The 16:8 diet

Basically, no food for 16 hours, then all you can eat for the remaining eight. With the 16:8 diet you can drink unsweetened beverages such as tea, coffee or water in the first 16 hours but, just to stress the point, no food. Hugh Jackman used this while preparing for Wolverine.

“The 16:8 may promote weight loss and improved blood sugar control,” says consultant pharmacist James O’Loan of online UK pharmacy Doctor 4 U. “And due to this 16-hour beverage window, you’re also less likely to feel hungry compared with other fasting diets.”

However, because you can eat any type of food and as many calories as you like in those eight hours, it can be hard to follow a balanced, nutritious diet. Binge eating can get all too easy, as well.

The 5:2 diet

The most popular intermittent fasting protocol. Twice a week you cut your daily intake to just 500 calories, while eating normally for the remaining five days.

“The 5:2 diet is a simple way to reduce calories,” says O’Loan. “It may help with weight loss, improve cognitive function, control cholesterol and blood sugar levels.”

It’s the most flexible of all the options but because you can spread your intake of those 500 calories across the day you might not enjoy the full benefits of giving your digestive system a complete rest. “It could even leave you feeling more hungry,” adds O’Loan. “And it can cause disruption to sleep, irritation, dehydration and bad breath.”

Eat-stop-eat

The eat-stop-eat diet follows a similar pattern as the 5:2 diet, where you eat normally for five days and fast for two, but it requires you to completely fast for 24 hours once or twice a week.

“This is less complicated than the other fasting diets, which can make it a more manageable option for many to follow,” says O’Loan. However, he warns, it can take some getting used to. “In the first few weeks you can become irritable and experience headaches and mood changes.”