Weight-loss foods?

It seems I've started putting on weight, and I need to lose my stomach before I become fat. (With clothes on people still think I'm thin. With clothes off... not so much.) However I put the weight on because I eat when bored. And with like 16 hours a day of doing nothing, I'm bored a lot.
So basically I need some decent low calorie foods that don't taste like crap on their own, but I can eat endless amounts of to keep my metabolism high, and still lose weight.
Any ideas?

2/4: Cheers. 4 in particular: Will cucumbers work rather than celery? Celery is a bit meh, whereas I love cucumber.

3: There is absolutely nowhere around here to run. I love to go running, and used to do it all the time with my friends, but I've moved to an area where it's not that plausible.