She slimmed down to a size 8 just five months after the birth of her fifth chid for her dream wedding to George Kay in September, flaunting her bikini body on honeymoon in Barbados.
But on our exclusive shoot, Kerry admits after indulging over the party season she has put on a stone and has gone up to a size 10-12.
Kerry reveals: "I really indulged in December. My mum and George's parents were staying and it was a full household. We had buffets every day and I just ate and ate. We had lots of roast dinners and turkey sandwiches, plus crisps and chocolate, then lots of Cava and Prosecco… plus Jäger shots!"
But after starting a diet with Closer, Kerry – who's seen her weight yo-yo between a size 6 and a 16 over the years – insists she is determined to snap back to a size 8 before going on a world tour with Atomic Kitten in May.
Determined to shed the pounds Kerry says: "I've lost weight before and I am always confident I can do it again. I put on weight quickly but I drop it fast too. For me, it's not about being skinny. George prefers me at this size so if I really wanted to stay this way, I could. But I hate feeling a bit unhealthy."
Read the full story in this week’s Closer – out now