Renee Williams in hospital before her operation
After years of gorging on burgers, French fries and chocolate chip cookies Renee Williams tipped the scales at 64 stone. She was just 29 years old.
The mother of two, who weighed almost half a ton, was bedridden and knew her only chance of survival was to beg doctors for a gastric bypass to reduce the size of her stomach.
Before her death she let cameras into her home in Austin, Texas, to raise awareness of the dangers of obesity.
She said: "I'm not the average overweight person and never have been. My stomach has always been flat and my waist is really small compared to my weight.
"I have to be helped with everything. I can brush my own teeth and comb my own hair but a lot of people who are this weight cannot move around at all."
Renee battled with her weight since childhood but convinced herself her obesity was due to a genetic problem.
She said: "There are times when I have to force myself to eat because I know it's been a while since I've eaten something."
By the age of 12 she weighed 21 stone and was classified as morbidly obese and by the age of 29 was six times the size of a healthy woman of the same age.
Renee married at the age of 15 and weighed more than 30 stone by the time she gave birth to oldest daughter Mirina a year later.
Five years later her weight had soared to 35 stone, but it didn't stop there. At the age of 24, Renee's weight had ballooned so much she had to weigh herself on industrial strength scales at a local garage.
She said: "I was finally able to get the courage up and I asked my mum and sister to go with me.
"The numbers are on this little display not near the scale so I stepped on it but had my sister go and cover up the numbers with her hand because I refused to have anyone else know what I weighed."
In 2003 Renee was left bedridden after a drunk driver smashed into her car crushing her left leg. Unable to control her appetite, she got bigger and bigger and piled on another 28 stone. Renee didn't move from her bed for four years and developed weeping sores all over her skin.
"I can't turn over. My skin has become so fragile when I move my legs too much I feel it rip open," she said.
"You cannot miss it when somebody looks at you and immediately turns to their friend." Although the 840lb mum insisted romance was never been a problem she admitted showing her daughters affection was.
She said: "I want my kids to be able to hug and kiss me. They can't get their arms around me so I settle for a hug around my arm.
"I used to go to the school and see my older daughter in a play. I can't do any of that anymore. I have to see it on video.
"What's kept me going all these years is my daughters. I can't leave my daughters here for something that can be corrected.
"I used to be scared of not knowing what was going to happen to my daughters. I'm afraid of them not having their mum but I'm doing something now that I'm hoping will change that."
Renee's daughter Mirina, 13, said: "I don't know why my mum ate. They told me this has been going on since she was a child. She used to hide food in her closet.
"She ate everything. There was nothing that she didn't like. Her eating habits were getting worse and worse. She wouldn't stop until her stomach started hurting.
"She'd go to McDonalds and get eight burgers from the dollar menu and eat all those."
Renee's sister Lois Quinones added: "I don't know what was going on with her psychologically. She really did want to eat all the time because she didn't feel full.
"After her accident she was a different person. She was bedridden at 26 and I think she used food to comfort a lot of that isolation, loneliness and knowing that was her future."
When doctors gave Renee less than a year to live she knew a gastric bypass was her only chance at life but was turned down by 12 hospitals across America because of her size.
The determined mum chose to take matters into her own hands and launched an online appeal for help.
She said: "One day my heart is just going to stop beating. It's going to say I'm tired of pulling this body around. That's it."
Surgeons at Houston's Renaissance Hospital heard Renee's appeal and admitted her for the operation.
Renee was the largest person ever to have the surgery and had to be carried from her bed to an ambulance by eight men.
The operation was a success and within two weeks Renee had lost four stone. Tragically however Renee suffered a huge heart attack and died on March 4, 2007.