Advice on weight, fitness, exercise and diet.?

Okay, I'm 16 5f 9 (i think), male and 159 pound (72.5 kg). I don't want to lose a load of weight, just tone up and lose a bit of a belly. In august I lost 10 kg from running every morning. Weather is too bad at the moment so I am doing kickboxing. Haven't noticed much change in weight though. I think my diet is healthy as I did nothing for a month and I didn't gain or lose a pound. Any advice on what to do? There is a three mile jog I could do in my spare time, weather permitting. Please, I need advice...