Michael Mosley has said that it is possible to lose weight eating 800 calories on FDs but what you need to bear in mind is that if you eat more calories on FDs your weight loss will slow down and 5:2 isn’t exactly a quick weight loss method.

It’s all about creating a calorie deficit and it takes a deficit of around 3500 calories to lose 1lb which is the average weight loss in a week for women doing 5:2 eating 500 calories on fast days.