National audienceThe holy month of Ramadan is characterized by abstinence from eating and drinking from dawn to sunset. This dietary practice entails profound changes in life style habits. The sunset meal (Iftar) that breaks the fasting state is usually followed by exaggerated surges in blood glucose, which can further result in overnight sustained hyperglycemia in case of nocturnal overfeeding. The latter is usually related to additional food intakes that can be provided as either a dinner taken 2 or 3 hours after the sunset meal or intermittent repeated snacks, and sometimes as a combination of both of them. Throughout the nocturnal period, the cumulative consumption of carbohydrates including the predawn meal (Sohour) can reach a level as high as 500 grams. In such situations, it is not surprising that the glycemic control of persons with diabetes, especially of those treated with insulin, shows marked disturbances during Ramadan. In many patients, the exaggerated loads in calories and carbohydrates result in body weight gain. Analyses of marketed food supplies confirm this overconsumption and thus this overfeeding. Consequently, both dietary measures and pharmacological glucose-lowering treatments are not easy to handle during Ramadan. The most appropriate attitude would be to convincing persons with diabetes for being exempted from religious fasting when the following conditions are not fulfilled: compliance to a nutritional program and acceptance/understanding of a structured and personalized therapeutic regimen. Assignment to a tight self-monitoring of blood glucose should be recommended at least in those requiring multiple daily injections of insulin. Patients who do not comply to such requirements are at risk for acute adverse events (severe hyperglycemia and/or hypoglycemia) during the Ramadan period. In addition, there arises the question as to whether a 1-month excess in glucose exposure every year for several decades has or not the potency to exert a deleterious « legacy impact » on the long-term development and/or progression of chronic diabetic complications.Le mois religieux du Ramadan est caractérisé par l’abstention de toute consommation d’aliments ou de liquides du lever au coucher du soleil. Cette pratique modifie de manière considérable les habitudes alimentaires. Le repas de rupture du jeûne (Iftar), souvent riche en glucides rapides, entraîne, chez les patients diabétiques, une brusque montée de la glycémie, qui peut conduire à une hyperglycémie soutenue et chronique sur l’ensemble de la période nocturne si le repas de rupture du jeûne est suivi soit par un dîner consommé 2 à 3 heures après, soit par plusieurs collations, soit par les deux à la fois. Si l’on inclut le repas pris avant l’aube (Sohour), la consommation cumulée de glucides sur la période nocturne peut atteindre les 500 grammes. Dans ces conditions, il n’est pas étonnant que l’équilibre glycémique des patients diabétiques, en particulier de ceux qui sont insulino-traités, soit profondément perturbé pendant le Ramadan. Chez de n...