Aims: To assess the effect of intensified education on lifestyle (diet, exercise and smoking) as part of an intensified multifactorial intervention over a 4-year period in patients with Type 2 diabetes mellitus with microalbuminuria. Methods: Patients, aged 45-65 years, were randomly assigned either to an intensive group focusing on change of behaviour as well as polypharmacological treatment (n = 80) or to a control group receiving conventional treatment (n = 80). Diet intervention focused on dietary fat and carbohydrate. Food intake was estimated by dietary history interviews and nutrients were calculated from food tables. Exercise and smoking habits were evaluated by interviews. Results: Mean follow-up was 3.8 (SD 0.3) years. The decrease in total fat intake (% of energy intake) was larger in the intensive group as compared to the control group (41.2 (6.2) to 34.2 (6.0) vs. 41.9 (6.5) to 38.3 (6.4)%, P = 0,0001). The decrease in saturated fatty acids (% of total fat intake) was from 47 (4) to 44 (6)% with intensive therapy vs. 45 (5) to 46 (5)%, P = 0.001 and the increase in polyunsaturated fatty acids was from 14 (4) to 18 (6) vs. 16 (5) to 14 (4)%, P < 0.0001. Also the increase in carbohydrate was larger with intensive therapy. However, changes in exercise and smoking habits did not differ between groups. Conclusion: Despite the many resources invested in behaviour modification in this study, only modest changes were obtained in nutrient intake. Further studies are required to determine the best method of inducing long-lasting changes in behaviour in Type 2 diabetic patients.