A report published in the International Journal of Obesity has examined changes in our desire to overeat which take place throughout the day. The study, piloted by Johns Hopkins University of Medicine in Baltimore, also took into account participants’ stress levels.
The idea was to demonstrate how a person’s mental state can impact their hunger hormones. Experiments were carried out on a group of 19 men and 13 women aged 18 to 50, who were overweight. Their body mass indexes were between 28 and 52 – people are considered overweight from 25 and upwards.
In the first part of the experiment, each participant had to fast for 8 hours before consuming a liquid containing 608 calories at 9am or 4pm. Around 130 minutes after the meal, participants’ stress was measured using a camera which recorded their facial expressions. Researchers also analyzed their blood to estimate their stress and hunger hormone levels.
Our desire to eat depends on the time of day
Thirty minutes after the stress test, participants were offered a buffet meal comprising pizza, snack biscuits, biscuits and chocolate sweets. By observing participants’ behavior, the research team noticed that appetite tended to be stronger in the evening compared to the morning, sensations of fullness diminished in the evening and this trend was reinforced by stress.
"The good news is that this knowledge will allow people to take steps to reduce their risk of overeating in the evening, by eating earlier in the day or by finding other ways to compensate for stress", stated Sarah Carnell, Adjunct Professor of Psychiatry and Behavioral Sciences at Johns Hopkins University of Medicine, as reported in The Independent.