Unfortunately, such a diet does not provide what the body needs to function properly. A number of years ago, I was working full-time, going to Bible School nights full-time, and living alone. For a couple of months, I lived on frozen dinners and cereal. One morning, I dragged myself out of bed, wondering why I felt so tired. My body didn't have the fuel to keep up with my schedule. A change of diet alleviated the fatigue and generally yucky feeling.
As readers and writers, do we exist on literary junk food? Our reading habits will not only affect us as writers, but also as people. Content which mocks and undermines decency and our relationship with the Lord may temporarily satisfy fleshly desires, but it will ultimately harm us and affect our quality of life. The Word of God keeps us on track and focused on His precepts. It may cause us to squirm at times and isn't always candy sweet, but is necessary to a healthy inner life.
There's a saying, "You are what you eat." My saying: "You are what you read."