I've never had much of a waist, considerably less so now in middle age. This swimsuit is a miracle. The inner lining really does add shape and definition to my waist and is very flattering. You need to tug a bit to put it on, but I'm more than happy to do that! Worth every penny not to look like a beach ball on the beach. If you're in a quandary about size, I'd recommend that you go ever so slightly down a size rather than up. I went for the 14 (which might have been slightly risky in a UK swimsuit) but was perfect.