Npj biological timing and sleepJul 20, 2026

Social jetlag is linked to eating more calories in the evening in a UK group

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗OA ↗

Updated Jul 21, 2026

Abstract

In a study with 101 participants, increasing social jetlag levels was associated with later energy intake.

Social jetlag refers to the mismatch in sleep timing between workdays and weekends.
Higher levels of social jetlag were linked to greater evening energy intake among participants.
Participants with less social jetlag tended to consume energy earlier in the day.
The effect of social jetlag on energy intake varied between weekdays and weekends and differed by sex.
The overall impact of social jetlag on energy intake was modest and unlikely to fully account for increased obesity and metabolic disease risks.

Simplified

Social jetlag describes the differences in sleep timing between workdays and weekends. In a 14-day longitudinal observational study, we explored the associations between social jetlag and energy intake on workdays and weekends. Healthy male and female participants residing in the UK [n = 101] used a smartphone app to record dietary intake continuously during the study period, encompassing two working weeks and weekends. We hypothesised that higher social jetlag levels would be associated with greater evening energy intake. Using regression models with complementary social jetlag classifications, we found that increasing social jetlag levels modified temporal energy intake in both female and male participants. Overall, participants with less social jetlag exhibited earlier energy intake, while participants with more social jetlag exhibited later energy intake, although the modifying effect of social jetlag differed slightly between weekdays and weekends and the sexes. Importantly, however, the magnitude of the effect estimates was modest and, in caloric terms, unlikely to explain the higher risks of obesity and metabolic diseases previously associated with increasing social jetlag levels.

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Funding

Competing interests

Competing interests: J.D.J. has collaborated with Nestlé and has undertaken consultancy work for Kellogg’s and International Flavors and Fragrances (IFF). A.F. is a director of Alinea Nutrition Ltd. and declares no non-financial competing interests. The other authors do not have a competing interest.

PubMed

Social jetlag is linked to eating more calories in the evening in a UK group

Abstract

Full Text

Funding

Competing interests

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