Study: Nighttime eating worsens feelings of anxiety, depression

Key takeaways

• A study simulating night work revealed that eating at night may increase feelings of depression and anxiety.
• Worsened depressive feelings were linked to internal circadian misalignment.
• The researchers emphasized that future studies are needed to establish a causal relationship.

Researchers discovered evidence that meal timing has significant effects on anxiety- and depression-like mood levels, which were connected with internal circadian misalignment.

“Our findings provide evidence for the timing of food intake as a novel strategy to potentially minimize mood vulnerability in individuals experiencing circadian misalignment, such as people engaged in shift work, experiencing jet lag, or suffering from circadian rhythm disorders,” Frank A. J. L. Scheer, PhD, co-author of the study and director of the Medical Chronobiology Program in the division of sleep and circadian disorders at Brigham and Women’s Hospital, said in a press release. “Future studies in shift workers and clinical populations are required to firmly establish if changes in meal timing can prevent their increased mood vulnerability. Until then, our study brings a new ‘player’ to the table: the timing of food intake matters for our mood.”

The study, published in the Proceedings of the National Academy of Sciences, simulated night work and tested the effects of meal timing. The researchers were able to assess mood variability with a “stringently controlled 14-d circadian paradigm.”

For people who ate both in the daytime and nighttime, anxiety-like mood levels increased by 16.1% (pFDR = 0.001; effect-size r = 0.47) and depression-like mood levels increased by 26.2% (pFDR = 0.001; effect-size r = 0.78). People who ate only in the daytime did not report the increases, which led the researchers to believe that meal timing could affect mood.

The researchers also wrote that, “importantly, a larger degree of internal circadian misalignment was robustly associated with more depression-like (r = 0.77; P = 0.001) and anxiety-like (r = 0.67; P = 0.002) mood levels during simulated night work.”

Previous research has found that shift workers face a 25% to 40% elevated risk of depression and anxiety, which in part is due to a misalignment of their circadian clock and daily emotional/behavioral cycles. Therefore, Scheer and colleagues wrote, “evidence-based circadian interventions are required to prevent mood vulnerability in shift work settings.”

“Shift workers — as well as individuals experiencing circadian disruption, including jet lag — may benefit from our meal timing intervention,” Sarah L. Chellappa, MD, PhD, co-author of the study and a physician in the department of nuclear medicine at the University of Cologne in Germany, said in the release. “Our findings open the door for a novel sleep/circadian behavioral strategy that might also benefit individuals experiencing mental health disorders. Our study adds to a growing body of evidence finding that strategies that optimize sleep and circadian rhythms may help promote mental health.”

Though Chellappa said in the release that “meal timing is emerging as an important aspect of nutrition” that could affect one’s physical health, “the causal role of the timing of food intake on mental health remains to be tested.”

“Future studies are required to establish if changes in meal timing can help individuals experiencing depressive and anxiety/anxiety-related disorders,” Chellappa continued.

References:

• Daytime eating may benefit mental health. https://www.eurekalert.org/news-releases/964188. Published Sept. 12, 2022. Accessed Sept. 13, 2022.
• Qian J, et al. Proc Natl Acad Sci USA. 2022;doi:10.1073/pnas.2206348119.