Do diet breaks help?
Mostly for your head, not your fat loss: a week at maintenance now and then changes little on the scale, but it makes a long diet easier to run.
The two trials point different ways. In trained women on a 25% deficit, breaks made no difference to fat loss or resting metabolism over six weeks. In men with obesity dieting for much longer, the group that alternated two weeks on and two weeks at maintenance ended up losing more fat, though it took almost twice as long in calendar weeks.
What both show is that a break does not undo your progress. So use one when the diet is getting heavy: a week at maintenance, protein kept high, training unchanged. Take it as a planned pause, not as a reason to stop counting.
Run the numbers
Compare
Sources
3
- Siedler, M.R. et al. (2023). The effects of intermittent diet breaks during 25% energy restriction on body composition and resting metabolic rate in resistance-trained females: a randomized controlled trial. J Hum Kinet 86. 38 trained women: breaks gave no advantage in fat loss or resting metabolism, but the break group scored better on one eating behaviour measure.
- Byrne, N.M. et al. (2018). Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study. Int J Obes 42(2). Men with obesity on two weeks of dieting alternated with two weeks at maintenance lost more fat (12.3 kg) than a continuous diet (8.0 kg), over a longer calendar period.
- Trexler, E.T. et al. (2014). Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr 11(1). The reasoning behind breaks: dieting lowers energy burned beyond the weight lost.