Nutrition has a great impact on childhood development. Just like as adults what we eat can affect our ability to perform our tasks at home and at work, a child has the same challenges every day. Exposing your child to a variety of different foods and textures is also really important. So you want them to try all types of things. Of course, you want them to eat vegetables. You want them to eat their fruit. You want them to eat lean cuts of meat like chicken.
You also want them to try new foods. So any time you go out to eat at a restaurant have them try something new too. This will actually develop their palate more and have them be less picky and it will also help you because wherever you go they'll be able to try new things. You should also make sure that your child is getting enough dairy, cheese, yogurt is great also and to limit the amount of sugar they take. Really because if you've ever given a child a lot of sugar you'll see for yourself the effect that it has on them and you might see for yourself that maybe that was a little too much sugar.
So limit the sugar. Everything in moderation. And make sure that your child is gaining weight at the rate that they should be by checking in with your pediatrician and voicing any concerns that you have with them at all times.