Full written instructions will be provided to the family for all aspects of the insulin dosing for the study meals. During the study on the standardised meal days children will be instructed not to eat any food after the meal during the evening, and not to correct any later BG levels unless they are dangerously high (BG over 16 mmol/l with ketones over 0.5 mmol/l). If BG levels go low at any time (BG less than 4 mmol/l) children will be instructed to treat the hypoglycaemia according to their usual management. This data will be analysed separately. Children and families will be asked to complete diaries during the trial week.