Is what I have eaten today healthy?

Yes! if the spaghetti, toast, and sandwiches you are eating are all whole wheat! Especially since you are a 17 year old boy, and you are doing 2 hours of kickboxing! But please eat more fruits and vegetables I see 2 servings of lettuce, and oven cooked potatoes, but you need 6-10 fruits and vegetables a day! And on your potatoes don't peel the skin that is where all the minerals are:)