Less Calories Are Burned and Hunger Is Increased by Eating Late

A study has revealed that when we eat has a significant influence on appetite, energy expenditure, and adipose tissue molecular pathways.¹✅ JOURNAL REFERENCE
DOI: 10.1016/j.cmet.2022.09.007

The researchers wished to examine the mechanisms that could explain why the risk of obesity increases by eating late. Prior studies have demonstrated that eating late is linked to an increase in body fat, increased risk of obesity, and weight loss impairment.

The researchers discovered that eating 4 hours later makes a substantial difference to the way fat is stored, hunger levels, and the way calories are burnt after eating.

The researchers studied 16 individuals with a BMI in the obese or overweight range. Each individual participated in 2 laboratory protocols: 1 with a strict early meal schedule, and another scheduled approximately 4 hours later in the day, each with identical meals.

Sleep and wake schedules were fixed In the last 2 to 3 weeks before starting each of the protocols, and they strictly adhered to the same meal schedules and diets at home in the final 3 days before going into the laboratory. The individuals regularly recorded their appetite and hunger In the laboratory, providing regular small blood samples during the day, and energy expenditure and body temperature was measured.

To measure how the time of eating influenced how the body stores fat, or molecular pathways associated with adipogenesis, adipose tissue biopsies were collected from a subset of individuals during laboratory testing in the early as well as late eating protocols, making it possible to compare gene expression levels/patterns between these 2 eating protocols.

Results showed that later eating had significantly affected ghrelin and leptin, the hormones that regulate appetite and hunger. Levels of the satiety-signaling leptin hormone were particularly reduced over the 24 hours in the eating late protocol in comparison to the early eating protocols.

When individuals ate later, calories were also burned at a slower rate and adipose tissue gene expression was exhibited towards decreased lipolysis and increased adipogenesis, which promotes fat growth. These results suggest converging molecular and physiological mechanisms underlying the connection between eating late and the increased risk of obesity.

These results aren’t only in line with a large body of research indicating that eating later can increase the probability of developing obesity, but they explain how this can take place. By making use of a randomized crossover study, and tightly controlling for environmental and behavioral factors which include light exposure, sleep, posture, and physical activity, the researchers were able to detect changes in the different control systems associated with energy balance, a marker of how our bodies make use of the food we eat.