How Bad Is Going Off Your Diet?

Last week we spoke about the effects of taking a break from exercise. While some of the benefits you gain when exercising reverse over the course of several weeks, including muscle size, strength, aerobic capacity, and metabolic benefits, they can all be quickly regained once you resume exercising again.

This week let’s shift our focus to diet.

How detrimental is it to take a break from our diet? How bad is deviating for one meal, one day, several days, or even several weeks?

No matter what your goal is for eating a specific way, whether it’s fat loss, muscle gain, mental health, or just to maintain the level of health and performance you currently have, the way you eat cannot be the same 356 days a year.

There are going to be vacations, work travel, social engagements, stress, boredom, birthdays, and holidays.

There are going to be days where you eat a lot, have a few drinks, eat cake and ice cream, eat out at a restaurant, and don’t have access to the food you normally would.

This is life in the modern world, there are going to be days that come up and cause you to eat in a way that is not perfectly aligned with your goals

When these events happen…and they will happen…how detrimental are they for our goals?

If you have been poking around on the internet you have probably come across people talking about cheat days, refeeds, and diet breaks. All of these terms refer to planned meals, days, or even several weeks, where someone intentionally raises their calories. In fact there is actually a lot of research around the effects of coming out of a diet for a period of time and how that impacts various outcomes. We can use this research to frame our discussion around how detrimental breaks in our diet are.

But before we take a look at some of the science around taking a break from your diet, let me take issue with one of these phrases…cheat meals.

The word cheat has a negative connotation and I think the mental impact of using the word cheat is not very beneficial for most people.

One of the biggest problems I see when it comes to people trying to achieve any goal is beating themselves up when they deviate from their plan. As we will see in this post, that negative self talk is probably not warranted. However even knowing that the deviation isn’t detrimental by using the word cheat you are framing things in the negative. This negative framing may cause you to have a more extreme reaction to the deviation. For example if you say you cheated on your diet you will be more likely to be more restrictive the day after, which as we will see, can result in “cheating” more in the future.

So let’s stick to the terms refeeds and diet breaks in our language around diet.

With that out of the way we can move on.

Food is more than fuel and energy.

Food is hedonic, it brings pleasure.

Food is also social and emotional.

When we restrict food, you are not only restricting energy in an effort to lose fat, you are restricting pleasure, you are restricting social engagements, you are restricting the emotional attachments that food comes with.

Similarly, if you are putting yourself in an energy surplus for performance or muscle gain, again you are taking away the pleasure and emotional benefits of food. In some cases people may also be sacrificing nutrient density in an effort to eat more food (nutrient dense food will almost always be more satiating). Eating purely becomes about eating as much as you can handle.

That might sound great, but let me tell you from experience that when you are eating in a caloric surplus using whole foods the enjoyment quickly diminishes as you plan how much food you can fit in during a day.

Therefore I think the most important benefit from taking a break from your diet from time to time, is MENTAL!

It allows you to break free of the grind of the way you are eating, stop thinking about eating purely as it relates to the goal you are trying to achieve.

You can eat the cookies on Christmas that Grandma made because it’s something you have done since you were a kid and enjoy the memories and connection of doing that without feeling guilty or worrying about how it impacts your body composition

You can go out with your significant other and celebrate with a couple drinks if you want and just enjoy the connection you have with them.

You can eat the cake that your kids made for you for your birthday without guilt.

You can stop stressing about eating 6 times a day in order to get in enough food.

These are mental health wins!

Maybe they don’t serve your goals in the short term, but imagine if you could not enjoy these parts of life. Is that a life worth living?

In my opinion, removing the mental and emotional parts of food contributes to people eventually giving up on their diet and returning to a way of eating that no longer serves their goals.

OK, outside of the mental benefits of taking a break from your diet, can a refeed or diet break still allow you to reach your goals as opposed to sticking to a diet consistently?

First let’s put a more rigid definition around what we mean by a refeed and a diet break.

A refeed is generally defined as 1-3 days of eating at caloric maintenance or even in a surplus.

