No, it just means you're buring more than you eat, ergo you're buring calories already stored in your body. (fat and suger!) It's a good thing to have happen, just be sure you're burning less than 2000 extra calories a day... you don't want to get dizzy while driving or something!
"I'm through accepting limits cause someone says they're so, Some things I cannot change, But till I try, I'll never know!" - DEFYING GRAVITY