Kerry Katona four days after debuting her £15,000 new body

After spending £15,000 on regaining her pre-pregnancy figure Kerry Katona might have been expected to hold back as she headed off on holiday.

But just four days after revealing her slimline shape there appears to be a whole lot more of the mother-of-four.

Her stomach bulged out of her pink velour tracksuit as she went shopping in Marbella yesterday

Toned to tummy in four days: Kerry Katona's stomach looks bigger, left, as she enjoys her Spanish holiday

The former Atomic Kitten singer, 28, underwent a breast reduction operation, liposuction and removal of stretch marks at the St John and St Elizabeth Hospital in North London in August.

Just this week Kerry revealed her joy over the successful surgery, as she flew out of Manchester Airport for a sunshine break with her husband Mark Croft.

On Tuesday she dressed in tight-fitting jeans and a fitted top to show off her body. But after four days of enjoying herself Kerry's figure appeared to be showing the strain.

Overindulging? Kerry climbs out of her cab looking a bit bloated yesterday

Kerry decided to undergo surgery after growing unhappy with her look following the birth of her fourth child, Max, in April.

Rather than lose weight through dieting and exercise, Kerry chose the surgical option after complaining of the toll childbirth had taken on her.

After being made bankrupt by the High Court just a week before her operation, the procedures were paid for by MTV, the producers of her reality show Whole Again.

Kerry's operation will be screened on the programme on MTV One later this month.

Before the operation: Kerry Katona grabs her FF boobs for the last time before undergoing breast reduction surgery

Writing in her column in this week's OK! magazine, an ecstatic Kerry said: 'Yesterday I went shopping for the first time but all the bras looked stupid on my new boobs - I actually look better without a bra.

'I bought a lot of gorgeous size 10 dresses, how cool is that? I'm loving having a waist and a figure after being pregnant for about three years.'

Kerry's operation has reduced her cup size from a 34GG to a 34DD.

'It's like I've got another bird': Husband Mark is delighted with Kerry's post-op figure but how long will it last

Husband Mark is equally pleased with Kerry's new figure: 'She's loads trimmer and she looks exactly like she did when I first started seeing her. I much prefer her like this.

'It's like I've got another bird in bed with me.'

The couple, who married in February 2007, have two children together, baby son Max, aged six months, and toddler Heidi, 19 months.

Kerry also has two daughters Molly, seven, and Lilly-Sue, five, from her previous marriage to Westlife singer Brian McFadden.