People are used to not eating, what are the consequences?

There is a saying that "people will starve to death if they don't eat for seven days", which may not be so serious, but it is also worth referring to. When you say "people are used to not eating", do you mean not eating anything, or not eating on time, or eating very little at every meal? People need to consume nutrients every day to gain physical strength, and many nutrients must be obtained through various foods. Now that people's living conditions have improved, they can get nutrition from fruits, snacks or nutriments, but sometimes it is too simple, which may lead to malnutrition and cause some symptoms, such as beriberi, oral ulcer, dermatosis and systemic diseases. And sometimes it's not just thin.