What Is The 5:2 Diet?

The 5:2 diet originated in the United Kingdom in the 2010s and was popularized by Micheal Mosley, a medical journalist. As a form of intermittent fasting, the diet involves restricting calories for two days of the week. Followers of the plan can eat what they like for the remaining five days, and there is no need to restrict or monitor calories on these days. The plan allows an unlimited choice of foods and drinks on all days of the plan, so patients are in complete control of what they eat and can choose foods they enjoy. Since the plan only requires calorie restriction for two days, some individuals find the 5:2 diet is easier to maintain than traditional diets that require daily calorie restriction. Of course, patients should always check with their doctor before beginning any type of diet or fasting program to ensure they can complete the program safely.

The guide below discusses the basics of the 5:2 diet and provides information on the benefits and risks of this eating plan.

Intermittent Fasting Basics


As the name suggests, intermittent fasting involves fasting for a short period. Some of the most popular intermittent fasting approaches involve simply confining eating times to a set number of hours per day. For example, patients might choose to fast for sixteen hours of the day and consume all of their food within an eight-hour timeframe. This method is often used by individuals who are new to intermittent fasting. As individuals become more comfortable with this eating method, they may decide to have a smaller eating window; common approaches ask the patient to consume all of their meals within six hours while fasting for eighteen hours, and some patients choose to allow themselves a four-hour eating window with a twenty-hour fast. During the eating window, the patient eats all of their meals as normal; there is no requirement to count calories or to change the patient's regular diet in any way. Rather, the patient simply eats as they normally would, and the meals are consumed within a set number of hours. To make the fasting hours easier, many patients start by fasting overnight and eating breakfast a few hours later in the day than they otherwise might. They can then restrict their eating window more after adjusting to this. It is typically advised that no food is consumed during the fasting periods, though patients are allowed to drink unlimited water, herbal tea, and other calorie-free beverages. An advanced variation of intermittent fasting involves a total fast (with no food) for twenty-four hours on two or three days of the week, and the patient follows their normal eating pattern on the remaining days.

Get familiar with how the 5:2 diet plays into this next.

Emily Fowler