I've let myself go in the last several years more than I should have, especially with as fit as I actually was in my competitive fighting days, but I've been gradually getting back a bit in the last several months since everything has kind of died down for me a bit.
I've found a lot of success (losing 50+ lbs) in the last six months or so just by general portion control, carb cycling, regular bodybuilding-style workouts, and HIIT (High Intensity Interval Training).
I'd definitely recommend the carb cycling eating program and HIIT, especially if you can't do long forms of cardio. HIIT is essentially short bursts of intense cardio followed by short periods of rest. Essentially, it's like doing a set amount of wind-sprints followed by timed rests. So something like 5 100 yard sprints with 1 minute of rest in between. You can even do it on stationary bikes with resistance, which is what I do.
It's pretty rough starting off, but it's empirically proven to be one of the best workouts to jump-start and increase the metabolism for days.