I've noticed with passing interest the phenomenon among my fellow evangelicals of adopting fad diets that market themselves as somehow being "biblical." Certain authors (not to mention "Christian" chiropractors and dieticians) have made a mint putting Christians back under the Old Covenant law.
The unexamined assumption here, almost universally believed, is that God gave Israel the dietary laws primarily for health reasons. But such a view of the law is not sustainable by the text. As if God somehow wanted to take away these health blessings from the church when He pronounced all foods clean again in Acts 10:15.
Nonetheless, such diets have found a fertile market among food-phobic evangelicals. In a fascinating ongoing series, Doug Wilson looks at how we got that way and why it's wrong. Start at the bottom and read up.