New research indicates that night owls may face a higher risk of obesity and slower metabolism, largely due to the tendency to consume a significant portion of their daily calories late at night. This study, conducted among women of European and Pacific descent in New Zealand, sheds light on these dietary habits.
Research by van der Merwe et al. explores the relationship between chronotypes, dietary intake, meal timing, body composition, and metabolic biomarkers in healthy New Zealand women of European and Pacific descent. Image credit: RitaE.
Individuals structure their sleep and wake cycles based on personal preferences, aligning their activities with the natural light-dark cycle, a concept known as chronotype.
Your chronotype dictates not only your sleep schedule but also influences your meal timing and eating habits.
For instance, early risers, or morning chronotypes, typically go to bed and wake up several hours earlier than night owls, who prefer to stay up late and wake up later.
As explained by Professor Roseanne Kruger from Massey University and Griffith University, “Chronotype influences our food intake preferences, behavior, and metabolism.”
The study involved 287 healthy women of European and Pacific Islander descent in New Zealand. Participants provided information about their sleep patterns via questionnaires, maintained a 5-day food diary, underwent body composition scans, and provided fasting blood samples for metabolic testing.
Results revealed that over half of the participants identified as intermediate chronotypes, while 34% were night owls and 12% were morning owls. The average BMI of night owls was 31.4 compared to 26.1 for morning and intermediate chronotypes combined.
Night owls exhibited a higher body fat percentage and a greater android-to-gynoid fat ratio, indicating higher abdominal fat accumulation.
While total daily food intake was relatively similar, meal timing showed significant differences. Morning and intermediate types consumed more energy-rich nutrients before 10 a.m., whereas night owls typically ate more after 8 p.m.
This trend was particularly evident among women with higher body fat percentages, who ate less in the morning and significantly more late at night.
Compared to morning chronotypes, night owls had lower intakes of several nutrients linked to a balanced diet, including fiber, vitamins A and E, folate, calcium, magnesium, potassium, and iodine.
Blood tests indicated poorer metabolic health among evening chronotypes, showing elevated triglycerides, insulin, glycated hemoglobin, and leptin levels, alongside reduced HDL (“good”) cholesterol and ghrelin, the appetite hormone.
Correlation analyses indicated that increased morning energy intake was associated with higher HDL cholesterol and lower levels of insulin and glycated hemoglobin, while increased evening energy intake linked to higher triglycerides and insulin levels.
“Healthy women in New Zealand, whether morning or night owls, consumed similar amounts of food throughout the day,” the study confirmed.
However, night owls had lower intake between 3 a.m. and 9:59 a.m. and higher intake between 8 p.m. and 2:59 a.m., a dietary pattern linked to increased body fat percentages and unfavorable metabolic markers.
“Eating during nighttime hours, when your body is typically in a fasting state, tends to promote fat storage rather than energy use, contributing to obesity and negative health impacts,” the researchers noted.
For more details, refer to the study published in the Journal on July 7, 2026, in the Frontiers of Nutrition.
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Karlian van der Merwe et al. (2026). Associations between chronotype and dietary intake, meal timing, body composition, and metabolic biomarkers. Frontiers of Nutrition 13; doi: 10.3389/fnut.2026.1862060
Source: www.sci.news