The outspoken TV personality gained over 3 stone just so she could lose it in an effort to prove that there are ‘no excuses’ to be overweight.
Katie, 39, ate up to 6,000 calories a day in an effort to take her weight from 8st 12lbs to over 11st.
At her heaviest, the former Apprentice star stopped having sex with her husband as she felt unattractive.
She told The Sun: “I am normally the first one to get my kit off — and don’t give a damn who sees me naked. However, after I put on my first stone I stopped having sex with my husband.
“As a fat bird, I stuck to pyjamas and getting naked in the dark.
“When you look gross, you feel gross. When you feel gross you don’t want anyone else touching bits of you that wobble.”
Speaking to The Sun on her weight gain, she said: “Being fat is hard work. You can’t be fat and happy.”
She wrote on Twitter last night: “Yes darlings, I have a face like a melted wheelie bin etc, but sweet cheeks - I don't have to look at it. You choose to.
"I see you all down there with your excuses, but a third of the planet is obese. The fist step to slim is NO EXCUSES. Own your problem."
Will you be watching Katie’s documentary on Friday?