There are foods which are nutrient rich and a great addition to our regular diet, there are foods which are nutrient poor and high in calories which we should restrict, and there are plenty that fall somewhere in the middle. 

Here we will focus on what we typically label as 'bad' or 'junk food'.

If we understand a few things it helps us realise they aren't really, really bad, we just need to make informed decisions (you ultimately decide what you eat day to day). 

Our overall diet should be filled with nutritious food, but we don't need to completely eliminate less nutritious products.