:A S clock:'Diet or die,' worlds fattest woman is warned after hitting FIFTY STONE Last updated at 1:39 PM on 9th December 2010 A woman believed to be the world's fattest at 50 stone (700lbs) is facing a battle to shed weight after being told by doctors she could die. Terri Smith is confined to her bedroom in her Ohio home unable to move, stand or roll over by herself. Suffering from severe headaches which doctors fear could stem from a brain problem, Terri urgently needs a brain scan - but is too big to fit inside an MRI machine. Huge problem: Terri Smith, pictured in her bed with medication, is facing a battle to lose weight so she can fit in an MRI machine To undergo the scan and receive the life-saving treatment she may require, Terri is now embarking on a weight loss regime of exercise and healthy eating. She relies on her husband Myron, 44, and oldest daughter Najah, 30, to do everything for her. The 49-year-old must be washed, fed and dressed on the bed and wears nappies which her daughter and husband change. 'My husband is my guardian angel,' said Terri. 'He's stuck by me through everything. Most men would have left a long time ago and who could blame them but Myron is a living saint.' Terri was always large - at age seven she weighed almost eight stone (112lbs). 'My nickname at school was fatso,' she said. 'No one wanted me on their sports team and that didn't help the fat. 'We grew up on soul food and no one thought anything about it. Devoted: Terri with loving husband Myron who changes her nappies 'That's just what people did where I'm from. We never watched what we ate at all and we didn't know what was healthy and what wasn't.' By the age of 20 Terri weighed 18 stone (252lbs) but she remained active and held a job as a mental health care worker for 20 years. 'I used to help people wash, feed and dress themselves,' she said. 'Back then I never thought that the tables would turn and someone would be doing all that stuff for me.' After marrying her husband in 1986 Terri was big but happy. 'I prayed for a man like Myron and he came to me,' she said 'He's kind, gentle and he loves me for who 'I am. Even now he tells me I'm pretty, that man is amazing.' But she continued to eat the same diet and kept on growing, while her husband and daughter stayed slim. Terri, who suffers severe headaches, needs an MRI scan to check for a potential brain tumour but is too big to fit in any scanners or into the doors of a hospital clinic. Younger: Terri, left, with friends as she was growing up She faces a race against time to lose weight in a bid to qualify for gastric surgery to save her life. When Terri was 32 she developed severe arthritis in her knees and couldn't walk for more than a few steps. She was given an electric wheelchair and the lack of exercise made the weight pile on. 'I used to walk everywhere and be on my feet at work but suddenly I was trapped,' she said. As the years passed her weight ballooned until she could hardly stand. Then, after her doctor changed her diuretic medication, she gained a staggering 6.5 stone (91lb) in 30 days. She suddenly found herself bedbound and has been trapped for almost three years. Dr. Dariush Saghafi said: "I have been seeing Terri for six months. 'Caring for someone of Terri's size is very difficult. It is very hard to move and transport her. Hospitals do not have equipment to hold someone of her girth. Grandmother: Terri with her grandchildren Jurnee Weeams, eight, (right) and Najeir, seven 'Terri needs an MRI but there are no machines in the region big enough to take her weight. 'We thought that it might be possible for Terri to have an MRI at the Cleveland Zoo in the machine used for the elephants and rhinos but the zoo does not have a licence for humans. 'We're hoping the Cleveland clinic can find an MRI for Terri.'