I have the same problem and I also eat healthy, so I guess I'm gonna try to do sit ups and crunches hopefully that works
Try weigh cruches,weigh hangin knee rasies,russian twist do trisets back to back,aim for 4 sets of 12 reps each . Good luck
Cardio is the best fat burner. But if your also looking to tone up throw in some HIIT (High Intensity Interval Training) exercises. These exercises force you to work hard in short intense spurts with little recovery time in between. The result is greater after burn (the amount of calories you burn after your workout is over).
HIIT exercises give you the mix of cardio and strength training in one workout.
Also focus on exercises that hit your entire core (abs, hips, obliques, lower back, and butt). If any of these areas is weak it will make you stomach look bigger than it actually is.
I built my HIIT exercise (Core Blast, Sexy Booty) from workouts I found here and at ab-workouts-guide.com Its aimed at hitting the areas listed above. If you like it checkout Core Abs & Stretches, Cardio Fight Club HIIT, P90x: Ab Ripper X, or Core & Glute Kicks they're fun and challenging.
Good luck and God Bless!