Nutrition is just as important before you get pregnant as it is during pregnancy. So start now by replacing soft drinks with water. There is no nutrition in soda to help your body get ready for the stresses of growing a baby. Water helps clear the body of toxins to make sure you are in top shape before you conceive.
Try to eat foods that are high in fiber right before eating full meals because they will help you to eat much less than you would have otherwise. A good example of that is eating an apple before each meal, since apples are very high in fiber.
Increase the amount of fruits you're eating by making a breakfast smoothie. Throw some low fat yogurt, fresh frozen fruit of your choosing, a banana and some milk into the blender. Blend until smooth and enjoy! You can hide all kids of healthy ingredients in a smoothie that you won't be able to taste at all.