Different cultures. Since the Renaissance, Europe and America have been pursuing individual freedom and liberation. A large number of literary sculptures and paintings have nude images, and athletes in ancient Olympic Games were naked. As soon as they take off their clothes, they will naturally advocate bodybuilding.

-Different nutrition. Children in Europe and the United States have good nutrition since childhood, and it is normal to be big, just as the post-90 s and post-00 s are generally taller than the post-70 s and post-80 s;

-Pursuing sports. In Europe and America, it is equally important for students to go to the gym and the library. Few students don't have a fitness card.

-different living habits. It is normal for men in European and American countries to go out shirtless as long as they don't go to church, office and other serious occasions or formal shopping malls, and they will not be regarded as uncivilized behavior like China. Men need to be muscular if they want to go shirtless, otherwise they will be embarrassed.