Malnutrition affects up to 30 % of the general population, and especially older people with polymorbid conditions. In parallel, the prevalence of diabetes increases with age affecting over 800 million adults worldwide. Healthcare providers are increasingly challenged to care for patients with diabetes that require nutritional support. To address this issue, the ESPEN Special Interest Group "Nutrition and Diabetes", aims to provide guidance for health care providers that treat these patients. This paper had three aims: 1) to summarise the guidelines and recommendations regarding nutritional support and diabetes or stress hyperglycaemia provided by scientific societies, 2) to review the associations of nutritional disorders with diabetes and its pharmacological treatments, and 3) to identify the challenges of optimal nutritional care for patients with diabetes and stress hyperglycaemia. To this end, we conducted a systematic search of guidelines and recommendations on nutritional support for patients with diabetes or stress hyperglycaemia, that have been published in English by national and international societies over the last 15 years. Our systematic search showed that published guidelines and recommendations rarely addressed the practical management of blood glucose control according to the modality of nutritional support. The literature on the association of malnutrition with diabetes and its pharmacological treatment is very limited. The identified challenges include the multidisciplinary and multiprofessional continuity of care between the hospital and ambulatory settings, the ideal pattern of hospital food, the choice of oral nutritional supplements, the adjustment of diabetes management to nutritional support, and diabetes technology to support nutritional care in these patients.