A British woman who paid close to $5,500 for invasive weight-loss surgery was surprised to learn the 84 pounds she lost was purely through exercise, the Daily Mail reported.

Karren Knight, 47, who weighed close to 308 pounds, had a gastric band fitted around her stomach in order to lessen her appetite.   She then took up dancing and noticed her body start to slim.

After a routine checkup two years later, her doctor revealed that the gastric band was broken and had never actually worked.

Knight had lost the weight all on her own.

“I thought it was impossible for me to lose weight by myself,” said Knight, who lives in Widnes, Cheshire in England.  “I’d spent years going on diets, and nothing worked.”

Knight’s band was supposed to be filled with saline to shrink her stomach.  But the band had always been leaking, so it did not work.  After fixing the band, Knight lost a another 126 pounds.

Now a Zumba instructor, Knight takes eight-hour classes each week and teaches weekend classes to help others lose weight.

She also advises others to become more active before they pay for weight-loss surgery.

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