Dietitians analyzed eating habits and body mass index (BMI) in 7,074 people aged 40–65 and found that early breakfasts and early dinners combined with a longer overnight fasting window produced lasting .
Epidemiologist Luciana Pons-Muzzo (ISGlobal) says: “Our results, consistent with other recent studies, suggest that extending overnight fasting can help maintain a healthy weight when dinner and breakfast are early.” Researchers link that to circadian rhythms — the internal biological clock that signals the body when to rest and when to be active.
Eating earlier in the day better aligns with these rhythms, which helps the body burn calories more efficiently and regulate appetite, ultimately helping maintain a healthy weight.
The ISGlobal team’s main observations about how meal timing affects health:
- a later breakfast time and more frequent eating were associated with higher BMI;
- a longer nightly fasting period (that is, an extended overnight fast) was associated with lower BMI;
- these associations were especially noticeable in premenopausal women.
Simple study, clear takeaways
The team used several statistical methods and adjusted results for age, sleep, and other variables. They also ran a cluster analysis to group participants by typical eating patterns — that helped separate expected patterns and reveal differences between men and women.
In one cluster, found mainly in men, the first meal occurred after 2 p.m. People in that group fasted overnight for an average of 17 hours, drank alcohol more often, and smoked. That kind of intermittent fasting — skipping breakfast — did not lead to weight loss.
If you are skipping breakfast to cut calories, shift dinner earlier and eat breakfast.
Adequate nighttime rest matters for health, and combining sleep and eating schedules may be the key.
Chrononutrition: why when you eat might matter as much as what you eat
Epidemiologist Anna Palomar-Cros (ISGlobal) says the study is part of a new field called “chrononutrition,” which looks not just at what we eat but at when and how often we eat. The field is built on the idea that unusual eating patterns can conflict with the circadian system and disrupt physiological cycles that should follow the day–night rhythm.
The work was published in the journal International Journal of Behavioral Nutrition and Physical Activity.
Based on reporting from ScienceAlert
Photo: Unsplash
