Fasting during Ramadan is one of the five pillars of Islam, and all healthy adolescent and adult Muslims are obliged to refrain from eating and drinking from dawn to sunset during this lunar month. The fast may last 11–20 hours, depending on where and at what time of year Ramadan occurs.
People with long-term conditions such as diabetes are not obliged to fast, however, many still choose to fast. Most people with type 2 diabetes can fast safely with appropriate medical advice and management before and during fasting. However, people with type 1 diabetes need special attention, and pregnant women with diabetes are advised not to fast.