Delaying or skipping breakfast is associated with a higher likelihood of mood disorder among adults, according to a new study published in the journal Psychological Medicine.

“Mood disorders such as depression can have a big impact on individuals, their friends and family, and broader society. It is important to consider different factors that could contribute to mental disorders, to identify ways to prevent or treat ill health,” said study author Johanna Wilson, a PhD candidate at the University of Tasmania.

“Research has shown that a healthy diet is linked to a lower risk of depression. We were interested to know if when people ate during the day was linked to a higher or lower risk of having depression.”

The researchers analysed data from the Australian Childhood Determinants of Adult Health (CDAH) study, which started in 1985 when the participants were between 7 and 15 years old.

As part of the longitudinal study, more than 1,000 participants reported at what times they had eaten the previous day when they were 26-36 years old, and again five years later when they were 31-41 years old. The participants also completed an assessment of mood disorders, such as depression, dysthymia, and bipolar disorder.

The researchers found that those who indicated that they had skipped or delayed breakfast were more likely to experience a mood disorder compared to those with a more conventional eating schedule of breakfast, lunch and dinner.

“Our study highlights that when you eat may be important for your health, not just what and how much you eat. We found that people who tended to skip or delay breakfast and consume a larger proportion of their daily food intake later in the day were more likely to have a mood disorder,” Wilson told PsyPost.

“This may be due to hormonal and circadian effects of eating at a certain time, but it could also be due to whether someone is a morning or evening type person, known as chronotype.”

The findings are in line with a previous study, which found that breakfast skippers were at greater risk of depression than those who ate breakfast.

Of course, just because someone skips breakfast doesn’t mean they’re necessarily going to develop a mood disorder. “As with many epidemiological studies, the results are more generalisable to a population rather than to individuals,” Wilson said.

It is also unclear if skipping breakfast increases the risk of mood disorders or if mood disorders increase the likelihood of skipping breakfast. “These relationships may be bidirectional, and a pre-existing preference for certain eating patterns due to chronobiological traits of the individual should be considered,” the researchers explained.

“There is a limit on the number of things we can measure and these unmeasured factors could explain the associations that we observed. Future studies that identify things like chronotype traits could be useful in determining the influence of time-of-day eating on mood disorders,” Wilson added.

The study, “An eating pattern characterised by skipped or delayed breakfast is associated with mood disorders among an Australian adult cohort“, was authored by J. E. Wilson, L. Blizzard, S. L. Gall, C. G. Magnussen, W. H. Oddy, T. Dwyer, K. Sanderson, A. J. Venn and K. J. Smith.