The 5:2 diet sees you eat normally for five days and fast for two days and is believed to be a simple way of losing weight. Celebrity supporters include Phillip Schofield and Hugh Fearnley Whittingstall.
Fans claim it can improve lifespan, brain function and protect against conditions such as dementia and Alzheimer’s.
Pros: People only need to stick to a diet regime two days a week and are more likely to persevere and successfully lose weight.
Cons: On non-diet days you cannot eat more than usual and skipping meals can make you dizzy, irritable, give you headaches and make it hard to concentrate.
The Dukan diet is a low-carbohydrate and high-protein diet and there is no limit to how much you can eat providing you stick to the rules of the plan which is over four phases.
The first phase limits you to a strict lean protein diet, including food such as chicken, turkey, eggs, fish and fat-free dairy. This is for an average of five days to achieve quick weight loss. Carbohydrates and vegetables are banned in thisnext three phases of the plan see the gradual introduction of some fruit, veg and carbohydrate and eventually all foods. The aim is gradual weight loss of up to 2lb a week.