Fasting dates back to the ancient civilizations of Greece and the Near East. Fasting as part of a religious practice has been used by numerous cultures and religions. Christianity, Judaism, Gnosticism, Islam, Buddhism, Hinduism, South and North American Indian traditions all utilize some form of fasting.
The obesity epidemic continues to progress at an intense rate here in the US as well as other developed countries. And yes, though the food we consume plays a HUGE role, not to be forgotten is the dramatic impact of hormones, in particular thyroid hormone.