What should I do if my trousers are fat?
Remove the belt, remove the pleats on the trousers, sew them to the size suitable for your waist, and then remove the belt (the same color as the surface) and connect it to the surface to the appropriate length. Just find a piece of cloth with similar color to fill the position inside the belt, because it is invisible, and then sew the belt on the pants.
Waist refers to the upper part of trousers where the belt is tied.