Will i lose wieght doing kickboxing?

i am 5'8 154 pounds but i appear a little bit bigger then i actually am (i look about 170+ because i train my upper body alot and i just recently starting to try an pack on muscle on my legs...i have chicken legs :( lol ) i want to start thia kickboxing soon and the only thing i'm afraid is that i will lose wieght and i work so hard to have the wieght and body i have now i don't wanna lose it any ideas or ways to maintain wieght while doing kickboxing?