I recently scored in the "Excellent" category on our annual health assessment for insurance. My goals for 2014 are losing the fat I've still got, mainly in glute area.
My max weight about 5-6 years ago was 300lbs. I got it as low as 205 this fall, but starting biking to work and doing endurance training (currently up to 30 mile loops) and promptly gained 15 pounds of almost all muscle. I weigh myself every week but I also keep an eye on body fat, overall well-being, et cetera. Weight is only one part of the dynamic!
For those losing weight but looking at long term control, first cut out the low hanging fruit (sweets, junk food, empty calories like soda). Then work on portion control BEFORE totally overhauling a diet (e.g., doing something drastic like Atkins/paleo/etc). That's what really worked for me and after the first year of dramatic weight loss (~60 lbs in one year), I've never weighed more than 230, even when I was a lazy ass.
With my frame size, I will probably stay around 215-220 even in perfect condition. I've got maybe 20lbs left of fat on my frame, but could easily add that back in muscle mass. I'm built like an American football player and doubt I could every healthfully weigh less than 190, unless I had weak, weak muscles.