We can see that there are many such examples. Tian Tian, a famous actor, is a typical example. It is hard for us to imagine that they used to be a big fat man of 200 Jin, but now they are so thin. Tian, in particular, is a typical very thin boy. He can't see any traces of ever being fat. In this case, we can't say that we are born fat, because we can lose weight with hard work the day after tomorrow, and the facts have proved that it is true. I don't know if you know that there is a singer named Gao Yang in a famous vocal program. He is thin, too, but he used to be very, very fat. People who lose weight are potential stocks. Why am I not?
And some people have always been thin, but among these people, only a few people should be born thin. Most people are still thin because they have been strictly controlling their weight. Just like a friend of mine, he looks like a born thin man, and he has been eager to gain weight. As a result, he really grew from a thin man to a fat man, which is endless. Until now, he hasn't lost weight, so people who look thin are not necessarily fat.
So I want to say whether it is born or acquired, as long as you want, you can do it.