Writing in her Sun column on Friday, Katie told readers she has gone from underweight to overweight, more than doubling the amount of fat on her body - and it's all for a project she is working on.
Famous for her fat-shaming, Katie is apparently eating over 6,000 calories a day for a new documentary, where she will prove the only thing making us bigger is eating too much and moving too little.
As part of the programme she will also show how she loses the weight with ease just by being sensible again.
'So far I have eaten 13 ready meals a day. Chocolate bars, fizzy drinks, curries, chips, cake, cream - I've scoffed it all.'
According to Katie, she now has more 'rolls and folds than I know what to do with' and is the biggest she has ever been.
'Instead of facing upto our problems, we super-size the world around us to fit,' Katie writes.
'Bigger models in shop windows, plus -sized uniforms for kids, wider seats at the movies. Anything but accept the cold, hard fact that in most cases we are big, fat and lazy because we eat too much and don't move enough.'
What do you think, do you agree with Katie?