William Hill have presented Sheffield-based family doctor Libby Collins with the windfall after she staked £50 at odds of 50-1 in a bid to inspire her patients to lose weight.
The 37-year-old mum - who dubbed herself the 'fat GP' - wanted to become a role model for overweight patients at her practice in a deprived part of the city.
Her last attempt to use betting as an incentive led to her gaining a stone, but this time the Rivelin medic overhauled her lifestyle and improved her diet.
She wanted her healthy regime to be achievable for patients at her Foxhill surgery who are on limited budgets, so introduced sensible meal plans and increased her activity levels.
A fitness tracker helped her to hit a benchmark of 10,000 steps per day and she started to make better food choices.
"I am a busy mum-of-two and wanted to lose the weight with sensible eating and increased activity," said the 5'5'' doctor, who previously weighed 18 stone.
"I wanted to do it that way, so I could tell my patients it can be done as I work in quite a deprived area of north Sheffield and people die eight to 10 years younger than those in more affluent areas due to health inequalities. They also don’t have a lot of spare cash, so expensive diet plans and gym memberships are no good.
"My patients quite enjoyed coming to see the ‘fat GP’ and they would say 'oh, you know how hard it is to lose weight' and I was making them feel better about not achieving their goals. I want to turn that around and show them they can achieve their goals.
Dr Collins had been suffering from migraines, and she comforted herself by snacking on sugary foods and takeaways before she and her husband Peter, a librarian, made radical changes to improve their health and that of their children Winifred, six, and Humphrey, two.
"Now we have changed the way we cook, using less fat and grilling foods, so the usual advice that I would give to any patient. My tastes have changed a bit too and I've reduced the proportion of dairy and increased alternatives like oat milk and coconut-based yoghurts.
"I have to fit in with the rest of the family and my work schedule, so I've got no time for faffing about making separate stuff. We eat normal family meals but adapted to be healthier options."
She has found that NHS weight loss programmes run by her surgery have much better success rates than initiatives to stop smoking.
"With smoking you can advise 100 to 150 people to stop and your success rate is that one will do it, but with weight loss if a doctor advises 12 patients they should lose weight then you will get one who will listen. That is a much better rate of return for the NHS.
"For me this hasn't been about aesthetics or self-esteem, which I understand are factors which impact on many people's relationships with food and their weight and should be tackled sensitively.
"I have been worried about the impact of my weight on my health and I didn't want to be in a position where my patients might think 'well if my GP can't do it, what chance do I have?'
"Obesity is a major health problem. If you are overweight or obese and feel it is the right time to lose weight there is lots of help available. Check your GP's website for what is available locally to you. You do not necessarily need to see your GP. There may be information available via your surgery to aid you to make this change yourself.
"If you are overweight or obese reducing your weight is one of the most beneficial things you can do to improve your health. The benefits go so much further than the reduction in the risk of heart attack, stroke, or diabetes and such like. I feel 10 years younger. I have more energy, I'm more productive, I love the feeling of being able to get out and use my body whilst it is able. I can go for walks and connect with nature, or have a run and burn off any stress.
"If all of these benefits were available in tablet form I suspect I would be out of a job, and a pharmaceutical company would be very happy, but nobody has managed to combine the dual effects of weight loss and exercise in such a format. Yet you can do it yourself, and it is free!
"I have been various degrees of overweight and obese for the past 20 years and there will be plenty of people watching to see if I revert to type. And that says more about them than it does about me. But I have been asked 'why didn't you do this years ago?' There are lots of answers I could give. It isn't as though I haven't started every year thinking I would try.
"It can be frustrating being in a cycle of attempting the same feat repeatedly and failing but it is only really a failure if you don't learn anything from it.
"In January 2016 I asked myself realistically, what needs to be different this time, in order to succeed? My answers will be different to any other person's but it is a worthwhile task if you find yourself thinking 'not another new year diet plan'.
"The weight loss didn't happen overnight. I didn't lose five stones in one go. I did it one pound at a time, one step at a time, by building new habits. I work full-time hours and don’t have additional child care, so not a lot of free time to go to the gym, but if I can do it working 12-hour days anyone can.
"I still have two to three stones left to lose and I know I can do it now because I've shown that I can. When I look at photos from a year ago I can see the difference. I have a desk job, but I am always on my feet doing stuff, so much so that they laugh at me running about at work.
Dr Collins plans to spend her winnings on water sports for her family in the Isle of Wight in the summer.
Dr Collins's diet before:-
Breakfast - cereal, mini Weetabix or muesli (large portion), or toast with butter and Marmite
Elevenses - fruit and yogurt
Lunch - chicken salad, pasta with sauce. Often if there was any meeting, celebration, there might be lunch/onion bhaji/samosas/wraps or cakes/crisps provided so would eat those on top of whatever I had taken.
Later in afternoon - run to shops for snacks - bag of crisps, full sugar drink, if feeling stressed bag of chips. Lots of tea/biscuits.
Tea - Often oven-baked foods e.g. lasagne, cottage pies, baked potatoes, regularly takeaways.
Dr Collins's diet now:-
Breakfast - porridge with oaty milk
Mid-morning - piece of fruit/coconut yogurt
Lunch - veg soup (homemade), or roasted veg and couscous, or mixed bean salad
Mid-afternoon - cottage cheese/nuts/fruit. The practice manager keeps a well-stocked fruit bowl and if I look tempered to go in the biscuit tin she is the first person to give me a healthy get out, which I always gratefully accept.
Tea time - normal family food - but cooked more healthily. We don't omit any food groups and try to eat a wide range e.g. Spanish omelette and salad, pasta dishes, fish, sausage casserole.