100 recipes, 4 weeks of sample menus and packed with tips on how to integrate the 5:2 diet into your lifestyle. The growing popularity of the 5:2 intermittent fasting diet is not doubted. Increasing numbers of advocates embrace its flexibility: you choose which two days of the week are your 'fast' days; you lose weight and the diet is sustainable and healthy over the long-term, unlike many other diets.