This documentary follows a small number of British people with an incurable genetic disease called Prader-Willi syndrome. This rare disorder makes the sufferer unable to control their eating habits. Prader–Willi syndrome is a rare genetic disorder in which seven genes (or some subset thereof) on chromosome 15 (q 11-13) are deleted or unexpressed (chromosome 15q partial deletion) on the paternal chromosome. The film is set in Gretton House, near Kettering in England, which is a government-funded care home deliberately constructed to assist people with PWS. The film focuses on a new resident, Joe Blackburn, who is 21 and begins the documentary weighing over 30 stone (190 kg, 420 lbs) and with fears for his health. Resident Tamara Allwood is also featured, who was at one point close to death from overeating.