Eat a lot but be thin. What is the reason?

Everyone's physique is different. There are indeed some people who are not fat, and these people are mainly children, and there are fewer adults.

The reason why adults don't get fat is that they eat a lot, but their metabolism is particularly good, and her food will be consumed quickly. It is normal for children to eat dry food without getting fat. If a child suddenly begins to gain weight one day, it means that his height has stopped growing.

Children need a lot of nutrition when they grow up, so they will eat a lot. The metabolism and exercise of organs are very large, and they all need energy. ?