In 6 normal weight juvenile diabetic patients treated with continuous subcutaneous insulin infusion (CSII) we have investigated whether the restrictive management of the diabetes diet could be relaxed. On 2-3 days of a 4 week period the patients ate a) a conventional diabetes diet consisting of 3 main meals and in-between snacks of a prescribed carbohydrate content or b) a liberal diabetes diet in which the patients could choose the number of meals and carbohydrate contents. With both diets, mean blood glucose levels during the day were in normal range (96 +/- 3 and 101 +/- mg/dl, mean +/- SEM). On the liberal diet meal frequency and carbohydrate intake per day were significantly lower, the carbohydrate content per meal significantly larger when compared with the conventional diabetes diet. There was not difference in insulin requirements per day (basal rate plus premeal dosage). All the patients preferred the liberal diet. CSII allowed juvenile diabetic patients a more liberal management of their diabetes diet without negative effects on blood glucose control. Hence CSII improved the quality of life in these patients.