In a study published in the journal Emotion, researchers primed participants to experience either love, jealousy, or a neutral feeling. The subjects then sampled both bittersweet and sweet-and-sour candies and ranked them on taste. Those primed with love reported all of the treats as sweeter than individuals in the jealous and neutral categories.
For the second part of the study, a different group of volunteers was primed and asked to analyze the flavor profile of plain distilled water (they were told it was a new beverage product). Despite the water being unflavored, the lovebirds again claimed the drink was sweeter.