Geschatte leestijd: 3 minutenBinge eating, who doesn’t know them? New research provides additional evidence that levels of ‘hunger hormones’ rise in the evening while ‘satiety hormones’ decrease. Stress appears to increase hunger hormones in the evening, and especially the appetite of binge eaters seems to be strongly influenced by these hormones.
Hunger and Love
These are the conclusions of researchers from Johns Hopkins University conducted among a small group of overweight individuals. Last month, the results were published in the International Journal of Obesity.
The research is intended to help people gain more control over unhealthy eating patterns, including giving in to binge eating. The study shows that evenings pose a high risk of overeating, especially when you are stressed and already susceptible to binge eating. In the wonderfully simple world of science, this provides tools to monitor your weight. Armed with this knowledge, one can choose to eat earlier in the day or find ways to relieve stress, according to the researchers. Simple.
So, as can be inferred from the chosen words, I am a bit skeptical that such insight makes it much easier in practice. Nevertheless, it is certainly an interesting fact what happens in that little head when suddenly you would commit a murder for a cream puff, or two. Knowing where a certain feeling comes from may make it easier to rationally decide how to deal with it.
In love, for example, it can work the same way. Adults can suddenly behave like schoolchildren when certain hormones and neurons come into play and make them think they have found ‘the one.’ Where you think your interest in someone is a sum of several attractive qualities, it is often primarily a sum of testosterone, adrenaline, dopamine, serotonin, oxytocin, and vasopressin. Just as such substances can make you think you really need to be with someone, hormones can make your body think it really needs certain food.
Indulging in binge eating is much easier when your body tells you it craves a double cream puff and makes you feel like you’re doing well when you walk to the refrigerator.
Hunger, Stress, and Binge Eating
The researchers at Johns Hopkins University base their work on previous studies that showed the ‘hunger hormone’ ghrelin can rise under the influence of stress during the day. Because they were curious about what this did to feelings of hunger in the evening, they decided to set up an experiment to measure hunger and stress hormone at different times.
Nineteen men and thirteen women with overweight, aged between 18 and 50, participated in the study. Half of the participants had previously been diagnosed with binge eating disorder. Except for a BMI between 28 and 52, the participants were healthy.
For the experiment, the participants had to fast for 8 hours first, then they received a liquid meal of 608 kcal at 09:00 or 16:00. Approximately 130 minutes after the meal, each participant underwent a standard stress test. A camera captured their facial expressions while their (non-dominant) hand was kept in cold water for 2 minutes. Blood was drawn to measure stress and hunger hormones. In addition, participants were asked to score subjective hunger and satiety.
Thirty minutes after the start of the stress test, the participants were offered a buffet consisting of three medium pizzas, bags of chips, cookies, chocolate candy, and water.
The researchers observed that the time of day had a major influence on the (subjective) feeling of hunger, which was much higher in the evening than in the morning. They also found that relatively low levels of peptide YY, a hormone linked to decreased appetite, glucose, and insulin, when the liquid meal was consumed later in the day.
According to Susan Carnell, assistant professor of psychiatry and behavioral sciences at Johns Hopkins University, only the group with binge eating disorder had a lower feeling of satiety in the evening. This group also had higher levels of the hunger hormone ghrelin in the evening and lower levels of ghrelin in the morning, compared to those without this eating disorder.
After the stress test, stress levels peaked and hunger levels began to rise slowly in all participants, both in the morning and evening. However, ghrelin levels were higher in the evening, suggesting that stress has a greater impact on this hunger hormone in the evening than during the day.
Reference
- S Carnell, C Grillot, T Ungredda, S Ellis, N Mehta, J Holst, A Geliebter. Morning and afternoon appetite and gut hormone responses to meal and stress challenges in obese individuals with and without binge eating disorder. International Journal of Obesity, 2017; DOI: 10.1038/ijo.2017.307
