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Written by Clean Health Online Master Coach Kim Leggett

If you’ve been through a diet, which chances are you have at some point in your life, you will have encountered some muscle loss and negative metabolic adaptations. After all, you’ve spent a prolonged period of time in a caloric deficit.

This doesn’t sound very good, but this is where DIET BREAKS come in!

What is a diet break?

A diet break is simply a longer period, typically 1-2 weeks of returning to maintenance calories. 

Several recent studies have shown that diet breaks can improve weight loss efficiency by offsetting some of the negative metabolic adaptations in response to caloric restriction.1,2 Weight loss efficiency here meaning that you can achieve greater weight loss for the period that you are in a caloric deficit. 

That should not be confused with faster weight loss. Although you might be losing weight faster while you are in a deficit, you are also spending time not being a deficit at all when you take a diet break, which can increase the total time required to achieve the same weight loss. 

Great, but do they work?

The famous MATADOR study3 showed 2 groups of individuals who were placed on a 16 week isocaloric diet. One group dieted all the way through while the other group dieted two weeks on two weeks off. At the end, the group that dieted two weeks on and two weeks off lost significantly MORE weight, approximately 50% more, and had a much lower reduction in resting metabolic rate. 

More importantly, they maintained MORE of the weight lost after a six-month follow up. It must be mentioned that this group took 32 weeks instead of 16 given the diet breaks EXTENDED their dieting phase. 

How you can use diet breaks effectively

So, even though diet breaks sound awesome (and they are), they’re NOT for everyone. If someone is steadily losing weight and all their biofeedback markers such as energy, appetite, and libido are fine then there is no need to give them a diet break. 

The 12-week timeframe is typically for those who are moderately lean whilst more overweight clients will need to stay in a deficit for at least 16 weeks. Again this will always vary from client to client, so if structured diet breaks are NEEDED for adherence purposes then include them for your client. 

A good rule of thumb is that leaner clients get a 1-2 week diet break every 6-8 weeks if they have had regular refeeds or a one week diet break for every 2-3 weeks when not having a refeed. Overweight clients typically do not get given refeeds as they do not risk losing muscle mass.

Diet breaks for these clients are every 6-8 weeks or a 2-4 week maintenance phase every 12-16 weeks. 

No matter the client you have, there’s one very important caveat. ‘Diet break’ does NOT mean you can eat whatever you want. It’s a break from the deficit but not a break from your diet or caring about what you put in your mouth to fuel your body. Another thing to consider is the cost-benefit of having a diet break as the more you have, the longer your overall dieting process becomes. 


1. Wing RR, Jeffery RW. Prescribed “breaks” as a means to disrupt weight control efforts. Obes Res. 2003;11(2):287-291. doi:10.1038/oby.2003.43

2. Byrne NM, Sainsbury A, King NA, Hills AP, Wood RE. Intermittent energy restriction improves weight loss efficiency in obese men: The MATADOR study. Int. J. Obes. 2017 doi: 10.1038/ijo.2017.206.

3. Sainsbury A, Wood RE, Seimon RV, et al. Rationale for novel intermittent dieting strategies to attenuate adaptive responses to energy restriction. Obes Rev. 2018;19 Suppl 1:47-60. doi:10.1111/obr.12787

4.Norton, Layne.(PhD). (2018).Diet Braks: how and why to use them. Retrieved from:

5. Clean Health Fitness Institute. (2020). Performance Nutrition Coach Level 2. CHFI. 

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