Is any breakfast better than none? Not really — quality is what counts.
The common saying "breakfast is the most important meal of the day" is too simple. What you eat matters as much as whether you eat. A 2024 study of 648 Australian high school students found that simply eating breakfast predicted higher adaptive motivation (like focus and persistence), but the quality of that breakfast was crucial: a high-quality breakfast (rich in vegetables, fruit, dairy, protein, whole grains, and water, and low in sugary drinks, processed meat, and unhealthy snacks) was linked to the highest levels of adaptive motivation and achievement later that day [1]. In contrast, a low-quality breakfast was associated with more maladaptive motivation (like anxiety and self-doubt) [1].
Similarly, a 2025 study of over 23,000 U.S. adults found that people who ate a high-quality breakfast had 28% lower odds of depression symptoms compared to those with the lowest-quality breakfast [2]. The takeaway: a sugary donut or a fast-food sandwich is not the same as a balanced meal. The "most important" label only holds true when the meal is nutritious.
When you eat breakfast also affects your mood and mental health.
It's not just what you eat, but when. The same 2025 study on U.S. adults found that eating breakfast after 9:00 AM was associated with a 28% higher risk of depression symptoms compared to eating before 8:00 AM [2]. Eating between 8:00 and 9:00 AM showed a smaller, non-significant increase [2]. This suggests that a later breakfast may disrupt your body's internal clock (circadian rhythm), which is linked to mood regulation.
This timing effect is echoed in research on Japanese workers: those who ate a traditional Japanese breakfast (rice, fish, vegetables) tended to have an earlier chronotype (they were "morning people") and were more physically active in the early morning [5]. In contrast, those who ate cereal or skipped breakfast had a later chronotype [3][5]. So eating a healthy breakfast early may help align your daily rhythm with better mental and physical health.
The benefits (and risks) are strongest for children and adolescents.
Young people seem to be especially sensitive to breakfast habits. A massive study of over 115,000 Chinese adolescents followed from age 11 to 18 found that skipping breakfast was prospectively associated with a wide range of emotional and behavioral problems, including anxiety, depression, attention problems, and aggressive behaviors [4]. The odds were 1.34 to 2.29 times higher for those who skipped breakfast compared to those who ate at home [4]. Importantly, these associations were stronger in younger students and in those with lower body weight, suggesting that younger and underweight children are most vulnerable [4].
The same study also found that eating breakfast away from home (e.g., at a fast-food restaurant) was linked to higher risks, though less severe than skipping entirely [4]. This reinforces the idea that a nutritious breakfast eaten in a stable environment (like home) is especially important for developing minds and bodies.
Sources used in this answer
A healthy breakfast each and every day is important for students' motivation and achievement
Among 648 Australian high school students, eating a high-quality breakfast (rich in vegetables, fruit, dairy, protein, whole grains) was associated with the highest levels of adaptive motivation and achievement later that day, while low-quality breakfast was linked to more maladaptive motivation [1].
Associations of breakfast habits and breakfast quality with depression symptoms: A cross-sectional study based on NHANES 2007–2018
In 23,839 U.S. adults, skipping breakfast was associated with 23-26% higher odds of depression symptoms, and eating breakfast after 9:00 AM was linked to 28% higher odds compared to eating before 8:00 AM [2].
Association of Japanese Breakfast Intake with Macro- and Micronutrients and Morning Chronotype
Among 2,671 Japanese adults, a Japanese-style breakfast (rice, fish, vegetables) was associated with an earlier chronotype (morning preference) and higher intake of protein, fat, and key micronutrients like vitamin K, compared to cereal or skipping breakfast [3].
Skipping Breakfast and Eating Breakfast Away From Home Were Prospectively Associated With Emotional and Behavioral Problems in 115,217 Chinese Adolescents
In 115,217 Chinese adolescents followed over 6 years, skipping breakfast was prospectively associated with 1.34 to 2.29 times higher odds of emotional and behavioral problems (e.g., anxiety, attention problems, aggression), with stronger effects in younger and underweight students [4].
Association between Breakfast Meal Categories and Timing of Physical Activity of Japanese Workers
Among 3,395 Japanese workers, those who ate a Japanese breakfast had an earlier chronotype and were more likely to be physically active between 6:00-9:00 AM, compared to those who ate cereal or skipped breakfast [5].