Fasts after bariatric surgery

The requirement to observe a total fast (all forms of nourishment including liquids) during daylight hours in the month of Ramadan poses a great challenge in the management of people who have undergone bariatric surgery.1 Bariatric surgery is increasingly performed for the correction of morbid obesity, particularly in people with comorbid conditions such as diabetes.2 Most bariatric procedures limit the amount of food or drink consumed in one sitting, so patients are advised to sip fluids frequently throughout the day. A total fast during long summer days would put these patients at risk of dehydration. Long fasts could lead to the desire to eat larger amounts more quickly on breaking the fast. This could cause vomiting, compounding dehydration and poor nutritional intake. Foods commonly eaten at the sunset meal, such as sweets and deep fried pastries, would also put some patients at risk of dumping syndrome or steatorrhoea. The small stomach volume might make it difficult to fit in nutritional supplements and drugs around meal times.

Research in this area is virtually non-existent. On the basis of clinical experience we recommend that patients avoid total fasts in the first 12-18 months after bariatric surgery; after this, the risk of postprandial vomiting is reduced and otherwise healthy patients may observe religious fasts if fluids are taken throughout the day (for example, fasting during Lent). In addition, advise patients to base meals on complex carbohydrates and high quality proteins, and advise those who have had malabsorptive procedures such as gastric bypass to continue taking nutrient supplements.