Unnourishing is a word that is typically applied to describe food that is not nutritious or healthy. Synonyms for this word are plentiful and can be used to add variety and depth to your vocabulary. Some of the most common synonyms for unnourishing include insipid, tasteless, bland, flavorless, and dull. Other options might include insubstantial, empty, inadequate, unsatisfying, and junky. These words can help you to convey more precise meanings when describing food, and they can also be useful for creating a more nuanced understanding of nutrition and health in general.