Diabetes, which affects nearly three million people in the UK, is caused by low levels of insulin, a hormone that is responsible for controlling blood sugar levels.
In Type 1 diabetes the body's immune system attacks the cells that produce insulin.
People with Type 2 diabetes don't produce enough insulin. When no insulin is produced increased glucose levels can damage vital organs. The good news is that healthy eating can balance blood sugar levels. Here are some top tips.
Foods containing large amounts of slowly absorbed carbs produce a steady rise in blood glucose with a relatively low peak.
These foods are said to have a lower glycaemic index (GI) rating.
Foods containing high levels of simple sugars, such as mashed potato and white bread, produce a more rapid rise and a higher peak in blood glucose. These foods have a higher GI rating.
Choosing slowly absorbed carbs helps iron out peaks and troughs in blood glucose.
EAT: Apples, oranges, pears, beans, durum wheat pasta, sweet potatoes, sweetcorn, porridge, All-Bran, Special K and wholegrain breads.
Some studies suggest that B12 improves diabetic neuropathy (damage to nerves caused by high blood sugar levels) and reduces pain and paraesthesia (sensations such as tingling, burning, prickling and pins and needles). Oily fish, seafood, meat, eggs, milk and poultry all containvitamin B12.
Vitamin C may reduce the formation of a sugar called sorbitol linked to retinopathy (damage to the retina), neuropathy and kidney damage.
EAT: Raw cabbage, carrots, lettuce, onions, tomatoes and all citrus fruits.
Chromium, found in whole grains, egg yolks, mushrooms and meat, boosts the action of insulin and helps the body use protein, fat and carbohydrates effectively.
In some animal studies chromium supplements prevented the development of diabetes. Other studies suggest that an intake of 400mg of magnesium a day seems to reduce the risk of developing diabetes by about 33 per cent. EAT: Nuts and beans.
Wholegrains (the seeds of cereals such as wheat, brown rice and maize) are a good source of fibre and contain 75 per cent more nutrients than refined cereals.They also seem to reduce the likelihood of developing diabetes.
For example, men who ate on average 10.2g of cereal fibre a day were 30 per cent less likely to develop Type 2 diabetes than those who ate just 2.5g a day.Despite these benefits 95 per cent of adults in the UK don't eat enough whole grains.
EAT: oats; wholewheat flour, bread and pasta; brown or basmati rice; and pearl barley. (The Daily Express)