The 22-year-old 'Hot Right Now' hitmaker recently stayed at Viva Mayr clinic to get in perfect shape for the upcoming season, reported Daily Mirror.
"It's the most opulent weight-loss and detox clinic in the world, and pretty hardcore. Rita wants to get in perfect shape for the summer and her forthcoming promo appearances.
"Following a detailed examination and fitness test, she was given a rigid diet-and-exercise regime, with a few deep-tissue massages thrown in for good measure," said a source.
"The food is mainly boiled potatoes and broths, and guests are taught to savour their food by chewing it a minimum of 30 times per mouthful. The programme set for Rita was designed to be a blueprint for the rest of her life, helping her keep on the straight and narrow," the source added.