Mike Geary, the designer and author of the most popular and most down-loaded book of its kind on the Internet, the Truth about Abs, has two main themes in his 120 page program:

Eating the right foods, enjoying them and making sure that it is this that will turn your body into a fat burner, and

Focusing on the exercises that will produce the fastest, most effective, exercises you can engage in!

You have to burn the fat off of your abs in order to start toning them up and the only way that you will accomplish this in a continuing way is to make sure you have the proper nutrition.  That truth about abs can only be done by eating, and enjoying, the food that will do that for you!  There are many foods that will activate your fat burning machine and Mike goes into them in great detail.

Geary says that you will need to change the way you schedule your meals and he does talk about your need to eat less at each meal but eat more meals!