Can you boost metabolism?

[Solon]

I'm participating in a research study where yesterday they calculated the amount of calories my body burns at rest by having me breathe into a little helmet-tent, and then measuring the amount of carbon dioxide.

According to the research nurse, someone of my height and weight should require about 1750 calories a day just to keep the vital organs going. My test results, though, indicate that I only burn about 1430 calories a day resting. (And, I'm not in starvation mode. I don't eat a lot, but I eat fine.)

In a way, I'm a marvel of evolution, since my body is geared to get by on fewer calories. On the other hand, I'd rather burn a few more so I can lose 5 or have a little ice cream. Can you boost metabolism naturally (no caffeine or energy supplements)? Fartlek training maybe?