RT Journal Article SR Electronic T1 Features of a successful therapeutic fast of 382 days' duration JF Postgraduate Medical Journal JO Postgrad Med J FD The Fellowship of Postgraduate Medicine SP 203 OP 209 DO 10.1136/pgmj.49.569.203 VO 49 IS 569 A1 Stewart, W. K. A1 Fleming, Laura W. YR 1973 UL http://pmj.bmj.com/content/49/569/203.abstract AB A 27-year-old male patient fasted under supervision for 382 days and has subsequently maintained his normal weight. Blood glucose concentrations around 30 mg/100 ml were recorded consistently during the last 8 months, although the patient was ambulant and attending as an out-patient. Responses to glucose and tolbutamide tolerance tests remained normal. The hyperglycaemic response to glucagon was reduced and latterly absent, but promptly returned to normal during carbohydrate refeeding. After an initial decrease was corrected, plasma potassium levels remained normal without supplementation. A temporary period of hypercalcaemia occurred towards the end of the fast. Decreased plasma magnesium concentrations were a consistent feature from the first month onwards. After 100 days of fasting there was a marked and persistent increase in the excretion of urinary cations and inorganic phosphate, which until then had been minimal. These increases may be due to dissolution of excessive soft tissue and skeletal mass. Prolonged fasting in this patient had no ill-effects.