The Celebrity Big Brother contestant voiced her disapproval of the 'Toxic' singer's appearance at an official announcement of her X Factor USA judging role last week.
© WENN
© Rex Features / Startraks Photo/Rex Features
Writing in her OK column, Katona joked: "Britney Spears is The X Factor's new face - but she looks like she should be in The Only Way Is Essex.
"Normally judges look immaculate, but then she's had a tough few years. I'm not sure how she'll go down on TV. Her figure is great, but she just needs a new make-up artist and some acrylic nails - and that fake tan needs a good scrub."
However, Katona said that she is "rooting" for Spears and fellow new judge Demi Lovato after their past troubles.
© Rex Features / Greg Allen/Rex Features
"Demi has admitted to having problems and her and Britney Spears have both got lost in life as I have, so I'm rooting for them both," she wrote. "It's a good chance for them to prove themselves."
Katona recently revealed that she often gets called "the British version of Britney", but admitted: "I don't know why... at least I never shaved my head."
Spears reportedly landed $15m (£9.5m) to judge The X Factor USA.
