Can Diet Breaks Help in Weight Loss?

diet breaks

Quality weight loss is a long and slow process. While on a diet, time seems to flow more slowly, and will and patience are kept on the line so that they do not collapse.

However, is it possible that taking a break from all this not only does not hinder but even helps the end result?

No one likes to be on a weight loss diet. We all love and want the end result, but the process itself does not. Patience is also not one of the strengths of most people.

All this makes us want everything to end as quickly as possible and day after day, week after week, month after month, to count the remaining days until the cherished moment when everything will end.

There can be no question of stopping or interrupting. The sooner all this gets out of our heads, the better.

That’s why the typical scenario is like this – non-stop dieting, without interruption, without rest.

But isn’t there another approach that is both more effective and makes the whole process far less hateful and difficult?

What are diet breaks?

These are periods of time during which the person deliberately stops losing weight, and for this purpose, a calorie deficit turns into a calorie balance or even a slight excess of calories.

This concept may already be familiar to some readers as refeeds, but feeding days usually refer to shorter periods in calorie balance or a slight excess, especially 1 to 2 days, which most often belong to periodic fasting protocols. In the approach with interruptions in the diet, we are talking about a minimum of 7 days.

Perhaps one of the first experts to raise the issue of diet interruption was Lyle McDonald in his 2005 book “A Guide to Flexible Dieting.”

One of the scientific references, in which all the information and idea of ​​the book lies, is the scientific experiment of Wing and Jeffery in 2003.

Wing and Jeffery are experimenting to find out what would happen and how the results would change in people who are deliberately told to stop their diet earlier than the ultimate goal.

Because scientific data shows that most people give up and fail in the weight loss process 6 months after it starts, the experiment aims to see if an earlier break will have the same result.

To this end, one group of people were on a diet continuously for 14 weeks, a second group took a large break of 6 weeks in the middle of the 14 weeks, and a third group took three separate two-week breaks.

The results showed something very interesting and completely contrary to the expectations of the organizers of the experiment. Although weight loss stopped and even increased slightly during the diet break, at the end of the experiment, weight loss was identical in all groups.

It was as if some hidden mechanism in the groups interrupted them allowing them to catch up after the resumption of the calorie deficit.

Despite the curious results, however, it took nearly 15 years for Byrne and his team to publish an experiment with a similar methodology.

In the Byrne experiment, participants were divided into two groups. One group has been on a permanent calorie deficit for 16 weeks. The other group was again in a calorie deficit for 16 weeks, but every 2 weeks a calorie deficit makes a 2-week break (calorie balance).

Both groups followed the same 33% calorie restriction and consumed the same amounts of protein, carbohydrates, and fats. The study is very well controlled.

The results were again impressive. The group that took two-week breaks in calorie deficit managed to lose ~ 50% more total weight and body fat compared to the group that was non-stop on a diet, without a significant difference between the groups in weight loss (lean mass).

Six months after the end of the main part of the experiment (calorie deficit), additional measurements showed that the group which made breaks managed to keep 80-90% of the lost weight.

Thanks to most of the data available in the experiment of Byrne and team, this time the probable cause of these results is revealed.

Mechanisms of action

Those who have tried to lose weight and maintain a long-term calorie deficit know that the process is not as straightforward as we would like.

In short, during a calorie deficit, our body activates various mechanisms (hormonal, neurological, and others), which aim to slow down the weight loss process, and the goal is to be able to survive as long as possible in the absence of energy.

The available data at the moment suggest that dietary interruptions may counter these mechanisms of our body’s adaptation.

In the experiment of Byrne and team, for example, the resting energy expenditure (REE) of the intermittent group fell by about half less than the group that was non-stop in a calorie deficit (86 vs. 179 kcal/day).

What exactly are the mechanisms that lead to this lower decline in energy expenditure is not entirely clear, as these are currently the only available data on dietary interruptions.

There are some other experiments that explore this issue, but they use a different methodology and, unlike the experiment of Byrne and his team, are far less controlled.

To break or not to break?

Although, in theory, regular breaks in diet do not harm the end result and even have the potential to improve it, making a general recommendation for their use is not an easy task.

The reason is that although it does not harm the process, interrupting the diet prolongs its duration. If we take the example of the experiment of Byrne and his team, one group completed weight loss within 16 weeks and the other-32. Although in the latter case more total weight and fat were lost, we can hypothetically assume that if the first group prolongs its diet for as long as possible, it would achieve the same result.

In Wing and Jeffery’s experiment, some of the groups were again subjected to everything twice as long, and they didn’t even have an advantage in the end result.

Such a prolongation of the process may not be suitable for everyone. Professional athletes who have a fixed period to achieve a certain lower weight must pre-calculate the diet breaks as well.

An option for professional athletes is simply to dilute the protocol a bit. Although at this stage there are data only for 2-2 protocols (two-week breaks every two weeks of calorie deficit), many experts add 3-1 or 7-1 breaks.

On the other hand, it should not be forgotten that although a person eats more and is in a calorie balance during the break, maintaining strict control over nutrition remains a priority. Otherwise, there is a risk that the weight loss person will inadvertently overdo it and return to the starting position. Exercising this control continues to be mentally stressful.

However, for people with amateur goals, which are often purely health-oriented, diet breaks are highly recommended and in certain situations are essential for long-term success.

Some people have to lose 4-5 pounds, but others 40-50 and up. It takes years, not months, to lose so much weight at once. Maintaining a calorie deficit for such a long time can be extremely stressful and the risk of failure with such an approach is very high. This process can be far easier and healthier if the person losing weight takes a break every few weeks.


In recent years, more and more attention is paid to the concept of periodic weight loss and monitoring of calorie deficit.

Although in professional sports such a methodology requires more research before it is widely accepted, in amateur circles diet breaks are highly recommended.

More interesting research on the topic is yet to be published, and we from The Sized, as always, will follow them closely and share them with you.

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