It has been suggested that much effort expended in teaching diabetic diets is ineffective and wasteful. We have tested a different system by randomly allocating 75 newly diagnosed obese Type 2 diabetic patients to usual 'unstructured' clinic care or to group education by diabetes specialist nurses and a dietitian. Patients allocated to group education attended five 90-min group sessions during the first 6 months. Six months after diagnosis they had lost more weight (median (95% Cl), 7 (5.5-9) vs 2(1-5)kg, p less than 0.002) and were better controlled (HbA1:7.5 (7.0-8.1) vs 9.5 (8.7-10.4)%, p less than 0.001) than those randomized to the usual clinic system. At 1 year (after no further visits) the difference in weight loss was less (5.5 (4-6.5) vs 3 (2-4) kg, p less than 0.05) and diabetic control was similar (HbA1:9.0(8.2-9.8) vs 9.9(8.9-10.9)%. At 1 year only 14(39%) of the education group and 9(23%) of those attending the clinic had a fasting blood glucose less than 7.0 mmol l-1.