Me and one of my buddies use Arson caffeine based fat burners after a long lay off and they work a treat to lose the pounds that have been put on.
I wouldn't suggest long term use but they do help
get you in shape. I say help because they arent miracle pills they help out alongside a healthy eating program and excercise routine.
Liek the dude above said lay off the beer, that's the best way to lose weight. If you feel like going out for a drink stick to vodka and lemonade or something. Also I find (and my coaches recommend) it is unrealsitic to completley cut out junk food. It's good to be bad sometimes and stops things getting boring so once a week (Saturday night for me) get a pizza or McDonalds in you