Abstract
We present the case of a young male patient who presented with paralysing muscle weakness due to severe hypokalaemia and hypophosphataemia. The initial patient history evaluations could not establish the aetiology. Only after we reviewed the patient's history did he reveal that he had been following a severe calorie-restricted regime, the human chorionic gonadotropin diet, which had ended 2 days prior to developing symptoms. This information then allowed us to diagnose severe refeeding syndrome. As a further complication, the patient developed rhabdomyolysis. After correction of serum electrolytes, symptoms resolved completely. This case emphasises the potential harm of severely calorie-restricted diets, often recommended by online 'experts'. Furthermore, we underline the importance of thorough history taking.