I don`t believe we are their food. We just get in the way of their food and, as a result, may accidentaly get bitten. I haven`t heard of a shark "feeding" on a person...you usually just hear about a shark "bite". So I guess once they realize they made a mistake and took a bite out of the wrong thing...they don`t come back for more. I`ve heard that you`re more likely to get struck by lightning than get bitten by a shark.