Brain candy describes an experience that is enjoyable because it stimulates¹ the mind pleasantly, but doesn't actually make it work, usually in reference to light and fluffy² books, movies, TV shows, and other entertainment.

Brain candy（脑轻松）指让大脑轻松愉快的体验。这种体验能够刺激大脑、让其感到愉悦，同时又不会让大脑处于工作状态，多指轻松简单的书籍、电影、电视节目以及其他的娱乐形式。

For example:

No one ever called Star Trek³ great drama, but it makes pretty good brain candy.

从来没有人说过《星际迷航》是一部伟大的作品，但它作为一部轻松娱乐的片子还是很好的。