A diet break is generally defined as 1-2 weeks of eating at maintenance calories.

Essentially a refeed is a short term break from your diet done more frequently, likely on a weekly basis.

A diet break is a long term break from your diet but done infrequently.

A common refeed pattern would be to stick to a diet Monday through Friday and then be a bit more relaxed on Saturday and Sunday when you have more social engagements and want to be a bit more free with your diet.

Does eating like this work if your goal is to lose fat?

A study done on 58 resistance trained males and females had half the group maintain a 25% caloric deficit 7 days a week. The other half of the group (the refeed group) maintained a 35% caloric deficit for 5 days a week and then two days a week ate at caloric maintenance (no caloric deficit). (Intermittent Energy Restriction Attenuates the Loss of Fat Free Mass in Resistance Trained Individuals. A Randomized Controlled Trial, 2020)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7739314/

Participants followed these two eating patterns for 7 weeks and then took a look at the change in muscle and fat in the two groups.

As you can see from these graphs the refeed group lost a bit more fat and also was able to better maintain muscle over the group that maintained the same caloric deficit throughout.

The end result?

Better body composition for those in the refeed group!

Researchers theorized that the 2 days of maintenance calories could have reduced the muscle breakdown effects of being in an energy deficit. In addition, the 2 days of maintenance calories could have provided participants with more energy which resulted in more movement and better workouts. So despite the 2 days of eating at maintenance the additional movement and harder workouts could result in a bigger net caloric deficit and also provide more stimulus to grow muscle.

I think it’s important to note that this is a very calculated refeed. Saturdays and Sundays were not all out eat whatever you want occasions. They just raised their intake to what their caloric maintenance is. I see all too many people try to implement this approach and go into their refeed days with no oversight into how they are eating and go WAY over their caloric maintenance. This can easily outdo a week long caloric deficit and actually cause you to gain weight.

So please don’t mistake refeed days as a free for all when it comes to eating.

You still need to be mindful of your diet, in fact you are still eating the same foods you normally would, just adding a tad bit more back in those 2 refeed days.

Layne Norton has a great graphic from his book Fat Loss Forever that illustrates this point nicely.

https://twitter.com/BioLayne/status/1336048017057705985

In his graphic he uses Friday and Saturday as the days where people overeat, but the exact days do not matter, 2 days of eating everything and everything in sight is more than likely going to at least put you at maintenance for the entire week and more likely put you in a caloric surplus.

Refeeds still need to be regimented.

Now let’s talk about diet breaks. Could taking 1-2 weeks to eat at maintenance calories be detrimental to reaching your long term fat loss goal?

A study done on 51 men provides some insights. In this study half of the participants continuously dieted for 16 weeks straight. The other half of participants dieted for 2 weeks and then took a diet break eating at maintenance for 2 weeks and then went back on their diet. In total the diet break group took 30 weeks to accumulate 16 weeks of dieting. (Intermittent Energy Restriction Improves Weight Loss Efficiency in Obese Men: The MATADOR Study, 2017)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803575

What did researchers find in terms of fat and muscle mass changes?

Here are the overall weight loss changes between the two groups.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803575

As you can see the diet break group (the solid black line) lost more weight than the continuous diet group.

When we look at where the weight loss came from (fat or muscle) it appears most of the weight loss came from fat in both groups, but the diet break group lost more fat than the continuous diet group.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803575

You might also note that in this study the diet break group lost a little bit more muscle than the continuous group, however this study did not control for exercise (which is important for muscle mass maintenance) and the difference between the two groups was not significant, so that could just be “noise”.

One other interesting figure from the study was the amount of weight lost over the course of 30 weeks in the diet break group. Notice while on their 2 week diet break they lost very little to no weight, this is expected as they were eating at maintenance.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803575

If you were to implement this diet break strategy it might make you feel uncomfortable. You might think you are not making progress fast enough, or even reversing progress you have already made, especially when you have weeks where the scale goes up. The key with this approach is to stay the course, you should not be seeing a ton of weight loss on the diet break weeks and any weight gain is likely going to be water or just the fact you have more food in your stomach.

