There are actually two kinds of hunger: one is called steady hunger, and the other is called hedonic hunger.

"steady hunger" is very easy to understand, that is, "hunger" in practical sense. When there is nothing in our stomach, it will contract. If we don't eat at this time, it will cause slight dizziness, trembling and blood sugar reduction. And this hunger represents our body's thirst for food and energy. There is another kind of hunger in our bodies, which is called "hedonic hunger". It refers to the "pseudo-hunger" caused by external stimulation and the desire for food when we don't need to eat. This hunger represents the human body's desire for satisfaction and happiness. So, when will this type of hunger appear?

So far, the most common theory is human's preference for food. Now that the living standard of all of us is good, people can enjoy delicious food through various convenient networks, so people's demand for food does not just stop at satisfying food and clothing, and enjoyment has become a more basic driving force. When there are more delicious foods, our brains will look forward to them more. To put it more simply: greedy. The physiological explanation of craving is that the body needs dopamine.

Dopamine is a neurotransmitter, which can affect people's emotions and feelings. The secretion of dopamine is related to eating and sleeping. If the concentration of dopamine in our body is too low, it is likely to cause depression, obesity and fatigue syndrome, and some may even lead to attention deficit and hyperactivity disorder. And if the dopamine concentration increases, it will make people feel happy and happy. At present, most young people will find themselves spontaneously trying to improve dopamine secretion because of long-term lack of sleep, stress and lack of time for exercise, so eating is the most convenient and quick way. ?