Pauline Quirke felt compelled to take "drastic action" in her weight battle after realising she was just a few pounds lighter than a sumo wrestler.
The Emmerdale star has long struggled with her weight and decided to embark on a new healthy routine in the summer of 2010.
Pauline ditched the treats, ate healthily and took up exercise, but Christmas proved her downfall as she tucked into all her favourite foods, prompting her weight to jump to 20 stone - and this led to a nasty accident.
In her new book Where Have I Gone?, she explains: "I'd had a lovely meal out with the Emmerdale cast and crew. There had been a lot of snow and ice and as I got out of a cab I fell over, bringing all 20 stone down on my left arm.
"I was in agony. I hit rock bottom. All the fight had gone out of me. Everything I'd planned crashed into a flaming great chasm - the diet, the diary, the training, my goal to get fitter and my plans for a new me."
However, Pauline decided to take action again after watching a TV show about sumo wrestlers.
The 52 year old adds: "I watched a TV programme about a sumo wrestler who weighed 20 stone. So, I was just a few pounds lighter than a sumo wrestler. Now there's an image that doesn't make you feel terribly attractive. I needed drastic action."
She embarked on the LighterLife diet plan, in which meals are substituted for low calorie food packs, and she hasn't looked back.
Now a size 12/14, Pauline says: "I made a decision that I would not keep hold of any of my bigger-sized clothes - 'just in case I grew back into them'. It was all going: the comedy fat-suit dresses, the two million oversized black vest tops.
"My clothes weren't the only thing that changed. When we went on holiday to Majorca last summer, I could wear a swimsuit and... I wanted to walk. Palma, like many beautiful cities, is all about walking, and previously this was something that hadn't been easy.
"Now I was exploring the city. We walked all round the magnificent Cathedral of Santa Maria, which is all steps and steep climbs, and I loved it. I made a trip to the gym every day, too. There was less of me, let's face it, and so it was a darned sight easier. When I was 19st 6lb, I was exhausted after about five minutes; now I was feeling a lot more confident."
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