I'm not sure how thin you have to be to be considered a thin cyster, but I am just under 5'7" and 134 lbs which certainly isn't overweight. I have skinny arms and legs and I like my butt too. However my waist and gut are HUGE. The rest of me being thin only emphasizes this. The doctor says it is my PCOS and insulin resistance but it won't go away. I have lost a lot of weight (20 lbs) since going on Metformin but my waist stays the same. I run and try to eat healthy and high protein. The skinnier I get the worse it looks. Does anyone else have this problem?