Eating

I have a 1 year old and some days he will eat a lot but other days like today he barely wants to eat anything and no matter how much I try to get him to take more bites he won’t or it will take FOREVER for him to take one bite. Or he’ll throw all the food on the floor. Should I be worried? It’s such a little amount of food that he eats that I’m worried he isn’t getting what he needs but it’s a struggle to get him to eat anymore. Advice? I’m a first time mom..