Stick with a good diet. Take in less calories than you burn (exercise + BMR) and you will lose weight.
Last June I was 265ish, and WAY beyond unhealthy.
I tracked EVERYTHING I ate for 4 months, dropped caloric intake to 1500-1750 / day, and started running (C25K).
On Jan 1st this year, after eating like crap over the holidays, I weighted 195. I want to weigh between 195-200. I feel good being 'bigger'.
In the time from June to December, my running ability increased from being able to only go 1 city block (1 side!) to running a 10k on Halloween in less than an hour. On Dec 14th, I ran the last race of the year, Jingle Bell 5k in New Baltimore, in 26:30.
Now I'm training for a triatlon in June, and one or two half-marathons this year.
It was HARD to stop losing weight at first, but now I seem to have stabilized, and am holding steady.
In addition to running, I started doing some body weight exercises (pull ups and push ups) to keep muscle mass.
I could only do 1 pull up, and 8 push ups when I started, but now can do 5 pull ups, and 5 sets of 25-35 push ups.
I feel so much better now, and eating right is about 99% of it. I eat greek yogurt and kashi go-lean for breakfast (1cup ea), a banana about 2 hours later, an apple and a hand full of almonds at 10-10:30, lunch (750-1000 calories) at noon, a cereal bar (special k 90 calorie) at about 3, and dinner at 6 (500-750 calories). Some nights, if I am craving something sweet (terrible ice cream tooth) I'll have a skinny cow bar / sandwich (140 calories).