Balance and moderation. It is unsustainable to omit any and all "bad foods." If you aren't sure if a food is healthy or not, ask yourself where the ingredients come from, i.e. plucked from nature (fruits, vegetables, meats, eggs) first.
You should strive to eat more foods that provide you with nutrients such as those just mentioned, and limit products that are processed. Follow an 80/20 rule, eat 80% healthy real foods and 20% other. This can be done daily or weekly!