Mother of two, Karren Knight, lost six stone following a £3,500 gastric band operation, only to discover the band had snapped and the weight loss was all down to exercise.
The 47-year-old, who weighed 22 stone, saved up for the expensive surgery after years of fruitless dieting.
After having the gastric band fitted to restrict her appetite, Knight took up dancing to take her mind off binge eating.
She was pleased to see her figure slim down and deemed the operation to be a success.
But when she went for a check-up two years later, doctors revealed her gastric band was leaking and had never worked and that she had lost all the weight herself through exercise.
The mother from Widnes, Cheshire, expressed her shock, as reported in the Daily Mail:
"I thought it was impossible for me to lose weight by myself - I’d spent years going on diets and nothing worked.
"It was a vicious cycle, that I thought could only be cured by surgery.
"I was moaning one day to my sister, Paula, and she suggested I get a hobby to take my mind off food - and I went along to a zumba class that had just started up down the road.
"The weight soon started to drop off - but I was convinced it was mostly because of the band."
After discovering the band, filled with saline, had been leaking Karren returned to Belgium, where the procedure had taken place, for corrective surgery.
After the band was fixed she went on to lose a further nine stone.
Now, at just nine stone, Karren spreads the word on the slimming powers of dancing by working as a Zumba instructor.
She said, as cited in the Daily Mail: "As I got older, and had my children, it was always an effort to keep the weight off, and I went from being chubby to being massive.
"I thought surgery was an easy way to lose weight - but I’ve discovered all it took was a bit of determination and finding some exercise I enjoyed."
She added: "I’d advise anyone who is considering weight loss surgery to really think twice about it. I didn’t realise how dangerous it could be, and as it turns out, I didn’t really need it to lose weight.
"I’m so happy now - not only do I have the body of my dreams, I’m much fitter, happier and healthier, and I have a great new career too. My confidence is through the roof."