Episode 134 – Diet Breaks VS Refeeds

Key Topics Covered

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Defining Diet Breaks and Refeeds

  • Refeeds or cheat meals/days typically involve either a day or meal that is significantly higher in calories than what is regularly consumed. 
  • Often a refeed is strategically higher in carbs.
  • ‘Refeeds’ is probably a more ideal term, as the word ‘cheating’ has the connotation that this is a bad thing.
  • Refeed days could either be at maintenance or they could be to a surplus.
  • On the other hand, a diet break is an extended period of eating at maintenance calories. I’d define it as 1-4 weeks. Any longer than that and it’s probably just a maintenance phase.

Metabolism/Fat Loss

Refeeds

  • People often propose that a refeed can “spike” metabolism.
  • When looking at hormones and metabolic rate in the short term, we do see spikes that reflect this.
  • The issue is just that when you take a broader look, the impact is minimal.
  • The changes are too short-term. It is pretty much guaranteed that the changes have less of an impact over a longer timeframe than the actual change in calorie intake itself.

Diet Breaks

  • With diet breaks, there likely is an impact on metabolic rate.
  • But there are a few studies we will discuss to go through that:
  1. The MATADOR Trial
  • 2 weeks on, 2 weeks off for a total of 30 weeks, vs 16 weeks of straight dieting.
  • Greater weight loss was achieved in the diet break group and energy expenditure remained higher.
  • Caveats:
  • That it involved 30 weeks vs 16. That’s hugely prolonging the process.
  • It was an outpatient type of study. One major criticism is just that they might have lost more weight due to sticking to the plan better.
  1. The ICECAP Trial
  • 3 weeks on 1 week off, for 15 weeks, vs 12 weeks straight dieting.
  • Fat loss came out the same. No difference in metabolic adaptation was observed.
  1. Metabolic Adaptation is an illusion, only present when participants are in negative energy balance
  • 4 weeks at maintenance was enough to pretty much completely offset metabolic adaptation to the point it was no longer really even measurable.

Therefore whether diet breaks affect metabolic adaptation and fat loss really depends on the duration.

Appetite Management

Women looking in fridge.

  • A figure from the Icecap trial highlights that those who dieted for 12 weeks straight had significant increases in hunger and desire to eat.
  • The diet break group barely had any increase, even though they lost as much body fat.
  • Refeeds likely don’t help here much – particularly because for things to balance out you need to reduce intake a bit more on other days to make it work out.

Lean Mass Retention

Women tensing back muscles.

  • Refeeds don’t have research supporting helping lean mass retention.
  • You could make a practical argument that maybe they help in some cases.
  • For example in a bodybuilding prep, doing refeed days on lagging muscle groups has been proposed to help preserve more muscle in that area. OR alternatively, doing it on leg days, which are harder days, particularly when on low calories. 

Refeeds

  • The 2-Day Refeed Study by Bill Campbell et al., in 2020 looks more promising on the topic.
  • They compared a 25% calorie deficit 7 days per week vs a 35% deficit 5 days per week with 2 days at maintenance. This went for 7 weeks.
  • The refeed group maintained more lean mass, with 0.5kg vs 1.5kg.
  • One proposed issue here is that the measurements were taken 2 days after the last refeed. Some people have highlighted that there might still be higher glycogen/water levels in the refeed group, making the muscle difference smaller.

Diet Breaks

  • It’s difficult to state the effects of diet breaks.
  • They likely help with lean mass retention if done frequently and for decent durations.
  • But that’s less to do with the magic of diet breaks and more to do with just training consistently with a decent amount of calories.
  • You’d need to weigh up the pros and cons of the added time that diet breaks add versus just getting the deficit done and then increasing calories at the end.

Mental/Psychological Perspective

Brain with food.

Refeeds

  • Flexibility – a refeed could be a chance to be flexible with food e.g. once per week have something high carb/calorie. This could also align with a social event. 
  • Some people really look forward to a refeed.
  • Everything comes with a cost though e.g. to make room for a refeed, you need to reduce calories slightly during the rest of the week, reducing flexibility elsewhere. 
  • For some people, refeeds or cheat meals can build an association of good vs bad thinking.

Diet Breaks

  • Diet breaks planned in advance can allow people to push a bit harder knowing the break is coming up. 
  • The break gives a chance to be more flexible with food + focus more on fuelling for training etc.
  • It also gives a chance to “practice maintenance” which can be relevant for a lot of people.
  • Could line up with holidays or other events if desired.
  • One downside is that it can break the momentum. Some people struggle to switch back into a deficit after doing a diet break. Although I’d argue that the ability to change phases is also a skill that is worth having as well.

Summary

  • There are pros and cons to both.
  • For example, diet breaks can help quite a lot with aspects such as appetite.
  • Both have an impact on the psychological standpoint
  • Overall they can be beneficial for some people and not so much for others.
  • Diet breaks also add time on to the journey, so this is worth considering.
  • Everything needs to be weighed up for you and your specific circumstances.

Relevant Blogs / Resources

Blog Posts

Studies Mentioned