Help! My nephew is such a picky eater. :( How can I make sure he gets all the nutrients he needs when he only wants to eat Jollibee!

I feel you. Kids these days are really picky eaters especially when they already have been introduced to the commercially available food restaurants and fast foods. I suggest to extend your patience and be creative in showing different options of food when feeding him. There are a lot of creative bentos made by parents nowadays which you can get ideas from. Sharing you links to some of them: http://www.hongkiat.com/blog/creative-and-interesting-bento-boxes/ http://greatist.com/health/healthy-bento-box-ideas

If he's a really picky eater, I would start by mimicking the menu of Jolibee but make sure that it is homemade. It wouldn't be the healthiest but at least you'd know what's in it and it'll be a good transition for him to other dishes.