Yes, but you have to wear them at least every night for a year to see any significant change.
I recommend eating less

Plus having a smaller waist is preferable to having a bigger waist as a woman....but for a man I don't think it makes a difference. So long as you have a defined stomach, I personally don't think waist size matters much. As a girl, I don't like men with super tiny waists, I think thicker ones look more impressive/stronger.