What do you do if/when your baby throws food on the floor?

I know it is a developmental stage but this is getting crazy. LO throws almost 70% of food on the ground as he seems to be very amazed by how the food drops to the ground. The thing is he is actually still hungry because when I finally pull out a jar and start feeding him, he'd eat the whole jar!

Our pediatrician and nutritionist both says ignore him and do not show any response to this behavior because he's just seeking attention and he thinks its funny because it causes a chain effect (But I really think he's more obsessed with seeing the food falling onto the ground). Our ex-nanny say I need to slap his hands lightly and firmly say no because he needs to learn to not do that.

What would / do you do? Did you succeed in correcting the behavior?

And what I want to know is, does this eventually stop??