50 synonyms for unhealthy such as ghoulish, baleful, ailing, abnormal, and depraved. Unhealthy is an adjective, and its antonyms are healthy and fit.
Baleful, damaging, dangerous, deleterious, destructive, detrimental, harmful, injurious, insalubrious, malign, noxious, perilous, poisonous, risky, and ruinous.
Ailing, debilitated, delicate, feeble, frail, ill, ill-looking, in poor condition/shape, in poor health, indisposed, infirm, out of condition/shape, peaky, poorly, run down, sick, sickly, unfit, unsound, unwell, valetudinarian, washed out, and weak.
Abnormal, depraved, ghoulish, macabre, morbid, sick, twisted, undesirable, unnatural, unwholesome, and warped.