I do a lot of strength training, which means I have a super high metabolism now. But I also do something else to keep it from slowing down... I eat every couple of hours.
I bring this up because when I worked out today, somebody asked me how I keep my weight off. He went on to say how he doesn't know why he's not losing weight. He eats breakfast and doesn't eat another thing for like another 7-8 hours, when he has a big meal at dinner time. A few problems with this scenario: first, don't eat a big, heavy meal all at once. Second, don't wait so long to eat.
I try not to let myself wait longer than like 2-3 hours before I snack on almonds or fruit. It keeps my appetite in check. It works because I never get hungry this way.
I used to wait long periods of time to eat, but this was when I was obese. Aside from eating the wrong foods, I would sometimes wait until dinner time to eat a big meal. This is a lot to put your body through. In my opinion, you'll have less energy and you'll end up overeating.
If you do eat every couple hours, remember to eat nutritious foods. There's no point to eat frequently if you're going to end up eating candy bars or potato chips!