The 24-year-old went from a size 16 to a size eight for her record-breaking fitness DVD – but new pictures had some thinking she'd already gained weight again.
But Geordie Shore star Charlotte insists that's not the case. She said: "I haven't put on weight. I was a bit puffy after a 24-hour flight [to Australia], plus I was due on my period.
"It's very bad for people to say that I've changed when I haven't. Those are the kind of stories that could lead to someone getting an eating disorder.
"It's very sad someone would even suggest I'm fat. I't pathetic."
While she's been on tour in Australia, Charlotte hasn't been shy with the bikini selfies. Speaking to Star magazine, she continued: "If I was worried, I wouldn't be sitting around the pool in my bikini, like I am right now.
"People haven't seen me in real life. That's not how I look."
While Charlotte is happy with her new body, she insisted she will not become obsessed with keeping fit.
She said: "I'm not the kind of person who'd go down the silly route of becoming too obsessed, but I can see why famous people get insecure, because people judge you all the time."