What causes aa man to crave lots of green olives 30_40 at a time?

Anemia: Iron deficiency anemia is a well known cause of unusual cravings. Although, eating olives is not that unusual, but if it is a new craving for you or definitely something unusual in your opinion, it may be worthwhile checking for. If it is not that, then I am not sure. People's tastes and cravings change over time. I used to hate olives myself, but i eat them almost daily now.

Nucleus Accumbans: Olives are high in calories, but have the healthy type of fatty acids. Compulsive, uncontrollable consumption may  be indicate abuse/dependence which is modulated by a Dopamine surge in the reward center of the brain. Otherwise, they are delicious, .