Summary: When you eat may influence symptoms of depression and anxiety, according to a controlled laboratory study.
Source: Brigham and Women’s Hospital
Meal timing appears to influence mood vulnerability. A controlled study by investigators at Brigham and Women’s Hospital examined whether eating only during the daytime versus eating during both day and night changes levels of depression- and anxiety-related mood when sleep and wake cycles are shifted to simulate night work.
In this experiment, participants who ate both during the day and at night showed a 26 percent increase in depression-like mood and a 16 percent increase in anxiety-like mood during the simulated night work period. Participants who ate only during daytime hours did not show these mood increases, suggesting that the timing of food intake can affect emotional responses when circadian rhythms are disrupted.
The study appears in the Proceedings of the National Academy of Sciences.
“Our findings provide evidence that the timing of food intake is a potentially important strategy to minimize mood vulnerability when people experience circadian misalignment — for example, during shift work, after jet lag, or with circadian rhythm disorders,” said Frank A. J. L. Scheer, PhD, Director of the Medical Chronobiology Program in the Brigham’s Division of Sleep and Circadian Disorders.
Co-corresponding author Sarah L. Chellappa, MD, PhD, added that future studies in actual shift workers and people with clinical mood disorders are needed to determine whether changing meal timing can help prevent mood problems. “Our results add to growing evidence that strategies to optimize sleep and circadian rhythms — including when we eat — could benefit mental health,” she said.
Shift workers make up as much as one-fifth of the workforce in many industrial societies and are essential to hospitals, factories, transport and public services. They frequently experience misalignment between the central circadian clock in the brain and daily behaviors such as sleep/wake cycles and eating schedules. That misalignment has been linked to a 25–40 percent increased risk of depression and anxiety.
To test the role of meal timing, researchers recruited 19 healthy adults (12 men and 7 women) into a tightly controlled, randomized study. Participants completed a Forced Desynchrony protocol in dim light over four 28-hour “days,” which inverted behavioral cycles by 12 hours by the fourth day — effectively simulating night work and causing circadian misalignment.
Participants were randomly assigned to one of two meal schedules. The Daytime-and-Nighttime Meal Control Group followed a 28-hour meal cycle that included eating during both daytime and nighttime hours, mimicking typical night-shift eating patterns. The Daytime-Only Meal Intervention Group followed a 24-hour meal cycle and ate only during daytime hours.
Mood was assessed hourly throughout the laboratory protocol. The results showed a clear effect of meal timing: during the simulated night shift, the Daytime-and-Nighttime group experienced significant increases in depression- and anxiety-like mood relative to baseline measurements taken during simulated day work. The Daytime-Only group did not show these adverse changes in mood.
The study also found that the greater a participant’s internal circadian misalignment, the higher their depression- and anxiety-like mood scores during the simulated night work condition, indicating that misalignment itself contributes to mood vulnerability.
“The timing of eating is emerging as an important dimension of nutrition that affects physical health, and our study suggests it may also play a causal role in mood and emotional well-being when circadian rhythms are disrupted,” Chellappa said. She emphasized that further clinical trials are needed to confirm whether shifting meal times can benefit people with depressive or anxiety-related disorders.
Disclosures: Frank Scheer has served on the Board of Directors for the Sleep Research Society and has received consulting fees from the University of Alabama at Birmingham.
Funding: This research was supported by the National Institutes of Health (grant numbers include R01HL118601, R01DK099512, R01DK102696, R01DK105072, R01HL140574, R01HL153969, K99HL148500 and UL1TR awards), the Alexander von Humboldt Foundation, and the American Diabetes Association.
About this diet and mental health research news
Author: Jessica Pastore
Source: Brigham and Women’s Hospital
Contact: Jessica Pastore – Brigham and Women’s Hospital
Image: The image is in the public domain
Original Research: Open access. “Daytime eating prevents mood vulnerability in night work” by Frank A. J. L. Scheer et al., published in PNAS.
Abstract
Daytime eating prevents mood vulnerability in night work
Shift workers face a 25–40% higher risk of depression and anxiety, partly because misalignment between the central circadian clock and daily behaviors can negatively affect mood. To identify evidence-based interventions that reduce mood vulnerability in shift work, the investigators used a rigorously controlled 14-day circadian protocol and compared mood during simulated night work under two meal-timing conditions: daytime-and-nighttime eating versus daytime-only eating, using simulated day work as baseline.
Simulated night work combined with daytime-and-nighttime eating increased depression-like mood by 26.2% (statistically significant) and anxiety-like mood by 16.1% relative to baseline, while simulated night work with daytime-only eating did not produce these increases. Larger degrees of internal circadian misalignment were strongly associated with greater depression- and anxiety-like mood during simulated night work. These results provide a proof-of-concept that an evidence-based meal timing intervention may prevent mood vulnerability when circadian rhythms are disrupted. Further research is needed to test whether changing mealtime patterns can protect actual night workers from increased mood risk.