The 5:2 Diet, also referred to as The Fast Diet, is a type of intermittent fasting- an eating pattern that involves regular fasting. The 5:2 Diet is simple enough; for 2 non-consecutive days a week, no more than 500 calories a day (or 600 calories for a man) should be consumed, with normal eating during the rest of the week (the remaining 5 days).
The theory is that by significantly reducing calories on fasting days will result in a weekly calorie deficit enough to trigger weight loss. The 5:2 Diet is more an eating pattern than a food diet in that, technically, there are no rules or directions regarding the types of foods that may or may not be eaten.
For many people, The 5:2 Diet is a lot more straightforward, easier to follow and adhere to than more conventional calorie-restriction diets.
The 5:2 Diet appears to be an effective way to control weight for a number of reasons. In addition to it aiding the consumption of fewer calories, it also promotes fat burning hormones and an increase in metabolic rate.
Diets involving continuous calorie restriction over a long period of time can result in a lower metabolic rate (the rate at which our bodies burns calories) in order to save energy and protect against starvation. When calories are restricted for two days per week only, the body feels less under threat and is less inclined to burn calories.
The 5:2 Diet has the flexibility that includes the freedom on whichever 2 days of the week for fasting (so long as there is at least 1 non-fasting day in between). There is no specified way to eat on a fast day; some participants will prefer to eat 3 small meals during the day; others may choose to eat 2 slightly bigger meals. The time of the day that meals are eaten is entirely optional. Since calorie intake is limited, foods must be chosen wisely; it is best to choose high-fibre and high-protein foods such as vegetables, fruits, legumes, fish, and lean meats- these foods are satiating as well as being relatively low in calories.
With regard to non-fasting days, it is important to emphasise that eating ‘normally’ does not mean eating without limit; it means sticking to the recommended daily calorie intake (2,000 for women and 2,400 for men).
The 5:2 Diet is suitable for healthy adults looking to lose weight and enhance their health. The diet may not be suitable for highly active people; for some it may be easier to fluctuate between restriction and non-restriction to produce better results.