The 29-year-old, who famously dropped from a size 20 to a size 8 in a year, stunned in a plunging, floor-length coral number on the red carpet in London last night.
Speaking about how she has kept her body in shape, Josie revealed that she is on the 80/ 20 rule, which is similar to the 5:2 diet.
Having dropped from 16 stone 10 lbs, to 10 stone 2 lbs, the reality star from Bristol now feels she's at a happy weight.
Forget fad diets,' Josie told MailOnline.
'Nine out of 10 people on a fad diet will always end up putting weight on again. The healthiest way to lose weight is to eat natural and clean foods.
THE '30 SECOND SLIM' DIET FOLLOWED BY JOSIE GIBSON- THE MEAL PLAN
'Some people think it’s all about the amount of calories you eat vs the amount of exercise you do, but it's so much more than that. Some of my friends eat the same things I once did, but will never put the weight on.
'It boils down to your genetics, what you eat, your environment, how you shop for food, how you feel about yourself, your addictions and all sorts of factors.'