Late Night Eating Linked to Depression and Anxiety

A 2022 study found that eating at night can have a negative impact on your mood. The study, conducted by researchers at Harvard Medical School’s Brigham and Women’s Hospital (BWH) in the United States, found that nighttime eating can increase feelings of depression and anxiety.

Reasearchers enrolled 19 participants and randomly put them into a Daytime and Nighttime Meal Control Group, which had meals according to a 28-hour cycle (typical among night shift workers), and a Daytime-Only Meal Intervention Group, which had meals on a 24-hour cycle, eating only during the day. They then surveyed the participants and found that, by the fourth day, the participants with a greater degree of “circadian misalignment” began experiencing feelings of depression and anxiety.

By simulating night shift conditions and disrupting their eating pattern, the feedback from participants in the Nighttime Meal Control Group indicated that feelings of anxiety and depression had risen by 16% and 26%. However, there was no increase in anxiety and depression in the group who only ate during the day, indicating that meal timing may affect people’s moods.

Frank Scheer, Director of the Medical Chronobiology Program in BWH’s Division of Sleep and Circadian Disorders and co-coordinating author of the study, said that the findings show that people who do shiftwork, experience jet lag, or have irregularities in their sleeping pattern, have a high probability of experiencing mood disorders.

Shift workers make up around 20% of the labour force and are integral to the running of hospitals, manufacturing and many other essential services. However, unfortunately, working irregular hours often disrupts the balance between the brain’s internal clock and regular activities like eating. This means that shift workers also face a 25% to 40% greater risk of developing anxiety and depression.

Dr. Sarah Chellappa, who was also a co-coordinating authored of the study and now works in the Department of Nuclear Medicine at the University of Cologne in Germany, said that those individuals experiencing circadian disruption could benefit from “meal time intervention”. She added that the findings suggest that there is a possibility of introducing a “sleep/circadian behavioural strategy” that might also benefit other individuals experiencing mental health disorders.

Whilst this was only a small sample study, more needs to be done to establish if changes in eating times can help people suffering from mood disorders said Chellappa. “Meal timing is emerging as an important aspect of nutrition that may influence physical health,” she said, but “the causal role of the timing of food intake on mental health remains to be tested”.