A primary school teacher gained so much weight after succumbing to a late-night 'marking diet' of pizza and garlic bread that she almost lost her sight.
Bethan Goodhew thought the headaches and dizziness she was suffering were down to work-induced tiredness and stress.
But after having recurring bouts of giddiness and loss of vision after getting up off the floor or from sitting down next to infant-sized chairs, Bethan sought medical advice.
The 26-year-old from Clwyd, North Wales saw her optician and then a neurologist, who gave her a startling diagnosis.
She was suffering from benign intracranial hypertension, a rare condition where fluid pressure builds up in the skull, squashing the optical nerve, which then interferes with eye and brain function.
The condition is linked to weight, although the exact cause is unknown. At the time of her diagnosis, Bethan weighed in at 25 stone.
"It was terrifying. I went to the opticians thinking I might end up getting some new glasses, then I was told it could be cancer and sent for scans. That freaked me out," she told the Mirror.
"When someone is telling you there is something wrong with your brain, it's the scariest thing you can hear.
"When I went to see the neurologist, he told me I could lose my vision – intrcranial hypertension could be deadly."
The neurologist told her that if she lost weight it could help to relieve the pressure.
The doctor suggested Bethan underwent bariatric surgery and with the support of her family, who helped raise the cash for procedure, Bethan checked in to the Spire Weight Loss clinic in Wrexham in December 2011.
Surgeons carried out a gastric bypass and re-routed her digestive system so she could only eat small meals and feel full sooner.
Bethan replaced her usual fatty diet with with fruit, salad and pasta and lost 11st in just 16 months.
She now weighs 14st and is a size 14 – and the pressure and swelling in her brain has reduced.
"I feel so much better than I did before," she said. "Not only has losing the weight cured me of intracranial hypertension, it has also helped with my wellbeing and confidence."