I've lost all my weight back off also. Been 6'2 180lb all my life, then when I started on medications I blew up to 300+lb also, (about 2 years back) now I've taken it off, and only eating only pure foods, and I'm down to 180 again, took several years, but I'm back down. I need to maybe go 10 lbs further because of muscle atropy, when I was at my prime, I was 190-210lbs, solid muscle. Those days are long behind me. I also try and use food, instead of medicine for my troubles, and put good things in my body to counter anything bad, like the smoking.
Body gets assaulted by everything from pathogens, toxins, heavy metals, ect. It needs the proper fuel, not garbage to rebuild and repair itself. It's just that simple. You either change, or you die, unfortunately. That's the alternative, and it's very much the reality of things. Your body can only take so much abuse,
It's got to have the exact biochemicals it needs, or a cellular decay occurs
Many cells lose their ability to function, or they begin to function abnormally. As aging continues, waste products build up in tissue. aka DNA damage, or parts gone missing...
our bodies, are much like replicating isolated cannabis genes... When you've got instructions for very isolate tissues, and you lose the instructions, or write a new set of instructions, it becomes pathological. When your young and strong, your got much better "memory" built into your cells, but toxins, and inactivity greatly reduce this capacity. Bad nutrition is further assault...