Started with a "Biggest Loser" style contest at the place I worked at a few years ago... had already dropped 20 pounds before the contest started, lost another 20 in the two months of the contest and was 3rd place "loser"... the only one who kept that weight off and lost more after. Lost most of it with a lot of cardio, weight lifting, and low carb/low fat/high protein diet.
Fast forward to April, 2018 - spent 1.5 years with a guy who had me drinking 1-2 bottles of rum every week... eating relatively unhealthy, not working out, etc., and gained another 20 pounds on top of what I had already gained after the shoulder surgery in 2014 and broken wrist in 2015. I quit drinking, we broke up two weeks later, and I am back on track to where i need to be. Shoulder still gives me occasional issues four years later but I know my limitations and I push them often.