Your question is really good and complex.

Current research on animals shows that the vast majority of animals eat between sunrise in the morning and sunset in the evening. I think this was also the case for humans in the early days, because the food in the body is exhausted in the morning. , because we have to rest at night and cannot forage as we like during the day, so this must be the physiological and environmental factors of eating two meals in the morning and evening.

To eat on time, you must first have an adequate source of food. Without a stable source, it is impossible to eat on time. From this point of view, the formation of three meals should have been formed after primitive agriculture, which ensured the stability of food sources. Even with the primitive breeding industry, the supply of food has become more abundant.

With primitive agriculture and animal husbandry, people got rid of the situation of foraging in the wild, which ensured adequate sources of food. The handicraft industry also generated due to the needs of production and life, played an important role in Agriculture and animal husbandry have played a promoting role. The division of labor in the industry has gradually changed people's social division of labor. Different people are engaged in different industries. Eating at any time will inevitably affect work efficiency, and heavy labor must supplement the necessary energy. To maintain physical strength, a three-meal system was gradually formed. Eating in the morning was to prepare for work in the morning, replenishing physical strength at noon so that one could continue working in the afternoon, and eating in the evening to get through the long dark night. In other words, the three-meal system was formed naturally, and its formation must be related to the social production and life at that time. As for whether we are used to three meals or not, I think it is secondary. There is no big discomfort between eating two meals and three meals in a short period of time.

As for the issue of physiological adaptation, what I want to say is that it is not a short-term matter. It may be decades or hundreds of years. In short, once you adapt to the environment, you will naturally exist in this environment. , those who are not suitable will be naturally eliminated.

In other words, sufficient physical goods, social development at that time, and the emergence of various occupations gave rise to the three-meal system.

As for snacking! ! From my point of view, it is an ancient habit left by primitive people, and they eat whenever they have nothing to do. Haha, just kidding, it makes sense not to allow snacks.

1 It affects the normal physiological functions of the stomach and causes the stomach to wriggle constantly. Not getting necessary rest.

2. Snacks are generally different from staple foods. Most of them are high-calorie foods, which can easily cause social problems such as obesity. In addition, their packaging is also thrown away, affecting public health. Naturally, it arouses disgust and opposition

3. The consumption of snacks may be greater than your consumption of staple food. Naturally, it will be opposed by your parents, which increases the financial burden.

4 Unlike after eating staple food, you rarely brush your teeth after eating snacks, which can easily cause dental diseases!

I don’t know if you are satisfied or not! Haha, I understand it all, and I don’t know if it is correct!