A woman who was so fat she could barely walk is running the London Marathon - after losing half of her body weight.
At her largest Judi Heykoop weighed a huge 27st and was a dress size 32 through a teenage addiction to food which saw her consume 4,000 calories a day.
Every day she ate on five bowls of cereal for breakfast, pizza and chips for lunch and a huge meal for dinner.
Fighting fit: Judi Heykoop will be running in her first marathon when she takes part in Sunday's Virgin London Marathon after losing thirteen-and-a-half stone, half her body weight
She would also snack on up to ten donuts a day - plus whatever else she could get her hands on.
She was at her biggest by the age of 24 when doctors warned her life expectancy was 54 unless she did something drastic about her weight.
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Judi, now 28, tried a series of diets and saw a hypnotist but without success and as a last resort her GP eventually offered her a gastric bypass on the NHS.
The £10,000 operation removed part of her digestive system so she now only absorbs around 50 per cent of the calories she eats.
Before and after: Judi ballooned to a huge 27st and size 32 through a teenage addiction to food but has since lost half her body weight
Challenge: Judi has already completed a couple of half-marathons and on Sunday faces her biggest test yet with the full event - setting herself a target time of under five hours
She had the bypass in 2009 and has been on the road to fitness ever since.
For six weeks after the operation Judi, who is 5'11", lived off baby food as she could only eat liquidised meals.
But the pounds started to fall off and in the first four months alone she lost five stone and was down to size 20 clothes.
As she lost weight she felt less sluggish and decided to start exercising and in 2010 joined the British Military Fitness group whose instructors are serving or former members of the armed forces.
They keep Judi in shape with gruelling outdoor exercise classes and she quickly lost another two stone and also acquired a passion for running.
Big eater: Judi had an addiction to food which saw her consuming 4,000 calories a day. Every day she gorged on five bowls of cereal for breakfast, pizza and chips for lunch and a huge meal for dinner
Big appetite: She would also snack on up to ten donuts a day - plus whatever else she could get her hands on, doctors warned her that her life expectancy was 54
She now jogs three times a week, has joined a mountaineering club and has lost over 13.5st to slim down to a size 14-16, tipping the scales at 13st 7lbs.
Judi has already completed a couple of half-marathons and on Sunday faces her biggest test yet with the full event - setting herself a target time of under five hours.
She will be cheered on by her family, friends and boyfriend as she raises money for mental health charity MIND.
Judi, a management consultant from London, said: 'I couldn't be happier.
'When I look at old photos of me I feel ashamed that I let myself get so big - I really had an addiction to food.
'I was eating a massive amount of carbohydrates and would buy boxes of donuts and give my friends a couple and eat the other 10 myself.
'I was struggling to walk and tried everything to lose weight but nothing worked until the bypass.
'My friends and family never thought I'd run anywhere, let alone complete a marathon and I'm determined to reach the finish line.'
Last resort: Judi, now 28, tried a series of diets and saw a hypnotist but without success and as a last resort her GP eventually offered her a gastric band operation