Researchers have found that in the evening, we experience alterations in the levels of hormones that influence appetite, which may cause us to overeat.
Unsurprisingly, stress and a predisposition to binge eat were also found to increase hunger levels in the evening. But there may be answer to this problem: eat earlier in the day.
The study — conducted by researchers from the Johns Hopkins School of Medicine in Baltimore, MD, and the Mount Sinai Icahn School of Medicine in New York City, NY — was recently published in the International Journal of Obesity.
The research included 32 adults, aged 18–50 years, who were overweight.
Around half of the participants had received a diagnosis of binge eating disorder, which is defined as episodes of uncontrollable eating that often lead to weight gain.
Each subject was asked to participate in two experiments. The first required the subjects to fast for 8 hours before receiving a "liquid meal," consisting of 608 calories, at 9 a.m.
For the second experiment, participants were again asked to fast for 8 hours, but this time, they consumed the liquid meal at 4 p.m.
Testing how time of day affects appetite
Around 130 minutes after each meal, the participants all underwent a stress test. This required the subjects to place one hand in a bucket of cold water for 2 minutes, while their facial expressions were recorded.
Participants were offered a food and drink buffet, which consisted of pizza, cookies, chips, candy, and water, 30 minutes after the stress test began.
The researchers also took blood samples from the subjects, and these were monitored for levels of the "stress hormone" cortisol, as well as the "hunger hormones" ghrelin and peptide YY (PYY).
