So whatdo you do when you can only keep a hand full of foods and drinks down and your step son is so…

So whatdo you do when you can only keep a hand full of foods and drinks down and your step son is so picky bc you have the last of what he wants he wines for it and throws a fit? Like seriously ive always been "kids come first when it comes to food" but we have a house full of food and a child who only eats very little things bc he refuses to try nee things or to eat the things he used to like that he i guess doesnt like no more. Do i give him the food off of my plate or give him something different and hope he eats it?