The 5:2 diet, or fast diet, is a diet which involves calorie restriction for two non-consecutive days a week and unconstrained eating the other five days, which originated and became popular in the UK, and spread in Europe and to the USA.
The 5:2 diet is a diet. Fast diet, is a diet. This diet involves calorie restriction for two non-consecutive days a week. This diet unconstrained eating the other five days. This diet became popular in the UK. This diet spread in Europe and to the USA. The other five days originated.