It is wrong to say that certain articles of food are healthy or unhealthy. Wholesome and unwholesome are the right words. A pig may be healthy or unhealthy while alive; but after he is killed and becomes pork, he can enjoy no health, and suffer no sickness. [Eliza Leslie, "Miss Leslie's Behaviour Book," Philadelphia, 1839]
Healthsome is from 1530s in the sense "bestowing health."
early 15c., sanite, "healthy condition, health," a sense now obsolete, from Old French sanité "health," from Latin sanitatem (nominative sanitas) "health, soundness of body; sanity, soundness of mind; reason; correctness of speech;" from sanus "healthy; sane" (see sane). Meaning "soundness of mind" is attested from c. 1600.