It’s long been known that what you eat can affect how you sleep. Research has shown, for example, that adopting a Mediterranean-style diet may improve sleep quality, while a diet high in carbohydrates may promote insomnia.
With an estimated one in every three adults experiencing insomnia, understanding the link between diet and sleep quality is more important than ever—especially if what we’re eating is causing our lack of sleep. “At a time when more and more foods are highly processed and sleep disturbances are rampant, it is important to evaluate whether diet could contribute to adverse or good-quality sleep,” said Marie-Pierre St-Onge, PhD, of the Center of Excellence for Sleep & Circadian Research at Columbia University and lead investigator of a new study that set out to do just that. The results were published in the Journal of the Academy of Nutrition and Dietetics.
Rather than investigating the effect of certain nutrients, eating patterns, or dietary supplements on sleep, St-Onge and her team set out to evaluate whether the degree to which foods are processed could have an impact on sleep health.
To examine dietary intakes for their association with sleep, this large epidemiological study used data from the NutriNet-Santé study, a large-scale attempt to evaluate the correlation between nutrition and health that was launched in 2009. The more than 170,000 French adults participating in NutriNet-Santé routinely fill out online questionnaires that provide “extensive, high-quality nutritional and non-nutritional data, including repeated data on socio-demographics and lifestyle (yearly), anthropometrics (every 6 months), dietary intake (every 6 months), physical activity (IPAQ questionnaire, yearly)5 and health status (every 6 months).”
To investigate the relationship between processed foods and sleep, St-Onge’s team analyzed data from more than 39,000 NutriNet-Santé participants who completed multiple 24-hour dietary records and provided information on insomnia symptoms every 6 months between 2013 and 2015. Criteria for insomnia were taken from the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the International Classification of Sleep Disorders, Third Edition (ICSD-3).
Overall, participants reported consuming approximately 16% of their calories from ultra-processed food (UPF) and close to 20% reported chronic insomnia. Individuals who reported chronic insomnia consumed a higher percentage of their caloric intake from UPF. While the association between higher UPF intake and insomnia was evident in both males and females, the risk of insomnia was slightly higher in males.
Conclusions
While these results add to the growing body of evidence that UPF presents significant health risks, the investigators warn that their study is by no means definitive. “It is important to note that our analyses were cross-sectional and observational in nature, and we did not evaluate longitudinal association,” said lead author Pauline Duquenne, MSc, of Sorbonne Paris Nord University. “While data do not establish causality, our study is the first of its kind and contributes to the existing body of knowledge on UPF.” Other study limitations included reliance on self-reported data and possible misclassification of some food items.
The investigators recommend that future studies should test causality and evaluate the associations between UPF and insomnia over time. In the meantime, however, they advise that individuals with sleep issues consider examining their diet to determine whether UPF could be contributing to the problem.
