I am not too large, but have a little bit of a tummy from having 6 kids.  I wanted to wear this to a wedding under a dress in hopes that my little fat roll would be squeezed in.  It didn't make that much of a difference; maybe no difference when I compared my tummy without the body shaper.  I guess the fat has to go somewhere, so I'm not sure why I expected my stomach to look thin.  The little difference that it did make was displaced by the material of the body shaper.