A domestic study has found that people who frequently skip meals or have irregular meal times face a higher risk of experiencing depressive symptoms. However, eating a wide variety of foods in a balanced way appears to partially mitigate this association.

The research team led by Professors Tae Hye-jin (Department of Family Medicine, Health Promotion) and Chae Jung-ho (Department of Psychiatry) at Seoul St. Mary’s Hospital published these findings in the international journal Journal of Affective Disorders.

Depression is a major mental disorder that affects approximately 280 million people worldwide. Until now, mental health experts have mainly focused on factors such as genetic predisposition, changes in neurotransmitters in the brain, and stress. Recently, however, attention has been growing toward everyday behavioral factors such as dietary habits and daily rhythms.

In particular, meal timing plays an important role in regulating the body’s internal clock, the “circadian rhythm.” This rhythm controls sleep patterns, hormone secretion, and metabolism.

The researchers explained that irregular meal times can affect the rhythm of hormone secretion, such as cortisol, and the gut microbiome environment. Such circadian disruption may negatively influence mood regulation and brain function by deteriorating sleep quality and increasing systemic inflammation.

This study analyzed data from 21,568 Korean adults who participated in the Korea National Health and Nutrition Examination Survey between 2014 and 2022.

Participants reported how many times per week they had eaten breakfast, lunch, and dinner over the past year. The research team classified any meal eaten fewer than five times per week as an “irregular meal.”

They also assessed how diversely participants consumed six food groups—grains, vegetables, fruits, meat, legumes, nuts, and dairy products—to calculate a “dietary diversity score.”

Depressive symptoms were evaluated using a survey instrument widely used internationally. Participants answered how often they had experienced lethargy, hopelessness, and sleep changes during the previous two weeks.

Analysis showed that 5.2% of participants had clinically significant levels of depressive symptoms. These individuals tended to have lower household income and educational attainment, were more often unmarried, had lower adherence to aerobic and strength exercise, and also had a higher frequency of irregular meals.

Those with the most irregular meal times had approximately 1.55 times higher risk of experiencing depressive symptoms than those with the most regular meal patterns. The more irregular the meal pattern, the higher the risk of depressed mood tended to be.

This association was particularly strong among those with low dietary diversity, meaning those who did not consume a balanced variety of different food groups.

The researchers explained that a dietary habit of eating a wide variety of foods in a balanced manner can help maintain stable intake of vitamins and anti-inflammatory nutrients and promote a healthy gut microbiome environment. These factors may, in turn, positively influence brain function and emotion regulation.

By contrast, the association with depressive symptoms was even stronger among those who frequently skipped breakfast.
The research team stated that skipping breakfast can delay the start of metabolic activity and increase blood glucose fluctuations, which may affect morning hormone rhythms involved in emotion regulation and cognitive function.

Depression-related scores were worst among those who frequently skipped breakfast and also had low dietary diversity.

In addition, the association between irregular meals and depressive symptoms was more pronounced among men, smokers, and people who frequently ate after 9 p.m.

First author Professor Tae Hye-jin said, “This study is meaningful in that it has demonstrated with large, representative data that, for depression prevention, not only what is eaten but also how regularly it is eaten is important,” adding, “The three principles of regular meals, preventing breakfast skipping, and consuming a variety of food groups can serve as depression-prevention strategies that can be implemented immediately in daily life even without pharmacological treatment.”

However, the research team cautioned that these findings should not be directly interpreted as applicable to the “16:8 time-restricted eating” regimen (the most common form of intermittent fasting), which has become popular worldwide in recent years.

When asked whether intermittent fasting that involves skipping breakfast could itself adversely affect mental health, corresponding author Professor Chae Jung-ho responded in writing to Donga.com, “In this study, the most important independent risk factor was the regularity of meal rhythm, but due to the study design, we were not able to distinguish ‘intentional eating routines’ from simple meal irregularity.”

According to the research team, the presence of breakfast skipping and the amount of nutrient intake in this study were evaluated using the “24-hour recall method,” in which participants recall and report what they consumed during the previous day. Therefore, individuals who intentionally did not eat breakfast because of intermittent fasting would still have been categorized in the data simply as “breakfast skippers.”

Furthermore, meal irregularity was scored based on how many of breakfast, lunch, and dinner had been eaten fewer than five times per week over the past year. For example, a person who did not eat breakfast every day to practice 16:8 intermittent fasting could receive a high “irregular meal” score in the dataset, even if that person maintained a consistent routine. In other words, this study alone cannot clearly distinguish regular time-restricted eating from simple meal irregularity.

Professor Chae stated, “Special lifestyle patterns such as night-shift work or intermittent fasting may not have been sufficiently differentiated in this study,” and added, “Separate research is needed to determine what relationship intermittent fasting itself may have with the risk of depression.”

The research team emphasized that these findings do not prove causality.

Because this was an observational study analyzing conditions at a specific point in time, it cannot be concluded definitively that the habit of skipping meals actually causes depression. It is also possible that individuals experiencing depressed mood skipped meals or consumed monotonous diets due to loss of appetite and lethargy.

Another limitation was that dietary information relied on self-reporting by participants and did not fully account for factors such as stress levels or sleep quality, which may influence depressive symptoms.

Related paper link: https://doi.org/10.1016/j.jad.2026.121417

Popular News