Getting a job where I sat in a patrol vehicle driving in circles all day, coming home tired and not exercising; all the while eating like I still worked at a lumber mill.
I dropped some of that weight, but then was diagnosed with type 2 diabetes and went on insulin... when I was at a high enough insulin level I ballooned up and gained 65 pounds in less than six months.
I was able to cut my insulin down by exercising and taking a supplemental oral medication. I have lost 60 pounds in three years and kept it off for the most part give or take 10 pounds either way.