I most certainly do not spend my days fantasizing about food, though naturally i will occasionally think about it as yes, humans do enjoy food and it's pretty normal and healthy to miss it after many days without.
From what I took from the report obsessing could possibly be with items besides food. One could start hording just about anything. It struck a cord since my longest fast (six years ago) I was hording all sorts of items like bath products, clothes and distilled water. My habits only changed months after the fast was completed. And I was not a beginner six years ago.