Sweating profusely while eating... How does diet affect body temperature?

Zhang Yu

Why do we often sweat profusely when eating, but feel warm immediately after eating something when it's cold? Have you ever wondered why? How does food affect body temperature?

Hello everyone, I am Dr. Zhang Yu. Body temperature is one of the four major vital signs of the human body and plays a very important role in our life activities. Will body temperature change? What factors will affect it?

Maintaining a stable body temperature is a prerequisite for humans to spread all over the world. However, even so, our body temperature will fluctuate at different times of the day. Generally speaking, body temperature is affected by physiological state, ambient temperature, warmth, exercise and other factors. In addition, diet can also affect body temperature. But how does it happen? As I just said, eating does increase body temperature. This phenomenon occurs to everyone. It also has a professional term called food thermal effect - the phenomenon of increased energy consumption caused by eating.

So how does the thermal effect of food come about? It turns out that when we eat, the movement of the digestive system, the secretion of digestive enzymes and the absorption of nutrients all require heat. When the sugars, fats and proteins in food are oxidatively decomposed, they will also increase our basal metabolic rate and stimulate the body to release additional heat, which is dissipated in the form of increased body temperature and sweat volatilization, so as to maintain our body temperature relatively constant. It can be simply understood that the engine will also generate heat when working, and it needs water tanks and other devices to release heat. So what factors affect the process of food affecting body temperature? Studies have found that the increase in body temperature will occur shortly after eating, and this will be more obvious in the cold winter. The body temperature will reach its peak two hours after the meal, and it will slowly return to normal after 2 to 3 hours. Different foods produce different food thermal effects. Generally speaking, the thermal effect of protein is higher under the same weight, which can reach 30% of the basal metabolic rate, while carbohydrates and fats can only reach 4 to 5%. According to the eating habits of Chinese residents, it generally accounts for about 10% of the total calories. The speed of eating also affects the thermal effect. Generally speaking, the faster you eat, the more energy you consume. In addition, the temperature of the food itself also has an impact, because the temperature of the food will be transmitted to our digestive system, which is why the hotter the food, the easier it is for us to sweat.

According to this theory, if we strictly control our diet, can we lose weight by eating more hot food? This is theoretically feasible, but it is not feasible in reality and is harmful to health. On the one hand, too hot food is not good for health, and on the other hand, long-term control of calorie intake at each meal to ensure that it is below the basic metabolic range can easily lead to protein energy malnutrition, so I advise you to give up this idea.

So what is the right temperature for food? Neither too high nor too low is good, and both may harm our delicate digestive tract. For example, many people like to eat hot food, which will burn our esophagus and gastric mucosa. Usually, the tolerance temperature of the oral cavity is only 65 degrees Celsius, while the esophagus and gastric mucosa are only 45-50 degrees. Once the mucosal cells are burned and necrotic, repeated repair will cause squamous epithelialization, which will increase the risk of cancer over time. So in the future, when we entertain guests, no matter how enthusiastic we are, we should not say "eat it while it's hot, it will be cold in a while". This sentence is actually wrong. So is there no problem with cold food? Of course not. Too cold food still has an effect on the movement of the stomach. The way our body digests food is to bring the food to our core temperature first. For example, it only takes 15 minutes for us to digest and absorb hot soup, while cold food, especially ice cream, takes 30 minutes to two hours to digest. So it is recommended that you should not drink too cold drinks when eating. Now you understand.

When eating, your body temperature rises and you sweat, which is a normal physiological phenomenon. More importantly, don't eat too hot or too cold food, and don't eat too fast, as these are not good for your health.

This article is a work supported by Science Popularization China Starry Sky Project

Author: Zhang Yu

Review: Tao Ning

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.