One principle that I try to keep in mind when seeking mental input, whether it be reading an article/book, watching a video, or going somewhere: am I seeking emotional or intellectual stimulation?
Just as a diet of mostly sugar is unhealthy for the body, a constant diet of mental "junk food" is bad for the mind. Junk food is not a problem, as long as it is eaten in moderation.
If someone has unhealthy eating habits, they must first recognize it and then monitor what they eat. If you (As I did in the past) realize that your mental diet of input is mostly junk food that doesn't appeal to the intellect, recognize that you should change something and then monitor everything that goes into your mind. Do you really want to listen to that pop music station? Maybe instead you could listen to the news, or a download a lecture onto your phone, or maybe try to learn Spanish in your car...?
Like eating vegetables, adjusting what you mentally "eat" can be challenging at first, but over time you will prefer it over junk food.