Pasta Portion Size

This is a random fun fact from Dr. Oz. He was trying to bust diet myths and one of the myths was that pasta makes you fat. Actually it turns out the obscene amounts of pasta that we eat as well as what we put on top of it is the real problem. He said that the proper portion size is if you make the a-ok sign and put dried pasta through that. Maybe he makes the a ok sign different than me; but that's a lot of pasta when really I thought it would be about the size of a rivet nut. Do you tuck your finger under when you make this sign?