I carry most of my body fat in the lower half of my body, but I have a small waist. Because of this, most styles and brands fit differently. I went with a size x-small for the bottom (size 4) and it fit perfectly, although it's like putting pantyhose on getting them on my legs. I do CrossFit and I didn't have to worry about pulling them up or them twisting doing high impact workout.
Sara recommended this style