Her personality is as sparkling as the sequins on her frocks on Strictly Come Dancing, the show that has been her lifeline since her mother died last year.
There is little doubt Strictly has changed her life. Since she reached the semi-finals last year, Riley has appeared on the Strictly tour, backstage spin-off show Strictly Confidential, is co-presenting the BBC2 strand It Takes Two and will also be hosting the upcoming arena tour.
She has visited schools and dance academies to give motivational talks, and is keen to see dance introduced into the national curriculum.
"My confidence with Strictly rose to gas mark 10," she says. "There had been times when my confidence had been knocked, career-wise.
" For the first time, the press could not turn round and say, 'You are unhealthy'. I ran up them stairs quicker than Robin (Windsor, her dance partner) and he has been dancing since he was five. They couldn't say, 'You're fat and unfit', because I'm so fit.
"Because of Strictly, I was allowed to have this voice, and for the first time in my life I could wear what I liked and I could be sexy."
She is still buxom and bouncy, but there is less of her. She says she never consciously tried to lose weight but the pounds melted away because of the sheer volume of training. She has gone from a size 28 to an 18 in little more than a year and would like to stay there, simply because she feels so fit.
She is now promoting her autobiography, Never Judge A Book By Its Cover, which charts her life from her childhood in Bury and her progression through Oldham Theatre Workshop, which she joined aged nine, to becoming the comical tart-with-a-heart Mandy Dingle in Emmerdale, subsequent roles in Fat Friends, a stage production of Calendar Girls and presenting You've Been Framed, right through to her success on Strictly.
Yet, behind all the smiles, there has been the intense sadness of the death of her mother Cath, who died from breast cancer in July 2012, two weeks before she joined the hit TV dance contest.
During those last months, her mother went from feisty to frail, and Riley nursed her at her own home. She says she now associates being thin with death.
"Me and mum were carbon copies of each other. She was the life and soul and would never have wanted me to sit and throw my head in a pillow and cry, but I was dying inside.
"It was devastating. My whole life just felt like it was over, yet on the other side of the coin my mum knew I had got Strictly and said, 'Darling, just be you', and that's what I did during the series. I went for it."
Riley, 37, says there are still times when she gets lonely, but she tries to surround herself with friends.
"That's probably why I keep myself so busy. The worst times are mornings in my house in Manchester, when I'm pottering around. I can be at my kitchen table and I'll just cry."
Many of her relatives have died from cancer and she is the first to admit she has a worrying gene pool, but she won't let the shadow of the disease stand in her way.
"No, I haven't had any genetic testing to see if I'm more susceptible," she says. "I live every day for today, not longevity. Also, I could get knocked over by a bus tomorrow, so what is the point worrying about it all too much?"
Up to now, boyfriends have not been her strong point. In the book, she reveals her partners have included a fraudster who ended up in jail and a married man who dumped her and returned to his wife. For a while she became the talk of the newspapers, and her confidence hit rock bottom.
"My behaviour was severely denting my career, because I couldn't cope. I didn't want to face being pointed at. I never wanted to be the scandal."
Looking back, she admits she had gone off the rails after joining ITV soap Emmerdale in 1995 when she was 19.
She says she could not handle the fame, and life became one enormous round of drinking and partying.
"At the worst point, I was having five bottles of wine a night and shots. I was verging on alcoholic. I had no 'off button'. I would be sick and then I'd carry on."
Her father brought things to a head when he told her sternly she was a mess and needed to clean up her life. His words prompted her to cut down on excesses.
She has no intention of returning to Emmerdale. "It was my choice to leave. I know you have got people in soaps who have been there for 30-odd years, but to me that's not acting. You might as well work at the HSBC bank."
In the New Year, she will be hosting the Strictly arena tour and is appearing with Martin Shaw in a new series of BBC detective drama George Gently.
"I'm approaching my forties beyond excited, because it's not looking remotely boring."
l Never Judge A Book By Its Cover: The Autobiography by Lisa Riley, available now.