Which of the following is a characteristic of unsaturated fats?

Unsaturated fats are characterized primarily by their chemical structure, which includes one or more double bonds between carbon atoms. This structure prevents the molecules from packing closely together, resulting in a liquid state at room temperature. These fats are typically found in plant oils, nuts, seeds, and fish, making them an important component of a healthy diet.

The other characteristics listed are not associated with unsaturated fats. For example, saturated fats, which have no double bonds, tend to be solid at room temperature and are commonly found in animal products. The claim that unsaturated fats contain no calories is also misleading, as all fats provide a significant amount of calories, making it crucial to consume them in moderation as part of a balanced diet.