People who consider themselves early risers are more likely to have a healthy diet.
And, conversely, individuals whose energy spikes later in the day are more predisposed to eating higher levels of sugars and fats.
That's because, according to researchers, the timing of our body clocks plays a substantial role in how eating habits are determined throughout the day.
The study, published in academic journal Obesity, analysed the diets of 1854 Finnish men and women aged 25 to 74.
During weekdays, night owls ate less for breakfast but still managed to eat more sugar, carbohydrates and saturated fat than their early-morning peers.
But, by the evening, they were also eating more sugars and fats.
By Saturday and Sunday, they not only ate less healthily but they also indulged in irregular meal times, often, very late-night eating.
They were more prone to snacking on sugar and fat-rich items.
This, the study's authors claimed, put them at higher risk of obesity and metabolic disturbances in the future.
In addition, they also suffered poorer sleep and were less physically active.
"Evening types are more prone to live against their internal biological time," lead author Mirkka Maukonen told the New York Times. "Our society is pretty much structured to suit morning types better."
However, she added that adapting is possible.
"[Our body clocks are] influenced half by genes and half by environment. Also, awareness of one's own chronotype may encourage paying more attention to overall healthier lifestyle choices.
"Also, awareness of one's own chronotype may encourage paying more attention to overall healthier lifestyle choices."