I started at 451. I was 409 before surgery an am now 397 2 weeks post op. i started to really feel better after 30 pounds down. At over 500, I think the sleeve will change your life even if you only lose 200 pounds. BUT, they say the average amount of weight lost in the first 18 months is 60% of the weight you need to lose. At about my height, for you that would be 220 lbs. Only about 60% of people reach their goal weight but even if you get below 300 you will feel AMAZING! PS: we always get discouraged when we jave so much to lose and we lose a bunch and still have so much to lose, I have so been there, but celebrate every pound that comes off instead and follow the plan and don't think about what still has to come off. It is a new way pf thinking my counselor is trying to help me adopt. Good luck!!! I wish you many pounds lost!