diet Breaks: are there any benefits?

Diet breaks are a strategy often used within the fitness industry during a fat loss phase. They can be useful for general population clients as well as more advanced athletes such as physique competitors and bodybuilders when working towards advanced levels of leanness. The usefulness of regular diet breaks, and how they are implemented, will depend on the situation and the goals an individual is looking to achieve.

As the name suggests, a diet break is a planned period, usually 1-2 weeks, within a fat loss phase where calories are increased to around maintenance. In this predetermined period, an individual intentionally moves out of a calorie deficit or negative energy balance.

Diet breaks are not necessary during a fat loss phase, and some people prefer to simply remain in a calorie deficit for the whole duration of their fat loss phase, preferring to get in and out of a calorie deficit as quickly as possible. With that said, we see diet breaks as a valuable strategy and find that implementing regular diet breaks can be beneficial to many people, can make a fat loss phase more enjoyable, and can also improve adherence, and therefore results.

psychological reasons for using diet breaks

One of the main benefits of diet breaks, and one of the most widely reported ones is psychological. Diet breaks give an individual a mental break from the monotony of dieting, and the importance of this can not be underestimated. Achieving good levels of leanness is a mental game as much as anything, and not being able to adhere to a calorie deficit for long enough is the reason why the majority of the population fails to get much below 15% body fat. Breaking a fat loss phase up with regular diet breaks can therefore be useful.

physiological reasons for using diet breaks

The physiological benefits of diet breaks include the reduction of fatigue that may have accumulated during a fat loss phase, which is more likely when we are consuming fewer calories and nutrients overall, especially when we are performing regular strength training working at a high enough intensity to preserve muscle mass.

what does the research say about diet breaks?

Some older studies seem to suggest that diet breaks may have some benefit to preserving resting metabolic rate and even showed body composition benefits such as greater fat loss and preservation of muscle mass in a fat loss phase. More recent studies have not found the same outcomes, however. A recent 2023 study following trained females performing regular resistance training in a 25% energy deficit, found no difference in fat loss, preservation of muscle mass, or preservation of metabolic rate.

One important point to understand is that this study was only performed for 8 weeks. Diet breaks may help preserve the metabolic rate in a fat loss diet over a longer period. It may be that the longer the energy restriction is in place, the greater the metabolic adaptation may be, although this is still unclear at this time.

What was great about this study was that calories and macros were equated as well as training volume between the group that had regular maintenance periods within a fat loss phase and those that did not. This is important because if calories are not equated, the group using regular diet breaks would be consuming a higher amount of calories on average over the same period, compared to the group who maintained a negative energy balance for the whole duration of the study.

One interesting finding was that the group that included regular diet breaks was less likely to break their diet by overeating or binging at some point during the fat loss phase. This suggests that periods of eating at maintenance calories give people a psychological break from dieting as mentioned previously and results in people feeling less deprived.

leaner individuals aiming to achieve advanced levels of leanness

Leaner individuals at around 12% body fat (18% for women) with the goal of achieving advanced levels of leanness will likely benefit more from diet breaks, and some individuals may need them. This is because they will be consuming fewer calories and nutrients, hunger levels will be higher, and stress hormones such as cortisol will be higher, especially after a prolonged period of dieting. Phycological stress will likely also be higher, and there is a greater likelihood of an individual breaking from their diet plan.

individuals who need to diet for an extended period

Individuals who have excessive amounts of body fat to lose will not experience many of the issues that leaner individuals will experience during a fat loss phase. They have more stored energy to pull from, they can lose weight on higher calories, and hunger should not be excessive when their diet is set up well. These individuals will however require a longer period of dieting, and can therefore benefit from diet breaks, although the frequency of their diet breaks can be lower than leaner individuals.

Here are some general guidelines for the frequency and duration of diet breaks, although these should be based on the individual, and factors such as age, stress levels, hunger levels, sleep quality, training volume, and experience, as well as personality type, should be taken into consideration.

During a diet break, we have a couple of different options we can use:

option 1: Continue to track and increase calories by 20-25%

For most people, we recommend continuing to track calories, increasing them by around 20-25%. Your true maintenance calories may be different from what it was at the beginning of a fat loss phase, due to some downregulation of metabolic rate. This will depend on the amount of time you have been dieting and how lean you are. Some people have a more adaptive metabolic rate while others have a less adaptive one, meaning their metabolic rate is less affected by a calorie deficit.

Option 2: stop all food tracking

Some individuals can benefit from not tracking their calories or macros during a diet break. This can be a nice psychological break from tracking, and this can be more or less important depending on how an individual views tracking. There is more of a risk of overeating here, and this may be better used for individuals with more experience in estimating their maintenance levels, by using things such as hunger levels, and keeping the same meal structure as they were when tracking.

increase calories mostly from carbohydrates

We recommend the majority or all of your extra calories come from carbohydrates during a diet break. Carbohydrates are great at reducing cortisol and stress in general and will refill glycogen (stored carbohydrates in muscle). They can also improve things such as sleep quality. If fat has been low during a fat loss phase, this can be raised a little to allow for some extra flexibility in our food choices during a diet break.

time your diet breaks with deload or rest weeks

Taking a diet break on a deload or rest week can be a great idea. The increased calorie intake combined with a break from strength training, even for one week, will reduce fatigue and stress, allowing for some much needed recovery and can prepare you well for the rest of your fat loss phase.

reduce cardio by 50%

If you have been performing regular cardio during your fat loss phase, reducing this by around 50% is a good idea. You can also reduce the intensity a little. We recommend you do not perform any high-intensity cardio to allow for extra recovery.

consider walking

You can even scrap cardio altogether for a week or two if you feel you need to and instead use walking to ensure your activity levels do not drop too much. Walking is low stress and will likely improve your recovery, compared to performing higher-intensity cardio or doing no activity at all.

