Can food combat bad moods? A new study provides further evidence that mealtimes can influence mental health, including the extent of mood swings caused by depression and anxiety.

Timing of Food Intake could be Crucial in Reducing Mood Swings

Researchers at Brigham and Women’s Hospital, a founding member of the Mass General Brigham health system, developed a study that simulated night work and then examined the effects of meals during the day and at night compared to meals during the day only. The team found that participants in the group that ate during the day and at night experienced a 26 percent increase in depression-like moods and a 16 percent increase in anxiety-like moods. Participants in the group that ate only during the day did not experience this increase, suggesting that the timing of meals may influence susceptibility to mood swings. 

“Our findings provide evidence that the timing of food intake is a novel strategy to potentially minimize mood fluctuations in individuals with circadian misalignment, such as shift workers, individuals with jet lag, or individuals with circadian rhythm disorders,” said co-author Frank A. J. L. Scheer, PhD, director of the Medical Chronobiology Program in the Division of Sleep and Circadian Disorders at Brigham. “Future studies with shift workers and clinical populations are needed to definitively determine whether changing meal times can prevent their increased susceptibility to mood swings. Until then, our study brings a new ‘factor’ into play: the timing of food intake is important for our mood.”

Shift workers make up as much as 20 percent of the working population in industrialized societies and are directly responsible for many hospital services, factory work, and other essential services. Shift workers often suffer from a misalignment between their central circadian clock in the brain and their daily behaviors, such as sleep/wake and fasting/eating cycles. Importantly, they also have a 25 to 40 percent higher risk of depression and anxiety. “Shift workers—as well as individuals who suffer from circadian rhythm disorders, including jet lag—may benefit from our intervention regarding meal times,” said co-author Sarah L. Chellappa, MD, PhD, who completed her work on this project during her time at Brigham. “Our findings open the door to a novel sleep/circadian rhythm strategy that could also benefit people with mental health disorders. Our study adds to the growing body of evidence that strategies to optimize sleep and circadian rhythm may contribute to mental health.”

Eating in the Evening Led to an Increase in Depression and Anxiety Among Participants

To conduct the study, Scheer, Chellappa, and their colleagues recruited 19 participants (12 men and 7 women) for a randomized controlled trial. Participants underwent 28-hour “days” of forced desynchronization under dim lighting for four days, so that by the fourth “day” their behavioral cycles were shifted by 12 hours, simulating night work and causing circadian misalignment. Participants were randomly assigned to one of two groups with different meal times: the day and night meal control group, which consumed meals on a 28-hour cycle (resulting in meals during both night and day, which is typical for night workers), and the day meal intervention group, which consumed meals on a 24-hour cycle (resulting in meals only during the day).

The team assessed the extent of depressive and anxiety-like moods on an hourly basis. The team found that meal times had a significant impact on participants’ moods. During the simulated night shift (day 4), participants in the control group for daytime and nighttime meals showed an increase in depression-like and anxiety-like moods compared to baseline (day 1). In contrast, there were no changes in mood in the daytime meal intervention group during the simulated night shift. Participants with a higher degree of circadian misalignment showed stronger depressive and anxiety-like moods. “Meal timing is emerging as an important aspect of nutrition that can influence physical health,” Chellappa said. “However, the causal role of meal timing in mental health still needs to be investigated.”