There is no way to build great abs without losing weight. Even trying to work for great abs, you will lose weight not even trying. All I do is do regular ab work outs everyday, and then when I have time I run. You won't know if you have good abs until you lose body fat, then your work will start to show. I play soccer so I do a lot of running and so my abs are strong and my body fat % is low even when I don't really diet the way I should be. Good luck, abs and run.
P.S. I am only 15 so I might be wrong with my advice.