Obesity surgery and Ramadan: a prospective analysis of nutritional intake, hunger and satiety and adaptive behaviours during fasting.

Background: Fasting for religious or lifestyle reasons poses a challenge to people who have undergone bariatric surgery. A total fast (abstaining from all forms of nourishment including liquids) during long summer days puts these patients at risk of dehydration and poor calorie and nutrient intake.

Methods: We undertook telephone surveys of 24-h food recall, hunger and satiety scores, medication use, adverse symptoms and depression scores on a fasting day in Ramadan and a non-fasting day subsequently.

Results: We studied 207 participants (166 women) who had undergone sleeve gastrectomy. The mean (standard error) age was 35.2 (0.7) years. Men and women consumed 20.4 % (P = 0.018) and 16.9 % (P < 0.001) fewer calories and 44.8 % (P < 0.001) and 32.4 % (P < 0.001) less protein during fasting, respectively. There was no significant difference in the intake of fluids or incidence of adverse gastrointestinal, hypoglycaemic and sympathoadrenal symptoms. Of participants on pharmacotherapy, 89.5 % took their prescribed medications; 86.3 % made no changes to the doses, but 80.4 % changed the timing of the medications. Both women and men reported feeling less hungry and a preference for savoury foods during Ramadan. There was no difference in depression and work impairment scores.

Conclusions: Fasting was well tolerated in persons who had undergone sleeve gastrectomy. It may be advisable to raise awareness about dietary protein intake and managing medications appropriately during fasting.