Not eating for a long time will cause malnutrition.
Malnutrition here means that the nutrient absorption of internal organs is not in place. As we all know, the internal organs of the human body need to absorb nutrients and eliminate toxins at different times every day. But people don't eat when crossing the valley, so the stomach can only rely on absorption, and the previous food residue can increase the nutrition of the human body.
A day or two is ok. Once the time is too long, the intestine can't absorb enough nutrition, so the intestine will absorb the previous waste, which is not good for the body, and if you really don't eat for three or five days, just drink water, it will do great harm to the human body.
After the valley, it is easy to overeat.
In those days when the body only relied on drinking water to maintain physical exertion, people must be hungry at that time. To put it bluntly, their stomachs have been screaming for a long time. So at the bottom of the valley, even if they have the mind to control their appetite, they will still overeat more or less under the drive of physical instinct, which will cause a great burden on their stomachs.
Therefore, people who are weak should not learn from others and eat on time. Even people who need to cross the valley because of their beliefs should pay attention to maintaining their health.