toddler doesnt eat

my 2.5 year old (3 in July) eats like a bird. we always have offered a wide variety of foods, but he hasnt been touching it. we give juice (watered down) through out the day and milk at night. mornings he seems the hungriest, usually eats a waffle and has milk. other than that, he will only eat like once more in the day.

he was not underweight at his last appointment. if he goes all day without eating, we will offer noodles and he usually has no problem downing them. what can i do to get more nutrients in him??