She was born thin.

There are only three possibilities to get fat.

1. stuntman

make up

gain weight

But obviously it is impossible to gain weight, so we have to double our body or make up. Considering the cost, mj can turn into an old man and jump in space walk, and Andy Lau, who lost weight successfully, can become so fat. It is entirely possible to make up the heroine as a fat girl, so we put silicone or other substances on her and turn her into a fat girl.