These definitely slim and even lifted my butt instead of squishing it flat, but they do not stay up. Maybe my expectations are too high, but every time I sat down the back would get pulled down (I'm only 5'2" so its not that I'm taller than average). Then I had the dreaded and unfortunate back boob between my shaper and my bra. To get them pulled back up I had to go to the bathroom and contort myself to restore the shaper to its original position. These would probably be fine with tight pants and a bigger shirt, but not if you're wearing any fitted top.