The Rovers Return favourite says she is comfortable with her looks. 'I’m happy where my body is now, I’m never going to be, or want to be, skinny.'
Catherine, 29, who plays Eva Price in Coronation Street was once a size 22 and 15 stone. She is now a svelte four-and-a-half stone lighter.
Lovely in lemon: Corrie star Catherine Tyldesley shows off her svelte figure
Big girls do cry: Corrie actress Catherine admits to overeating to combat her depression
'And exercise raises endorphins, which make you feel happy,' she told Star magazine.
'I just feel an all-round improvement and hopefully people can relate to me.'
Catherine keeps exercise a priority and works hard with personal trainer Nick Mitchell.
'He’s very mean – but he’s very good at what he does! We do weights and interval training together.'
'I wanted to shop in the same places as my friends and wear clothes like them but I was too big. That’s why I want to help people.'
To keep her figure in tip-top condition, Catherine doesn't eat processed foods or junk foods.
Instead, she sticks to eating a lot of green veg and protein.
However, she doesn't cut out carbohydrates completely.
'It’s how I’ve managed to keep the weight off this time around,' she says. 'Fad diets don’t work.'
Before Catherine shed the weight, the actress admits to being very unhappy, over-indulging in comfort foods like cake and pizza.
'Yes, it was a really, horribly depressing time.All my friends were lean and athletic, and I was huge.'
We're not together: Wearing a tight-fitting scarlet dress, Catherine Tyldesley with her ex-boyfriend Sam Witter
There is so much pressure on young women to go on diets and not eat properly.
Speaking out: Lisa opens up to this week's Star magazine about her body and health
But Catherine has no intentions of giving up her favourite treats, and believes it's important to keep fun and happiness a top priority.
'You’ve got to be able to have a bit of chocolate and enjoy yourself,' she says.
'I would never deprive my body of what it needs. Health and happiness are key.'
The Manchester-born star is also determined not to be bullied by Twitter trolls who blasted her for posting pictures of herself in the gym.
She laughs it off by saying: 'I just thought the pictures were funny as I looked like a sweaty Betty!
'I only did it for my Twitter followers, as I get really sad letters from women who are desperate for weight-loss advice.
’I’m into positive energy and anyone that’s negative; that’s their issue.'
The busy actress has been spending her free time catching up with friends and having fun since splitting from her boyfriend.
There’s no hard feelings with her ex, as she explains, 'Sam’s still a lovely guy and he can do what he wants. We’re not together.'
Corrie star: Playing Eva Price, Catherine has a strop with Stella Price (Michelle Collins) in the Rovers Return