The Collaborative International Dictionary of English v.0.48:

Misdiet \Mis*di"et\, n.
   Improper diet. [Obs.] --Spenser.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Misdiet \Mis*di"et\, v. t.
   To diet improperly.
   [1913 Webster]