Here is an article that explains food cravings. It helps to understand why we have a need for certain foods and what is lacking in our body for this to happen.
Another great article from the Collective Evolution about Food Cravings. These cravings are detrimental to any diet but indicative of a deficiency in your body. They are the result of an imbalance in your gut bacteria and need to be tested and cured. So, if you have this condition, it is best to have it checked out.