"Look at my lil sis@rosiepierri she been taking gr8 care of herself w/help from@PhatBurn Team!!" she tweeted.
Kathy included a before and after picture set showing a way slimmed-down version of Rosie on the right.
The Phatburn diet provides you with food and exercise trainers, so they take all the guesswork out for you. After 60 days of balanced nutritional meals and an hour of exercise five days a week, it's no wonder Rosie dropped so many pounds.
And with all that added confidence from Arizona, Rosie’s set to be a new woman.
Are you surprised by Rosie's dramatic weight loss? Share your thoughts in the comments below!