I lost 80 lb. in less than a year. 7 years ago (260-180) and I did it by cutting my calorie intake, drinking a lot of water, running/cardio for 25 minutes a day 3 or 4 times a week, and lifting weights 3 or 4 times a week. I didn't eat anything past 8:00 at night, and did my cardio a few hours before I went to bed. My metabolism stayed high while I slept, burning more calories.
I did not change my diet as far as what type of food I ate, I just changed the amount.
Instead of a quarter pounder, 6 piece Mcnugget, Large fry, Large Coke.
I would eat a quarter pounder, med fry, med coke.
The hardest part is starting, for a long time I made little progress and had little results. After about 6 weeks the pounds starting coming off, my energy level picked up and it was great waking up everyday and hopping on the scale.
As far as cardiac health though.... it would probably be a good idea to lay off the high fat, artery clogging Mickey D's.