Jo Bradley, aged 41, piled on the weight after her mother, Ann, had a sudden fatal heart attack when she was just 47.
Ms Bradley, from Farnworth, sought comfort by bingeing on crisps, bread, cheese and massive portions of food.
But as she approached 40, weighing more than 23 stone and wearing a size 30, she was terrified she would not be around to see her daughters Lucy, aged 16, and Megan, aged 10, grow up.
She tried many diets and medication from her doctor, but once she came off them the weight piled back on.
So in May, 2011, when she was asked by her daughters’ dance instructor to try out a new Zumba class at Angels Dance and Fitness in Farnworth, she gave it a go and has since dropped down to a size 16.
“My weight crept up on me in my early 20s. One day, when I was 21, I was having a conversation with my mum and she dropped down dead of a heart attack.
“She was really big. At the time it was horrific. That sent me on a spiral and I ate for comfort.
“I didn’t realise it was depression at the time. Mum was my best friend and I had no one to speak to about it. I am on my own so, if anything like that happened to me, what would happen to my kids?”
Within 10 years, Ms Bradley had piled on the pounds, but she struggled to keep any weight she lost off permanently.
“I was even prescribed a tablet from the doctor, which means that you can’t eat anything that is more than four per cent fat as it would make you very ill. I lost a couple of stone, but then put it back on once I came off them.”
But after starting the Zumba class in 2011, she has not looked back.
She said: “I went with some friends and I loved it. It’s about finding what you want to do and what you enjoy.”
Now Ms Bradley weighs in at 14st 12lbs — a size 16 — and has lost 8st and 2lbs in total.
She said: “I feel so much better. Someone said to me I have shrunk in size and grown in confidence. Before the weight loss the only place I could shop was Evans, Now I’m a 16.”
“I remember the day Megan said to me: ‘Mummy, I can fit my arms around you now.’ I nearly cried I was so happy.”
Melissa Finbarr-Smith, dance instructor at Angels, added: “I’m proud of Jo. She’s done it all by herself, through Zumba, without going down fad diets.”