Source : Webster's Revised Unabridged Dictionary (1913)

Nutritious \Nu*tri"tious\, a. [L. nutricius, nutritius, from
   nutrix, -icis, a nurse, nutrire to nourish. See {Nurse},
   {Nourish}.]
   Nourishing; promoting growth, or preventing decay; alimental.
   -- {Nu*tri"tious*ly}, adv. -- {Nu*tri"tious*ness}, n.

Source : WordNet®

nutritiousness
     n : the quality of being nourishing and promoting healthy growth
         [syn: {nutritiveness}]