Kerry Katona worries about her weight on ITV2's reality show The Big Reunion

While Atomic Kittens Natasha Hamilton, 30, and Liz McClarnon, 31, are thrilled to be back together, Kerry Katona‘s busy moaning about how fat she is!

A source close to Kerry, 32, reveals: ‘She’s devastated she’s the biggest in the group and is stressing out that when she’s on stage next to the other girls she looks even fatter.’

Performing beside petite size 8 Natasha and Liz and starring in new reality show The Big Reunion, which started last night, has brought size 10 Kerry‘s insecurities back to the surface.

‘She’s put on weight because she didn’t go to the gym once over Christmas,’ says our source.

‘She’s started to feel really self-conscious, so now she’s going to the gym every day for at least 90 minutes doing cardio to try and slim down.’

Read more about Kerry Katona and Atomic Kitten’s reunion in Now magazine dated 4 February 2013 – out now!   

 wk07-COVER-web.jpg

SEE PICTURES Kerry Katona: From pop princess to Dazed Of Warrington

SEE PICTURES Kerry Katona and Ashley Cole party with stars in London

SEE PICTURES Kerry Katona and Nicola McLean enjoy a girls’ night out in London