Taking a two-week break from a diet actually helps people lose 50% more weight, new research demonstrates.
Intermittent dieting also helps keep the weight off, the researchers found.
The study compared two groups: one that dieted continuously for 16 weeks.
The other group, though, dieted two weeks on and two weeks off for a total of 32 weeks, thereby including 16 weeks of dieting.
Those who dieted continuously lost an average of 20 pounds (9 kg), while those who dieted intermittently lost 31 pounds (14 kg).
The intermittent dieters also maintained 18 pounds less weight six months after the end of the study.
Professor Nuala Byrne, the study’s first author, said:
“When we reduce our energy (food) intake during dieting, resting metabolism decreases to a greater extent than expected; a phenomenon termed ‘adaptive thermogenesis’ — making weight loss harder to achieve.
This ‘famine reaction’, a survival mechanism which helped humans to survive as a species when food supply was inconsistent in millennia past, is now contributing to our growing waistlines when the food supply is readily available.”
Shorter breaks from dieting are not as effective, said Professor Byrne:
“There is a growing body of research which has shown that diets which use one to seven day periods of complete or partial fasting alternated with ad libitum food intake, are not more effective for weight loss than conventional continuous dieting.
It seems that the ‘breaks’ from dieting we have used in this study may be critical to the success of this approach.
While further investigations are needed around this intermittent dieting approach, findings from this study provide preliminary support for the model as a superior alternative to continuous dieting for weight loss.”
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
The study was published in the International Journal of Obesity (Byrne et al., 2018).