Diabetes has become a major threat to public health. It is one of the major causes of premature illness and death in most countries, and is becoming more common. There are two main types – type 1 and type 2. Around 2.5 million people in the UK have diabetes, most of which is type 2. It is also estimated that up to 750,000 people may have type 2 diabetes without knowing it. Type 1 diabetes (insulin-dependent diabetes) is an auto-immune condition in which the immune system of the body turns against itself, causing permanent damage to particular cells in the pancreas that produce insulin. Insulin production ceases. Type 1 diabetes is managed by injections of insulin coupled with a healthy diet. Type 2 diabetes (non-insulin dependent diabetes) occurs when the body does not produce enough insulin or the insulin produced does not work properly (this is known as insulin resistance). It is typically associated with being overweight or obese. Diet modification and physical activity are the two main approaches to treatment of type 2 diabetes. Eating a healthy balanced diet, taking regular physical activity, and maintaining a healthy body weight can help to prevent or delay the onset of type 2 diabetes. People with diabetes should try to maintain a healthy weight and eat a diet that is low in fat (particularly saturates) and salt but contains plenty of fruit and vegetables (at least five portions a day) and starchy carbohydrate foods such as bread, rice and pasta (particularly whole-grain versions).