An entirely vegetarian diet was associated with lower risk of obstructive sleep apnoea and higher frequency of hypnic jerks compared to an omnivorous diet, while sleep quality, insomnia symptoms, and sleepiness did not differ between dietary groups.
Key Findings
Results
Vegetarian participants showed a lower risk of obstructive sleep apnoea (OSA) compared to omnivores.
Sample included 747 participants: 532 omnivores and 215 vegetarians.
Dietary pattern predicted OSA risk in multiple regression models, with greater OSA risk in omnivores.
The association between vegetarian diet and lower OSA risk remained significant after controlling for other variables including sociodemographic factors, Mediterranean diet adherence, mental health, eating disorder symptomatology, and chronotype.
Data were collected via online self-reported survey measuring obstructive sleep apnoea risk.
Results
Vegetarian participants reported a higher frequency of hypnic jerks compared to omnivores.
Hypnic jerks were among the sleep-related movement disorders assessed in the survey.
Dietary pattern predicted hypnic jerk frequency in multiple regression models, with higher frequency in vegetarians.
This association persisted after controlling for confounding variables.
No significant differences were found between groups in other sleep-related movement disorders.
Results
Vegetarian participants showed a lower tendency toward eveningness (i.e., were less likely to be evening chronotypes) compared to omnivores in bivariate comparisons.
Chronotype was assessed as part of the survey measures.
The difference in eveningness was observed in initial group comparisons between vegetarians and omnivores.
However, chronotype was treated as a covariate rather than an outcome in the multiple regression models, so this finding reflects a bivariate association.
Results
Vegetarian and omnivorous participants did not differ significantly in sleep quality, insomnia symptoms, or daytime sleepiness.
Sleep quality, insomnia symptoms, and sleepiness were all assessed via self-reported measures in the online survey.
Multiple regression models confirmed that dietary pattern did not predict these sleep outcomes after controlling for other variables.
The authors note that results on the relationship between entirely vegetarian diets and sleep are 'scarce and heterogeneous.'
This finding contrasts with some prior literature suggesting plant-based diets broadly benefit sleep quality.
Results
Multiple regression models confirmed that dietary pattern independently predicted only OSA risk and hypnic jerk frequency after accounting for confounding variables.
Confounding variables controlled for included sociodemographic variables, adherence to the Mediterranean diet, mental health, eating disorder symptomatology, and chronotype.
Among all sleep outcomes assessed (sleep quality, insomnia, sleepiness, OSA risk, sleep-related movement disorders), only OSA risk and hypnic jerks were independently predicted by dietary group.
The authors emphasize 'the importance of controlling for other confounding factors to reach a more nuanced understanding of the relationship between dietary patterns and sleep.'
Methods
The study used an online survey design to collect entirely self-reported data on diet and sleep from an Italian sample.
Data were collected via an online survey assessing dietary patterns, sleep quality, insomnia symptoms, sleepiness, OSA risk, and sleep-related movement disorders.
Additional variables collected included sociodemographic data, Mediterranean diet adherence, mental health, eating disorder symptomatology, and chronotype.
The final sample was 747 participants (532 omnivores, 215 vegetarians), recruited in Italy.
All measures were self-reported, which is a limitation of the study design.
What This Means
This research suggests that following a completely vegetarian diet is linked to certain differences in sleep compared to eating an omnivorous diet, but the relationship is more specific than a general improvement in sleep. Among 747 Italian adults surveyed online, those who ate a vegetarian diet were less likely to be at risk for obstructive sleep apnea (a condition where breathing repeatedly stops during sleep) and more likely to experience hypnic jerks (the sudden muscle twitches or 'falling' sensations that some people feel when drifting off to sleep). Importantly, there were no meaningful differences between vegetarians and omnivores in overall sleep quality, insomnia, or daytime sleepiness.
The researchers also found that when they accounted for other factors — such as mental health, chronotype (whether someone is a morning or evening person), adherence to the Mediterranean diet, and eating disorder symptoms — the vegetarian diet only independently predicted the lower sleep apnea risk and higher hypnic jerk frequency. This means that some apparent diet-sleep links may actually be explained by these other lifestyle and health factors rather than diet alone.
This research suggests that the connection between a vegetarian diet and sleep is nuanced: it may offer specific benefits like reducing sleep apnea risk, while also being associated with more frequent hypnic jerks. The findings highlight the importance of looking at multiple aspects of sleep rather than just overall sleep quality, and of accounting for the many lifestyle factors that often accompany vegetarian diets when studying their effects on health.
Gorgoni M, Comparelli A, Frappetta S, Alfonsi V, Annarumma L, Pellegrini E, et al.. (2026). Sleeping green: an Italian survey for the assessment of the relationship between sleep and vegetarian diet.. Sleep & breathing = Schlaf & Atmung. https://doi.org/10.1007/s11325-026-03593-3