Here's my bit of advice: chew all of your food until it is paste-like in your mouth. It takes you longer to eat, but you end up eating so slow that you fill up faster then you think you will. That, and it's a sort of "pre-digestion" that your stomach will love you for.
It's great that you're trying, but remember, if you don't get it off now, it'll be 10x more difficult every decade.