That is on the NHS website? This involves changing your eating patterns in 12 weeks by sticking to 1400 calories a day, you print off a weekly sheet where you can record daily calories, exercise, five a days and weekly start and end weight. It looks pretty sensible and achievable as the aim is to change eating patterns in the long term to achieve weight loss. I am going to start the 12 week challenge tomorrow if anyone wants to join me?