Orthorexia is an eating disorder first identified in 1997 that describes a pathological obsession with healthy eating, to the point where it disrupts a person’s daily life and damages their health.
According to Yahoo! News:
Orthorexia is a recently identified problem which Dr Steven Bratman was the first to describe in 1997. The term comes from the Greek “orthos” meaning right or correct, and “orexis” which means appetite.2 This eating disorder is characterised by a pathological obsession with eating healthily and ends up with numerous food restrictions. Orthorexics will often exclude any food from their diet which contains pesticides, herbicides or other chemical products from their diet.
Special thanks to Jeannie Moulton for the tip! You can read more about orthorexia here.