Does eating sweet foods affect the taste of eating less sweet foods after that?

Yes. A normally pleasant sour or bitter food can taste unpleasantly sour or bitter if taken after a mouthful of very sweet food. For example, an Apple might taste sour if bitten into after one eats a piece of very sweet candy.

The practice of "cleansing the palate" developed for this reason. Sometimes a small dish of tangy sherbet is served between the courses of a large meal, or a starchy cracker is eaten between sips of different wines.