I would also like to mention that just like with the refeed approach, the diet break approach needs to be regimented. You need to be eating your maintenance calories, it is not a free for all!

I also think it’s important to consider some of the side effects of continuous caloric restriction and the benefits of coming out of those restrictions for achieving your long term goals.

Caloric restriction will also result in a decrease of micronutrients coming in via your diet. Long term this MAY result in deficiencies. Breaks in your restriction gives you an opportunity to consume more nutrients and perhaps avoid deficiencies.

In addition, caloric restriction can come with negative impacts on sleep. Sleep is a cornerstone of a healthy lifestyle and if your sleep is suffering due to the lack of calories, and a break in your diet helps, it’s certainly worth injecting these breaks.

Prolonged caloric deficits can also slow down your metabolism. The slowing of your metabolism is something people on the internet use to sell products, programs, and generate a lot of fear, but in reality it is a natural side effect of being in a caloric deficit. It is completely reversible and practices like refeeds and diet breaks can help mitigate the slowing of your metabolism.

Finally we have the stress of continuous dieting. The mental toll of sticking to a diet can be hard, and adding that to an already stressful life is not good for your health. A break in the diet can help alleviate that stress and could help your overall stress load.

On the opposite end of the spectrum is overfeeding. Unfortunately, I could not find research on the benefits of diet breaks in the context of overfeeding and it is not surprising given most of the world is not intentionally overfeeding and instead needs to be in a caloric deficit.

However, I do think there are benefits to occasionally dropping calories back down to maintenance if you have been trying to live in a caloric surplus for a long period of time.

The first thing that comes to mind is digestion.

Your gut is working hard to digest all that food, especially if you are in a surplus eating whole foods. It takes a lot to break that down. It’s also likely that your gut is working through most of the day to do it. Taking a break and dropping calories down to maintenance or even being in a caloric deficit for a period of time will help give your gut a break. Let it recover. Like any physiological function in the body, continuously stressing something will result in dysfunction, our digestive system is no different.

The second benefit to coming out of a surplus and eating less food for a period of time could be allowing your body to resensitize to the food you are eating. A good example of why this is important can be seen when we look at insulin sensitivity. A continuous surplus of energy can result in your body no longer responding to insulin. This is one of the main drivers of type 2 diabetes. We know that for some people when they dial back the energy they are taking in it can help restore insulin sensitivity resulting in improved insulin sensitivity. It follows then that other processes in our body can also become desensitized due to the amount of food someone is eating.

Also just like a prolonged caloric deficit can negatively impact sleep and elevate stress levels the same could be true for a prolonged caloric surplus. Having to expand your eating window later in order to fit in all the calories means you are eating close to your bed time and will likely disrupt your sleep. Then there is the stress of constantly making sure you have all the food you need to meet your caloric demands. Prepping that food and always having access to it can be stressful.

That all said, if you are someone who is trying to gain muscle and has been in a caloric surplus I think a diet break strategy, taking a break to eat at maintenance, or a “defeed” strategy where you spend 1-2 days eating at maintenance or in a slight deficit can be just as beneficial as they are for someone who is in a caloric deficit.

By all accounts I think taking a break from your diet is going to be beneficial to you whether you are trying to lose fat or gain muscle. In my opinion, even if it didn’t result in better or the same results, I think the mental benefits alone are reason enough to take a break. I also think that these breaks don’t need to be so regimented or planned out if you don’t want them to be. However you do need to be conscious of how much you are eating when you do take these breaks. Drastically overdoing the break is going to be a net negative at the end of the day.

I will be discussing how to practically inject breaks into your diet and exercise in part 3 of this blog post series. To be the first to know when part 3 is posted be sure to sign up for my newsletter using the form below and I will email you as soon as it is available

References

Intermittent Energy Restriction Attenuates the Loss of Fat Free Mass in Resistance Trained Individuals. A Randomized Controlled Trial. (2020, March 8). NCBI. Retrieved April 19, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7739314/

Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study. (2017, September 19). NCBI. Retrieved April 19, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803575