Craving earth: understanding pica : the urge to eat clay, starch, ice, and chalk

This study provides a portrait of pica, or non-food cravings, from earliest times to current times.

It explains how humans have eaten earth, on purpose, for more than 2,300 years and that people also crave starch, ice, chalk, and other unorthodox items of food.

It details how some individuals even claim they are addicted and 'go crazy' without these items, and asks 'why?' The book draws upon extensive historical, ethnographic, and biomedical findings and describes the substances most frequently consumed and the many methods (including the Internet) used to obtain them.