How does dinner time affect health? Research points to early and light meals

When it comes to healthy eating, the content of the plate is often the main topic of discussion. However, the field of "chrononutrition," which has gained prominence in recent years, shows that meal times can also be a determining factor for metabolism, appetite, weight control, and cardiovascular health.

According to this approach, the body's internal clock, or circadian rhythm, is closely linked to processes such as hunger, digestion, hormone release, and blood sugar regulation. For this reason, consuming the same food at different times of the day can lead to different results in the body.

Observations made by Marta Garaulet at the University of Murcia in Spain at a weight-loss clinic became one of the notable examples of research on meal timing. Garaulet began investigating this topic after noticing that among two patients following the same diet, the one who ate lunch earlier lost more weight.

Garaulet and her team monitored 420 adults in Spain participating in the same weight-loss program for 20 weeks. The findings revealed that those who ate lunch earlier lost weight faster and in greater amounts compared to those who ate later in the day.

BODY CLOCK AND BLOOD SUGAR

Frank Scheer, a professor of neuroscience at Brigham and Women’s Hospital in Boston, explains this difference through the body's biological changes throughout the day. In Scheer's words, "Biologically, we are not the same person in the morning as we are in the evening."

Eating while the body is preparing for sleep can lead to an imbalance that experts define as "circadian misalignment." This situation becomes particularly evident in blood sugar control. In a 2022 study involving more than 800 adults, it was observed that participants processed glucose consumed one hour before bedtime less efficiently than glucose consumed four hours before bedtime.

In the study, blood sugar levels remained higher following carbohydrates consumed closer to bedtime, while the insulin response that regulates blood sugar was weaker. Researchers believe that the melatonin hormone, which rises in the evening hours, plays an important role in this process.

The effect of eating late is not limited to blood sugar. Studies show that late meals can affect appetite and satiety hormones, leading to a greater feeling of hunger the next day. The lower secretion of the leptin hormone, which signals satiety, stands out as one of these mechanisms.

In another study examining approximately 1,200 adults, it was reported that in individuals with genetic traits associated with a high risk of obesity, eating late was linked to a higher body mass index, and that eating earlier could reduce this risk.

HEART HEALTH AND DAILY ROUTINE

Meal times may also be important for heart health. In a study conducted in France with more than 100,000 people, it was observed that the risk of cardiovascular disease was higher in those who ate breakfast later. In the same study, it was stated that extending the nighttime fasting period by eating dinner earlier was associated with better heart health.

Experts emphasize that these findings may be particularly important for groups whose circadian rhythms are frequently disrupted, such as shift workers. However, prolonged fasting may not be safe or feasible for everyone who works at night. For this reason, personal health status, work schedule, and energy needs should be taken into account.

Chronotype is also among the factors that affect meal times. The nutritional habits and the body's response to nutrients can differ between people who are active early in the morning and those who stay awake until late hours. Giovanna Muscogiuri from the University of Naples Federico II states that night owls may tend to delay meals and gravitate toward more energy-dense foods later in the day.

So, what can be done in practice? Research does not suggest a single "perfect time." However, the general picture indicates that moving the larger meal of the day to earlier hours and finishing dinner at least three hours before bedtime may be more appropriate for metabolism.

The recommendation from experts is to establish regular meal times; consume fibrous carbohydrates such as whole grains, legumes, and fruits earlier in the day; and prefer lighter and protein-balanced meals in the evening. Since insomnia can increase feelings of hunger and the tendency toward high-calorie foods, sleep quality is as important as dietary habits.