Why do we lose our appetite when the temperature rises?



Many people have experienced the feeling of not wanting to eat anything due to

summer fatigue . LiveScience, a science media outlet, explains the reasons why you lose your appetite during hot weather.

Why do you feel less hungry when it's hot out? | Live Science
https://www.livescience.com/health/why-do-you-feel-less-hungry-when-it-s-hot-out



According to Associate Professor Alison Childress of Texas Tech University, the effect of temperature on appetite has been the subject of research for many years. Previous research has shown that people in cold environments eat more food than others. Childress analyzes that the reason for this is that more energy is needed to maintain body temperature even in cold environments. However, the mechanism by which appetite decreases when the cold eases has

not been clarified until now.

'There are a variety of factors that influence why we feel hungry and why we feel less hungry on hot days, including hormones, proteins and environmental factors,' said Matt Carter of Williams College.



The human body has a characteristic called '

homeostasis ' that tries to keep the internal environment constant. When we are active in the sun, we sweat and our surface temperature drops. When we exercise intensely, we feel thirsty. When we have few calories in our body, we feel hungry and full after a meal. These are all considered to be part of homeostasis.

Many homeostatic processes are maintained by hormones that act as chemical messengers in the body. Appetite and satiety are regulated by hormones ghrelin , which is released when the stomach is empty, and leptin , which sends satiety signals to the brain when the stomach is full.

These hormones send signals to the hypothalamus in the brain, which regulates body temperature, hunger, thirst, etc. At the base of the hypothalamus is a cluster of specialized neurons that regulate hunger and satiety. Ghrelin stimulates hunger-related neurons, the AgRP neurons , which create hunger. In contrast, leptin stimulates the POMC neurons , which create satiety.

Previous research has shown that the brain contains a protein that changes shape when body temperature reaches a certain level. A 2020 study on mice found that when temperatures are low, this protein sends information to AgRP neurons to increase hunger. Meanwhile, a 2018 study found that when temperatures rise and body temperature rises, a heat-sensing protein activates POMC neurons to increase satiety.



'There is still room for investigation into how temperature affects complex systems in the body, and perhaps there are other factors that influence hunger and fullness beyond what we have found in our studies,' Carter said.

'Eating and drinking may seem like a coincidence, but in reality, your appetite is a complex balance of calories, fluids, and optimal body temperature, all of which are precisely measured by your brain,' Carter said.

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in Science,   Junk Food, Posted by log1r_ut