[Mithadan]

I was thinking more in terms of why, in terms of the mythos, Hobbits might be longer lived than average humans. I do not disagree with any of the "clean living" comments above, other than to note that the Hobbits lived in a primarily agrarian culture which sometimes is less conducive to longevity.

The Dunedain were longer lived in part as a reward for their loyalty and service during the First Age. Could there have been some merit inherent in the Hobbits that justified their longer lives? Or perhaps their role in events could have somehow been foreseen, or even planned by Eru? There is, to my knowledge, no direct textual evidence of this, so I am speculating.

Letters provides some very slight insight. Hobbits are described as a branch of the human race that had gone entirely unnoticed by the "great" until the Third Age. Letter no. 131. So it could not be said that they were involved in any of the great events of the First Age (a certain RPG to the contrary). However, Bilbo is later described as having been "selected by the authority and Gandalf" (because he was abnormal) and they were "ordained individuals inspired and guided by an Emissary." Letter no. 281.