What you eat definitely affects the quality of your sleep. But can ultra-processed food (UPF) keep you awake at night? Researchers now say that they are responsible for insomnia in one-third of adults.

Ultra-processed foods are designed for extended shelf life and contain higher levels of fat, sugar, and salt. They are typically mass-produced and industrially processed.

According to a study published in the Journal of the Academy of Nutrition and Dietetics, the consumption of ultra-processed food has a significant association with chronic insomnia.

"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 lead investigator Marie-Pierre St-Onge.

"Our research team had previously reported associations of healthy dietary patterns, like the Mediterranean diet, with a reduced risk of insomnia and poor sleep quality (both cross-sectionally and longitudinally), and high carbohydrate diets with an elevated risk of insomnia. The consumption of UPF is on the rise worldwide, and it has been linked to numerous health conditions such as diabetes, obesity, and cancer," St-Onge added.

The study involved analyzing over 39,000 French adults regarding different aspects of their sleep patterns and documenting their dietary habits. From 2013 to 2015, the researchers gathered detailed information about the participants' diets through multiple 24-hour dietary records taken every six months.

During the study, participants indicated that roughly 16% of their energy intake was sourced from ultra-processed foods, and approximately 20% reported experiencing chronic insomnia.

"Individuals who reported chronic insomnia consumed a higher percentage of their energy intake from UPF. The association of higher UPF intake and insomnia was evident in both males and females, but the risk was slightly higher in males than females," the news release stated.

The study is based on self-reported data, and there are possibilities that certain food items could have been misclassified. Researchers said caution must be taken when generalizing the findings, as the study population had a higher proportion of females and participants from high socioeconomic status compared with the general French population.

"It is important to note that our analyses were cross-sectional and observational in nature, and we did not evaluate longitudinal association. While data do not establish causality, our study is first of its kind and contributes to the existing body of knowledge on UPF," first author Pauline Duquenne said.

Although there is no causal association, the researchers suggest that individuals experiencing sleep difficulties should consider evaluating their diet to determine if it plays a role in their sleep problems.