The One Surprising Side Effect of Feeling Hungry, Says Science
When you're really hungry for a snack, you may want to stay away from those online shopping sales. The hormone that tells your brain it's time to eat may also convince you it's time to spend money, suggests new research presented at the 2021 meeting of the Endocrine Society.
Higher levels of the hormone ghrelin, the so-called "hunger hormone," which stimulates appetite, predicts a greater desire for speedy monetary rewards even when delaying the payday results in receiving more money, according to a study at Massachusetts General Hospital and Harvard Medical School. The "time to eat" hormone may play a broader role than previously thought in human reward-related behavior and decision making, such as monetary choices, says, Franziska Plessow, PhD, assistant professor of medicine at Harvard and a co-investigator in the study. She notes that other recent research has linked ghrelin to impulsive choices and behaviors in rodents.
Ghrelin is produced primarily in your stomach, typically when it is empty. The hormone travels to the brain, to the part of the hypothalamus that controls appetite, triggering the desire to eat. Another hormone, leptin, signals your brain to regulate appetite. Higher levels of ghrelin may trigger a greater desire to keep eating. Research suggests that obese people may be particularly sensitive to ghrelin due to overly active receptors and result in greater food consumption. (Related: 15 Underrated Weight Loss Tips That Actually Work)
The study involved 84 females, ages 10 to 22. Thirty-four were healthy control participants while 50 had an eating disorder like anorexia nervosa. The researchers tested participants' blood for ghrelin levels before and after the subjects ate an identical meal. Following the meal, all participants took a test of financial choices. They were asked to choose a preference for a smaller immediate reward, say, $20 right now, or a larger delayed amount, $80 to be paid in 14 days.
The control group with higher ghrelin scores were more likely to choose the quick, but a smaller amount of money rather than delay gratification for two weeks to earn more money. That choice indicates more impulsivity, says Plessow.
By contrast, there was no apparent connection between ghrelin levels and monetary choices in the study participants with a low-weight eating disorder. A possible reason? People suffering from anorexia typically have ghrelin resistance, Plessow explains, and a lower desire to eat. The results in those subjects further suggest the broader way ghrelin may affect reward processing in the brain.
Gain the upper hand on your hunger—and maybe make better financial decisions—by munching on these 12 Best Snacks that Crush Hunger Cravings.