'Night Owls' At Risk Of Wider Waistlines, Unhealthy Hearts

THURSDAY, July 16, 2026 (HealthDay News) — Higher levels of cholesterol and body fat are more likely in folks who stay up late, new research finds.

The study of 287 women in New Zealand found that "early birds" and "night owls" ate about the same amount of food each day, but it was the timing of their eating that mattered.

“The research highlights that when people eat may be just as important as what they eat,” said study senior author Rozanne Kruger, a professor and nutrition researcher at Griffith University in Brisbane, Australia. “Targeting meal timing, particularly reducing late-night eating, could be an important strategy for improving health amongst people with an evening chronotype."

Chronotypes define the daily sleep/wake patterns of people — such as the early bird or night owl.

The study participants were all women between the ages of 18 and 45, and Kruger's team tracked their individual chronotypes, overall health and eating patterns.

Folks who went to bed later had unhealthier eating patterns, the researchers found. Compared to early risers, the night owls ate relatively less food overall in the morning (before 10 a.m.) but concentrated their intake of energy-rich foods during the evening and nighttime (between 8 p.m. and 3 a.m.). 

The opposite pattern was true for the folks who were "early to bed, early to rise," the team found.

As Kruger and her colleagues explained, eating at night (when ideally people should be sleeping) is tougher on the body. When confronted with energy-rich food at night, the body stores it as fat rather than burning it off. 

So, it came as no surprise that night owls in the study were more likely to have a greater percentage of body fat than the early birds, as well as larger volumes of belly fat.  

Fans of late-night eating also tended to have higher levels of blood fats such as cholesterol, the team found.

Blood sugar regulation was also poorer among the night owl women compared to their early-bird peers.

“Chronotypes influence our preferences for food intake, our behaviors and our metabolism,” Kruger said in a news release. “Both morning-types and evening-types consumed similar amounts of food or energy across the day, but it was the timing of eating that was crucial.”

The findings were recently published in Frontiers in Nutrition.

More information

There's more on the timing of meals and weight control at Harvard Health.

SOURCE: Griffith University, news release, July 13, 2026