Diet breaks are typically planned in advance, although we can also use an autoregulated approach. Taking a diet break when we feel we need one can be a good option, such as when we are feeling excessive fatigue or hunger levels, when sleep quality is poor, or when we feel performance in the gym is suffering. If we have an unexpected stressful situation, or we know the next week or two are likely to be overly stressful and/or busy, taking a diet break is probably a good idea.

Diet breaks can also be based on lifestyle factors and timed to fit around certain times of the year, such as holiday periods, vacation times, or any time you would like a little bit more flexibility in your food choices and you know sticking to a calorie deficit is not going to be practical. These are great times to use a diet break and is something we recommend.

If you take regular planned diet breaks you may feel you do not need one, and this can be a good thing. It is probably better to take a diet break before any symptoms that indicate you need one appear. If you are using an autoregulated approach, or you do not intend to take a diet break, however, one or more of the following symptoms appear, this may indicate it could be a good idea to take one.

your fatigue is high and your gym performance has decreased

Fatigue will be higher and training performance will be somewhat decreased in a fat loss phase, depending on the amount of time you have been dieting, the amount of calories you are consuming, and your level of leanness. However, if you suddenly experience excessive amounts of fatigue, and you notice your strength in the gym has dropped considerably, this may be a good indication that a diet break is needed.

your motivation to train is low

If you usually love to train, and you notice that your motivation to train is not there anymore, taking a week or two at maintenance calories, while also taking a deload or rest week can be a great option. After some extra food and recovery, you should be eager to get back in the gym and continue with your fat loss phase.

you are dealing with excessive hunger

Some degree of hunger is expected in a fat loss phase, however, if you are dealing with excessive amounts of hunger, you are miserable and irritable, and you believe you are likely to break from your diet plan in the near future, a diet break could be just what you need. Rather than feeling guilty because you were unable to keep to your calorie targets, intentionally raising calories would be a better option.

your sleep quality is poor

If your sleep quality has gotten noticeably worse, this could be a sign that it is a good time to implement a diet break. If you struggle to fall asleep, even though you feel tired (tired and wired), you wake up during the night, usually in the early hours, and you feel unrefreshed upon waking, this is a sign that cortisol is high. Adding in some extra calories, especially carbohydrates, and reducing the amount of exercise you are performing will help bring cortisol levels down.

you feel more stressed than normal

If you feel more stressed in general, are irritable, and your mood is low, this is another indication that you should raise calories and implement a diet break.

your weight loss has stalled and your calories are already low

If your weight loss has stalled, your calories are already low, and you are unable to perform more activity a diet break can be a good option. Recent studies have shown short diet breaks do not affect metabolic rate to any significant degree, so a longer diet break may be required. This could be up to 4 weeks or even longer, to allow the metabolic rate to recover, and can result in fat loss on higher calories once you return to a calorie deficit.

It is important to establish whether you have reached a true fat loss plateau. Things to consider are the accuracy of your food tracking as well as how you track your body weight. Day-to-day scale weight fluctuations are normal, and water retention can mask any fat loss you may be achieving. This is why we recommend taking a 7-10 day average weight and comparing that to the previous week. Weigh yourself first thing in the morning, before eating, and after using the bathroom, to establish any trends in body weight over a 7-10 day period.

Making sure you are in a net energy balance over the week is also important. You may be in a calorie deficit for 5 or 6 days of the week, but some higher days can easily put your average weekly calories at maintenance resulting in no fat loss. This is a common problem, with the weekends usually being the main culprit!

Diet breaks and refeed days are similar, although they serve different purposes, and are on different time scales. Refeed days are typically performed weekly and usually involve one or two days where calories are raised to around maintenance, mostly from carbohydrates. An example of this would be if you were calorie cycling, using the 5:2 calorie cycling protocol.

Refeed days provide a nice psychological break from dieting and can also help restore some muscle glycogen. The same average weekly energy deficit will need to be in place to achieve fat loss at the same rate as you would if you were in a straight calorie deficit. Although refeed days may help reduce some fatigue, one or two days are not sufficient to bring down excessive fatigue, both physical and psychological, built up over a fat loss phase. This is why raising calories for longer periods is beneficial and is why diet breaks can be useful.

There are no real downsides to using diet breaks, the only negative, for some people at least, is that it will take slightly longer to achieve the same amount of fat loss, compared to if you had remained in a calorie deficit for the duration of a fat loss phase, without any periods at maintenance calories.

If you have not used diet breaks before it can be a good idea to experiment with a diet break in your next fat loss phase. You may find significant benefits or you may find none, it can be a very individual thing. You will likely find greater benefits when you are getting below 12% body fat and your calories are low. If you are dieting from 20-15% body fat or even down to 12% for 8-12 weeks you may not need a diet break. If you have a lot of body fat to lose and will be dieting for a significant period you could use a diet break every 12-16 weeks.

Using diet breaks in a fat loss phase is a useful strategy and may even help you achieve fat loss more effectively compared to remaining in a calorie deficit for the duration of your fat loss phase. The main benefits of diet breaks seem to be increased adherence to a nutrition plan and can therefore help you achieve your weight loss goal more easily and enjoyably.