Young-Hwan Jo from the Albert Einstein College of Medicine in New York found that increased body temperature can curb your appetite.
After noticing he wasn't as hungry as usual after his 45-minute run, Jo set about analysing the brain's reaction to exercising. Jo and his team studied the part of the brain that contains "proopiomelanocortin" neutrons (POMCs), the section that co-ordinates appetite suppression.
Jo hypothesised that these POMCs might respond to changes in body temperature.
Initially, researchers experimented on mouse hypothalamus tissue that contained POMC brain cells. First, the team exposed the tissue to capsaicin, a compound found in chilli that interacts with sensory receptors, and then to heat to see if both would trigger the POMC cells.
Previous research suggests that spicy food can curb appetite while also increasing body temperature.
Initial results proved fruitful. The team found that both heat and chilli set off the POMC neurons. In the following 12 hours, scientists noted that the mice ate less food. Moreover, by blocking the TRPV1 receptors, the rodents didn't lose their appetite.
Jo then decided to place the mice in a treadmill where they ran for 40 minutes to recreate a typical session. Their body temperatures rose and remained high for over an hour. As expected, their appetites were visibly lower. Again, by blocking the TRPV1 receptors, the animals were not affected.
Results confirmed that rising body heat lowers appetite.