A recent study has revealed that irregular eating habits, such as frequently skipping breakfast or having late meals, can not only negatively impact physical health but also increase the risk of depression. Given that depressive symptoms are intertwined with overall daily rhythms beyond just emotional issues, experts suggest that dietary habits can play a crucial role in managing mental health.
Professor Tae Hye-jin from the Catholic University of Korea’s Seoul St. Mary’s Hospital’s Lifelong Health Promotion Center (Department of Psychiatry), along with Professor Chae Jeong-ho, recently published a study in the Journal of Affective Disorders. Based on data from 21,568 Korean adults, their research confirmed that both what we eat and how we eat – specifically, the regularity and diversity of meal patterns – are key factors in mental health.
Depression is recognized as one of the leading causes of disability worldwide, prompting increasing social interest in its prevention and management. The World Health Organization (WHO) reports that approximately 3.8% of the global population, or about 280 million people, suffer from depression. The annual productivity losses due to depression and anxiety disorders are estimated at around 1 trillion USD globally.
The research team analyzed data from 21,568 Korean adults using the National Health and Nutrition Survey, conducted by the Korea Centers for Disease Control and Prevention, spanning from 2014 to 2022. They assessed depressive symptoms using the Patient Health Questionnaire (PHQ-9) and applied statistical techniques, including multivariable logistic regression analysis, to systematically examine the association between irregular meal frequency and depressive symptoms.
The findings showed that adults with irregular main meals were about 1.55 times more likely to experience depressive symptoms compared to those with regular meals. This association remained significant even after adjusting for various factors such as income, education, smoking, drinking, exercise, and pre-existing conditions. Among the participants, 5.2% (1,131 individuals) exhibited clinically significant depressive symptoms. This group showed higher frequencies of irregular meals and breakfast skipping.
The researchers calculated a Dietary Diversity Score based on the intake of six food groups: grains, vegetables, fruits, meats, legumes and nuts, and dairy products. They found that a more varied diet mitigated the negative impact of irregular meals on depression. Conversely, the group with low dietary diversity showed the strongest effects from irregular meals.
Notably, the association between irregular meals and depressive symptoms was even stronger among those who frequently skipped breakfast. While the risk from irregular meals remained significant even for those who didn’t skip breakfast, it was relatively lower in intensity. The research team attributed this to breakfast’s role in stabilizing the day’s metabolic rhythm and the secretion of serotonin (the happiness hormone) and cortisol (the stress hormone), which support emotional regulation.
Sub-analysis based on gender, smoking status, and late-night eating habits revealed that the impact of irregular meals on depression was more pronounced among men, smokers, and adults with late-night eating habits. These findings suggest the need for more targeted dietary interventions for specific groups. This research, which explores not only what we eat but also when we eat, is expected to lay the groundwork for mental health interventions based on chrononutrition – the study of how meal timing affects health and metabolism.
Professor Tae emphasized that the study significantly demonstrates, using representative large-scale data, that both what we eat and how regularly we eat are crucial for preventing depression. The three principles of regular meals, preventing breakfast skipping, and consuming a variety of food groups can serve as immediate, medication-free strategies for depression prevention that anyone can implement in their daily life.
Meanwhile, according to the 2024 National Health and Nutrition Survey results from the Korea Centers for Disease Control and Prevention, about 34.6% of Koreans skip breakfast. The survey found that younger age groups have higher rates of breakfast skipping, with over 40% of teenagers and 57.2% of those in their twenties reporting that they skip breakfast. In light of these findings, experts stress the importance of developing healthy habits, such as regular breakfast consumption, for managing both physical and mental health.
