

Kerry Torrens BSc. (Hons) PgCert MBANT is a registered nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food. Find her on Instagram at @kerry_torrens_nutrition


All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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