A consultation with a dietician is needed so that patient learns to: 1. identify low glycaemic index food, 2. limit the intake of high glycaemic index food especially between meals | High-calorie, low glycaemic index foods should be favoured (oleaginous foods, rice pudding, complex carbohydrate-lipid mixtures etc.…). | Insulin therapy and self-monitoring must be adapted to suit the patient's dietary habits (small, frequent meals rather than few, large meals a day and gastrointestinal GVHD modulating digestive tolerance | If weight loss, food supplements for diabetics can be prescribed. |