Objectives: To evaluate whether a course teaching flexible intensive insulin adjustment can improve both glycaemic control and quality of life in type 1 diabetes.<br /> <br /> Design: randomized design with participants either attending training immediately (immediate DAFNE) or acting as waiting list controls and attending "delayed DAFNE" training 6 months later.<br /> <br /> Setting: Secondary care diabetes clinics in three English health districts.<br /> <br /> Participants: 169 adults with type 1 diabetes and moderate or poor glycaemic control.<br /> <br /> Main outcome measures: Glycated haemoglobin (HbA 1c), severe hypoglycaemia, impact of diabetes on quality of life (ADDQoL).<br /> <br /> Results: At 6 months, HbA 1c was significantly better in immediate DAFNE patients (mean 8.4%) than in delayed DAFNE patients (9.4%) (t=6.1, P<0.0001). The impact of diabetes on dietry freedom was significantly improved in immediate DAFNE patients compared with delayed DAFNE patients (t= -5.4, P<0.0001), as was the impact of diabetes on overall quality of life (t = 2.9, P<0.01). General wellbeing and treatment satisfaction were also significantly improved, but severe hypoglycaemia, weight, and lipids remained unchanged. Improvements in "present quality of life" did not reach significance at 6 months but were significant by 1 year.<br /> <br /> Conclusion: Skills training promoting dietary freedom improved quality of life and glycaemic control in people with type 1 diabetes without worsening severe hypoglycaemia or cardiovascular risk. This approach has the potential to enable more people to adopt intensive insulin treatment and is worthy of further investigation.