It comes as the former Coronation Street cast member was forced to pull out of the show after suffering an injury – and she's now begging for a "pie".
In a photo of the 36-year-old wearing a long leopard print skirt, she can be seen tugging at the waist and pulling it away, showing inches of extra material.
Tagging Strictly in the post, Catherine wrote: "It's official, I need a pie. Lost my junk."
Catherine is no stranger to weight loss, having dropped six stone 10 years ago and completely overhauling her image.
Despite her new bout of weight loss – and injury – the actress is keeping active and still making time for her gym sessions.
Taking to Instagram, Catherine told her 599,000 followers that she was at the gym but "a bit nervous".
She explained: "There is not much I can do with my injury so I'll be doing lots of upper body and core work, some rehabilitation exercises.
"Barrel of laughs. I mean, we are week one and I'm already ready to ram my head into a brick wall with frustration.
"But everything for a reason, it's a healing process, I'll let you know how I get on."
Last month, Catherine confessed she was "absolutely heartbroken" to have to pull out of the Strictly live tour.
She said: "I've had to finish my time on the Strictly tour earlier than expected. Unfortunately i've sustained an injury which means I'll be unable to dance for a while.
"My experience of the tour has been a complete joy. Each audience has been so full of love for Strictly. My fellow dancers are all phenomenal and I'm so grateful to have experienced such a magical show.
"Devastated is an understatement. Wishing my Strictly family the best time with the rest of the tour."
Catherine had been performing on the tour with her pro partner Johannes Radebe.