When you wear the wrong size clothes you put more kilos on.
If it is bigger or smaller you are creating a visual illusion.
If you wear smaller clothes the viewer thinks you have some extra kilos because your clothes don’t fit you. If your clothes are bigger you create the illusion of being bigger of what you actually are.
Annalynne Mccord wears a belt that creates the visual illusion of a lady with extra kilos. (Of course we know she is in a very good shape but this is an example of how clothes can work against you)
The right size of your clothes creates a total impact in your image. Smaller and bigger clothes give the impression that you are actually bigger than your real size.
Lea Michelle was also seen out and about with clothes that make her look bigger.
Choosing the wrong size can bring a lot of problems. One example is Abbey Crouch who spent the whole event worrying about showing more than normal with her low-cut dress.