Staff at the Happy Cottages Phuket on Soi Ta-ied found Adam Arthur Sahyoun, 31, dead, lying face-own on the floor at about 4:45pm, and called police.
Mr Sahyoun arrived in Phuket on July 5 and was due to fly home on August 5. He was estimated to weigh about 200 kilos, and medication and syringes found in the room indicated he was suffering from hyperinsulinemia, a condition closely linked with obesity with can lead to cardiovascular disease.
Investigators believe that he had been dead for about eight hours when he was found.