Objectives: Severe hypoglycemia characterized by neuroglycopenic symptoms is a recently described and relatively uncommon complication of gastric bypass surgery in chronic kidney disease (CKD) patients. It occurs several months to years after surgery and may be distinct from the more commonly encountered dumping syndrome that occurs early in the postoperative course and usually improves with time. Postprandial hypoglycemia is an infrequent but disabling complication of Roux-en-Y gastric bypass (RYGB) surgery. Dietary restriction (DR), often referred to as calorie restriction (CR), denotes limiting calorie intake by an individual. To evaluate the daily life efficacy of a calorie -restricted dietary advice (CRD) of 5 meals per day with a 30 g carb maximum per meal in CKD patients with documented post-RYGB hypoglycemia. Methods: Frequency and severity of hypoglycemic events before and after CRD were assessed retrospectively in 38 CKD patients with documented post-RYGB hypoglycemia, based on medical records and telephone questionnaires. Hypoglycemia was defined as a blood glucose level<3.0 mmol/L. Results are expressed as mean values±standard error or median and range. Results: CRD decreased the number of hypoglycemic events per month from a decline of 87% (P<.001). The lowest blood glucose measured during a hypoglycemic event increased significantly (P<.001). The number of CKD patients who had required outside help in the treatment of hypoglycemia, significantly decreased (P<.001). In 11 patients the diet-induced reduction of hypoglycemia was insufficient and required the start of insulin suppressive therapy. Conclusions: A CRD, consisting of 5 meals per day with up to 30 g carbs each, is an effective treatment of post-RYGB hypoglycemia in the majority of CKD patients. Additional medication is needed in about a third of patients. The pathophysiology of this disorder is primarily due to RYGB anatomy resulting in altered glucose, gut, and pancreatic hormone levels and decreased insulin clearance, rather than -cell hyperplasia.