Josie is wearing a rather fetching (not!) metallic red all-in-one in the picture, similar to those worn by Big Brother contestants during their notorious electric shock tasks.
We imagine the snap was taken soon after she won the 2010 series of BB, as Josie has now slimmed down dramatically.
At her heaviest, Josie weighed 18st and wore a dress size 24, but she swapped fatty foods for veg and began working out.
The reality star, who released her own fitness DVD Josie Gibson's 21 Day Fat Burn, now weighs a healthy 10st and wears a size 10-12.
Alongside the throwback picture, which Josie posted on Twitter, she commented: "Lol I just found this."
Speaking to Reveal last week, Josie admitted she received death threats and felt suicidal when she was big.
She added: "You've got to like yourself to lose weight. If you don't, you're not going to look after yourself and put good food in your body."