Inclusion Criteria:  Post-bariatric surgery patients (Roux-en-Y gastric bypass) with PBH, defined as postprandial plasma or sensor glucose <3.0 mmol/L according to the International Hypoglycaemia Study Group and exclusion of other causes of hypoglycaemia Age ≥18 years  Exclusion Criteria:  Inability to give informed consent as documented by signature Pregnant or lactating women Inability or contraindications to undergo the investigated intervention Drugs interfering with blood glucose (e.g. SGLT-2 inhibitors, acarbose) during the time of investigation Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc.