1. Quite a few people have thin genes. No matter how much they eat, they will never get fat.

As the saying goes, no matter how much a person eats, he is always in a bad mood, which will affect the absorption efficiency.

3. the spleen and stomach are not good. This kind of person usually has a big stomach fire, but it is not well absorbed, but it is not stunted.

It may be caused by some diseases, and there are many specific statements. If you are worried, you should go to the hospital for examination.

I hope I can help you. In fact, being thin is not easy to get many diseases.