Sleep is often discussed alongside diet and exercise when it comes to health. New research suggests it may also shape how and when teens eat.
A study published in Sleep Health found that adolescents who went to bed later and woke up later consumed more calories, snacked more frequently and were more sedentary than those with earlier sleep schedules. The findings suggest that sleep timing, not just sleep duration, may be linked to eating patterns and activity levels.
The study included 373 participants from the Penn State Child Cohort, with an average age of 16. Researchers tracked multiple aspects of sleep using wearable devices, sleep studies and self-reported data, along with dietary intake and physical activity.
Teens with later sleep schedules tended to skip breakfast and eat more later in the day, often replacing a morning meal with lunch, dinner and late-night snacks. Their diets were higher in total calories and carbohydrates, and they were less physically active overall.
“Sleep timing — when teens go to bed and wake up — had the biggest influence on sedentary and eating behavior in teens,” said Julio Fernandez-Mendoza, professor of psychiatry and behavioral health at Penn State College of Medicine.
Irregular sleep patterns were also linked to less healthy behaviors. Teens who alternated between shorter and longer nights of sleep tended to be less active, suggesting that consistency may play a role alongside timing.
The relationship between sleep and behavior appeared to be stronger during the school year. When teens were required to follow early schedules that conflicted with their natural sleep rhythms, the effects on eating and activity patterns were more pronounced. During school breaks, when schedules were more flexible, those relationships weakened, though snacking increased.
The findings add to a growing body of research showing that sleep, diet and physical activity are closely connected. Rather than operating independently, these behaviors may influence one another in ways that affect long-term health.
“Sleep is more than just how long a person sleeps,” said Pura Ballester-Navarro, a co-author of the study. “We have to think about it from a more holistic perspective.”
Because the study was observational, it cannot show that later sleep schedules directly cause changes in diet or activity. However, the results suggest that when sleep patterns shift later or become more irregular, eating habits may shift as well.
This research was supported by the National Institutes of Health and the Fundación Seneca-Science and Technology Agency of Murcia.