Serve fortified bread so your kids will be getting iron, vitamins, magnesium, and zinc as well as fiber. Check the label -- whole-wheat flour should be listed as the first ingredient. One way to get kids to branch out from white is to serve whole-wheat bread toasted and topped with melted cheese.
Next-best choice: Brown rice, which has more than three times the fiber of white and twice as much vitamin B6. Instant is fine. You lose a small amount of fiber, but it's still healthier than white rice.
Picky-eater idea: Use cookie cutters to make finger sandwiches in fun shapes. Your toddler will be so excited to eat a giraffe PB&J, she may not notice that the bread is a darker color.