Amran Ali lost 16 stone (101kg) in just 16 months and in the process reduced his waistline by nearly 20 inches (51cm).
But dieting and exercise played no part in his sudden and dramatic weight loss, because he decided to undergo bariatric surgery.
"I had many health problems, including not being able to breathe when I tried to sleep at night, and not being able to walk very far," said Mr Ali, 51, from Bradford. "I was heading for an early grave and needed help.
"I tried to keep fit and eat more sensibly but I just could not lose those pounds - so I spoke to my kids and decided to take drastic action and have a gastric bypass."
Mr Ali had his operation at the Bradford Royal Infirmary - a designated centre for weight loss surgery.
But despite the city having a very large Asian population, Mr Ali is an unusual case - virtually no-one from the city's Asian communities comes forward for help.
James Halstead, a consultant bariatric surgeon, said by the end of the year the unit will have carried out around 100 operations to help people reduce weight.
He said: "What's really surprising is that out of that figure only three or four were South Asian.
"Based on the numbers of Asian people living in Bradford, they suffer from disproportionately higher levels of obesity - so we should be seeing far more of them in our clinics.
"I believe that many don't come forward for help with losing weight because being overweight is more accepted within the traditional Asian family unit.
"But as a result of being overweight, Asian people suffer from greater levels of illness, such as diabetes, heart disease and kidney problems."
Bradford is due to double the number of gastric bypass and gastric band procedures it will carry out next year.
Each operation costs around £10,000, but Mr Halstead believes it is good value for money because without such an intervention, the NHS would typically spend that amount on an obese patient within just three years.
But other health professionals say having surgery to lose weight should be the last resort.
The Bradford Primary Care Trust says anyone whose BMI (body mass index) is less than 45 will not qualify for surgery.
It says exercise and healthy eating should be encouraged as the first option.
Dr Greg Fell, a consultant in public health for the trust, said: "Surgery is a very effective treatment - but going for long walks and eating a more balanced diet is just as equally effective.
"Going under the knife is not what we would recommend - it is the last resort. Even people who are morbidly obese can reduce weight effectively without having an operation.
"There are risks attached with any type of surgery, and having it will completely change your lifestyle, so think long and hard before you decide to take such a drastic step."
But Mr Halstead said the key was to offer patients a choice, and that bariatric surgery could be a good solution for some people.
He said: "Once the real benefits have been made clear we may start to see more Asian people considering this as a real option to lose weight, and in the process stop other health-related problems."
Mr Ali is convinced his weight loss surgery saved his life. He said its effects had been tremendous.
"Now I can go where I want and do what I have always wanted to do.
"My younger brother is very, very heavy. He has seen my transformation and he is now on a waiting list to have the same operation.
"I know there are risks, and I was aware of them, but I was happy even though I knew I would have to take vitamin tablets for the rest of my life.
"At least that life will now be a lot longer."