The Collaborative International Dictionary of English v.0.48:

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.
   [1913 Webster]

WordNet (r) 3.0 (2006):

nutritious
    adj 1: of or providing nourishment; "good nourishing stew" [syn:
           alimentary, alimental, nourishing, nutrient,
           nutritious, nutritive]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "nutritious":
   alimental, alimentary, assimilable, balanced, beneficial, cannibal,
   cannibalistic, carnivorous, commensal, dietetic, digestible,
   dining, eating, feeding, flesh-eating, fruitarian, gastronomic,
   gluttonous, good, grain-eating, graminivorous, granivorous,
   grass-eating, healthful, healthy, herbivorous, insect-eating,
   insectivorous, lactovegetarian, life-giving, man-eating,
   meat-eating, mensal, nourishing, nutrient, nutritive, omnivorous,
   omophagous, pantophagous, phytivorous, phytophagous, plant-eating,
   postprandial, prandial, predacious, preprandial, salubrious,
   salutary, vegetable-eating, vegetarian, wholesome