Photo: SEVENTY-stone woman once dubbed the 'half-ton killer' loses an incredible 80% of her bodyweight

A woman who was once dubbed the ‘half-tonne killer’ after she falsely confessed to accidentally killing her nephew has lost 800lb.

Mayra Rosales said she had given up on life when she decided to protect her sister Jamie and take the blame for the death of her nephew Eliseo in 2008.

Rosales, 34, from Texas, told police she had smothered the child by rolling on top of him.

The claim was later disproved when autopsy results revealed the boy had died from multiple injuries to his skull.

After her sister Jamie confessed to the crime and was sentenced to 15 years in prison, Mayra vowed to get healthier to take care of her sister’s surviving children.

She decided to turn her life around and since 2011 has been shedding hundreds of pounds.

With the help of 11 surgeries, including a lap band surgery and extra skin removal procedures, she managed to lose the weight.

She also changed the way she thought about food, she told ABC 13.

‘Food to me is I have to eat to live,’ she said. ‘Before it was living to eat, and now you know, it’s just something normal.’

Houston surgeon Dr. Younan Nowzaradan said he could see Rosales was driven to make a change.

‘Once you’re in bed for several years, she had no life,’ he said.

‘Once she got up and walk and do things, you’ll be amazed how motivated people become.’

Rosales now has an active following on Facebook with over 18,000 fans, who she keeps updated as her transformation continues.