23,5 kg. an adult being 4st7lb is said to be almost dead - as skinny as possible and therefore the ideal weight for anorexia patients. ROAST BEEF, AS MENTIONED IN 4st7lb, IS THE CHOICE OF PHYSICIANS TO FEED ANOreXIC people AS IT IS HARD TO VOMIT AFTER CONSUMPTION. of all solid food, iT ALSO HAS THE HIGHEST ENERGY GAIN FOR THE AMOUNT THAT HAS TO BE INGESTED.the song 4st7lb is about anorexia. it is written from the VIEWPOINT of an anorexia patient (richey edwards).