ADDITION Plus is a study involving patients within the intensive treatment programme of the ADDITION study in Cambridge and patients with diabetes recently diagnosed by their doctor in general practices in Cambridge and surrounding counties. In addition to their treatment programme, half of the patients were given additional support and advice to encourage changes to lifestyle. The aim was to help patients achieve sustained changes to their physical activity and diet, to support cessation of smoking if applicable and to help patients to take their medication as prescribed. The other half of the patients were not given any additional support. The four behaviours (physical activity, diet, smoking and adherence to medication) were measured along with other measures such as weight, blood pressure, blood glucose and cholesterol after one year and five years.