5:2 Diet: How Does It Work?

So you’re interested in following a diet to lose weight. Great! We have all the information you need to start, with no fad or gimmick attached. Our goal is to provide simple, authoritative guidance on how to craft a diet that will work for you.

What is the 5:2 diet? Simply put, it’s a type of “eating plan” that relies on a schedule of either five very-low-calorie days (Wednesday – Saturday) or two weeks of high-calorie days (Monday – Friday), followed by two weeks of strict-low-calorie days (Sunday – Tuesday).

Let’s take a closer look at how this diet will work.

The Basics Of The Diet

The first thing you should do is to figure out how much you need to shed. There are several tools online that can help you determine how many calories you need to consume each day to lose weight. For example, this online calorie counter will estimate the number of calories you need to maintain your weight based on your gender, age, and activity level. Simply enter the information necessary for the tool to calculate the calories you need, and you’ll have a good starting point for your diet.

Once you know how many calories you need to lose, you can start looking for ways to cut back on your daily calorie intake. Cutting back on the carbohydrates in your diet will help reduce your calorie intake by about 10%. Eating plenty of vegetables and lean meats will also help, as will getting plenty of sleep and staying hydrated. And of course, you should never underestimate the power of a good workout!

What About The Food?

Okay, now that you have your daily calorie count, you can start thinking about the types of food that will help you reach your goal weight. There are several fad diets that promote eating a certain food group or nutrient-dense food, like tomatoes or avocados. While these types of foods may help you lose weight, they don’t offer much in the way of nutrition. It’s a food-compositional question: which food groups do you need to fill your diet with to lose weight?

When developing a diet to shed some weight, you should always opt for quality over quantity. That is, you should always opt for fresh fruit and vegetables over frozen ones or convenience meals. The same goes for meats—you’ll always have a choice of fresh, pre-cut steaks or chicken nuggets, rather than a package of pre-cooked meat (which will often be high in empty calories).

Now here’s the important part: you should always opt for healthier options when eating out. Even when ordering food straight from restaurants, you can ask for no sauce, extra grated cheese, or vegetable side orders – whatever makes the food healthier. You should also be mindful of the portion size when eating out, especially when restaurants sometimes put crazy amounts of food on your plate. The key to successful weight loss is to always opt for a healthier food choice whenever you have the opportunity.

How Does The 5:2 Diet Work?

The basic tenet of the 5:2 diet is to follow either a five-day diet cycle or a two-week diet cycle. For day one of each cycle, you will consume roughly two-thirds of the calories you need for the day. On day two, you will consume one-third of the calories you need. On day three, you will consume one-fifth of the calories you need. On day four, you will consume one-eighth of the calories you need. And on day five, you will consume the final quarter of the calories you need. This will repeat until your weight stays the same or starts to decline. 

What happens on the high-calorie days? Those are the days when you will consume the remaining one-third of the calories you need for the day. You will not lose any weight on high-calorie days, but you will improve your health.

Here’s how a five-day cycle of the 5:2 diet works:

  • Monday: High-calorie day
  • Tuesday: High-calorie day
  • Wednesday: Very-low-calorie day
  • Thursday: High-calorie day
  • Friday: Very-low-calorie day
  • Saturday: High-calorie day

And here’s how a two-week cycle of the 5:2 diet works:

  • Monday: High-calorie day
  • Tuesday: High-calorie day
  • Wednesday: High-calorie day
  • Thursday: High-calorie day
  • Friday: High-calorie day
  • Saturday: Low-calorie day
  • Sunday: Very-low-calorie day
  • Monday: Low-calorie day
  • Tuesday: Low-calorie day
  • Wednesday: Low-calorie day
  • Thursday: Low-calorie day
  • Friday: Low-calorie day
  • Saturday: Very-low-calorie day
  • Sunday: Very-low-calorie day

Both cycles begin with a high-calorie day and end with a low-calorie day. The distinction is that on the high-calorie days, you will eat more food and spend more time in the kitchen, while the low-calorie days will consist of more resting and sleeping. This is a major point in favor of the 5:2 diet: it doesn’t require you to go on a crash diet, which is often harmful and short-lived. You simply follow the diet and exercise plan as prescribed, and you will start losing weight steadily. 

Now is a good time to mention that neither of these diet plans is “calorie counting” or “macros” compliant. That is, you will not be able to simply subtract calories from foods you eat and add the calories you burn to keep your weight the same. To stay in compliance with the diet, you will have to use an online calorie counter like My Fitness Pal or Lose It.

The Pros And Cons Of The Diet

One of the things that make the 5:2 diet so appealing is its simplicity. There are no complicated formulas to follow or special food to eat. Instead, you simply follow the schedule of low-calorie days and high-calorie days as instructed, and you will begin losing weight.

The 5:2 diet also has a very clear explanation for what is happening. On the low-calorie days, your body will enter a state of ketosis. This is a well-known metabolic process where your body breaks down fats into fuel rather than stores them, like most diets do. The result is that your body will begin using up stored fats, causing you to lose weight effectively even if you consume the same number of calories as you did before. The low-calorie days also make it easier to monitor your progress. Instead of having to guess at how much you’ve eaten based on how you feel, your body fat, or the amount of food left on your plate, you will be able to follow the daily patterns of ketosis and be more precise about how much you’ve eaten.

On the other hand, the 5:2 diet only provides the body with certain nutrients. Now is not the time to be deficient in any nutrients, so you should make sure you consume the right amount of protein, vitamins, and minerals on a daily basis.

Another con for the 5:2 diet is that some people may find it difficult to adhere to the strict low-calorie days. If you’re an active person who enjoys eating lots of food, this diet may be difficult to follow. Also, if you have a tendency to binge eat, this diet may serve as a trigger for your binge eating episodes. In these cases, the patient may need to modify the diet to fit their lifestyle, such as incorporating more high-calorie days or longer periods of low-calorie days.

The Bottom Line

Adherents to the 5:2 diet report significant weight loss and improved quality of life. This diet is a great choice for people who want to lose weight and don’t want to go on a crash diet. As long as you keep to the schedule and exercise regularly, you will be on your way to achieving your goals.