Hi, elivette95. You should first focus on the amount of calories you need. Then either cut calories or add calories. Cut calories if you are more than 15 pounds over weight. Add a few calories if you only have about 10 pounds to lose.
Now that you know how many calories to consume each day... divide that number by 5-6 meals. So to keep things easy... let's assume you are to eat 1600 calories per day. Dividie that by 6 and you get 267 calories at each meal.
Each meal should include a lean protein (chicken, tuna, turkey, beans, tofu, tempeh, soy, etc) and a good carb (veggies, fruit, sweet potato, baked potato, Kashi GoLean cereal, etc). Drink a glass of water too.
If you are already showing the top 4 abs... then the trick is most likely going to be in the nutrition and targeting the abs properly. Try doing hanging leg raises, reverse crunches and plank pose.