After years of yo-yoing, Natalie Cassidy insisted last month that she’d finally reached a healthy weight she could maintain after losing more than a stone in six weeks.

Flaunting her hard-won size 10 body on a beach in Tenerife last week in our exclusive pictures, the mum-of-one looked completely comfortable in her bikini.

And sources say that it appears Natalie has beaten her weight demons for good – swearing off faddy diets and losing another 5lbs since December, telling pals: “I’ll never starve myself again.”

As well as working out daily, pals say she’s cut down on drinking and fatty takeaways.

A source says: “Nat says she has made a pact with herself to stay fit this time. It’s not a diet or anything drastic – she knows that’s the way to fall off the wagon. She feels amazing.”

In December, the former EastEnders star revealed she’d lost 1st 2lbs in six weeks, shrinking to 9st 4lbs and going from a size 14 to a 10, with regular workouts and healthy eating.

Pals say she’s now just under 9st and is confident she’ll keep the weight off, after yo-yoing between a 6 and a 16, weighing 12st 7lbs at her heaviest.

Back in 2007, Natalie, who’s 5ft 4, dropped to 7st 12lbs for a fitness DVD, but later admitted she was “miserable” and had resorted to taking laxatives and not eating, before dramatically lapsing and regaining the weight.

She said last month: “After starving myself for the DVD, I just ate and ate. I devoured 10 packets of crisps in one sitting and I didn’t even feel guilty.”

The star, who’s mum to Eliza, two, also hit rock bottom with boyfriend Adam Cottrell in 2011, when he ended up in court after admitting assaulting her during a drunken row. They reunited last February after nine months apart and after he underwent treatment for alcohol addiction.

Now pals say Natalie’s never felt more in control since overhauling her lifestyle. She recently Tweeted: “Going to try my best 2 train & eat healthily for life now. When I’ve lost weight before, I’ve never had the determination.”

She now works out for an hour, six times a week, at the gym and with her personal trainer, Rob Horslen. Even on her rest day, she’ll make sure she’s still active by taking a long walk with Eliza.

Natalie, 29, does fat-burning high-intensity cardio, weights and treadmill running, as well as toning exercises and Davina McCall’s fitness DVDs at home.

Sources say she avoided carbs completely at the beginning and stuck to 1,200 calories a day for around six weeks, before recently reintroducing carbs, eating up to 2,000 calories a day and allowing herself one treat of a chocolate bar.

She swapped regular milk for soya milk and, after declaring in December, “I don’t want to drink to get drunk any more,” pals say she barely touches alcohol.

She recently Tweeted: “Cannot wait to see my ads and chill out to @BBC6Music with small glass of red. #chateauxpap […] I may not even open it once I’m home! #seehowifeel #dontdrinkforsakeofitanymore”

A pal adds: “Rob has taught her to take control of her diet by cooking from scratch, so she knows exactly what she’s eating.

“It’s an effort for Nat to stay slim. She has to be 100 per cent focused and, if she’s really hungry, she’ll make bad choices, so she also makes sure she keeps healthy snacks like carrots and houmous or fruit for when she’s out.

Takeaways are limited to every other week, not every Friday as they used to be. Now Adam will cook her a curry or Chinese and it’s much healthier.

“She rarely drinks at home to support Adam and, when she goes out, she just has a couple. She loves wine, but tends to go for vodka these days and avoids cocktails since Rob told her they were as sugary as Danish pastries. She says she’s in the best shape of her life and she wants to stay there.”

And friends say Natalie couldn’t be happier to be back on an even keel with Adam. She said in December that her new figure had had an effect on her confidence, saying in an interview: “I do feel sexier now. Adam asks me why I’m suddenly walking around the house in skimpy underwear!”

A source adds: “Natalie says feeling good about herself makes everything else better, including her sex life, and jokes that they’re ‘at it like rabbits’ these days!

“Adam’s been a huge support and loves her body, although he doesn’t want her to lose any more weight because he likes her curves. She loves her slim legs and how toned she is and also that her face is more defined.

“She says being happy in herself and her body go hand in hand. She and Adam row like any couple, but she says they love each other. He’s really proud of her. It’s a lifestyle change – she’s banned the word diet. She doesn’t want to feel self-conscious in a bikini again and vows never to go back to yo-yo dieting.”

Natalie said in December: “My ultimate goal was to look curvy, toned and fit […] It’s been challenging but worth it.”