Sweating when eating can occur for several reasons. The most common cause is eating hot or spicy foods, which contain chemicals like capsaicin that trigger the body's heat sensors and cooling response, including sweating. This is a natural way the body tries to cool down when it thinks it's overheated. Additionally, very hot foods in temperature or acidic ingredients like vinegar can also induce sweating. Another cause is a medical condition called gustatory hyperhidrosis or Frey's syndrome, where nerve damage around the salivary glands causes sweating on the face while eating, even with non-spicy foods. This nerve miscommunication leads to sweating instead of or in addition to salivation. Other underlying conditions affecting nerve function, such as diabetes or Parkinson's disease, can also cause sweating during meals. Certain foods like very high-sugar meals can cause insulin spikes followed by reactive hypoglycemia, which may also trigger sweating. Finally, eating large amounts of protein can generate metabolic heat during digestion, causing some people to sweat as the body expends energy breaking down food. In sum, sweating while eating is most commonly due to spicy or hot foods, but it can also be a symptom of nerve damage or other health conditions affecting the body's control of sweating.
