With young adults and adolescents making up the majority of social media users, exposure to this type of content can lead to developing unhealthy behavior. History
In a 1997 article in the magazine Yoga Journal, the American physician Steven Bratman coined the term "orthorexia nervosa" from the Greek ορθο- (ortho, "right" or "correct"), and όρεξις (orexis, "appetite"), literally meaning correct appetite, but in practice meaning correct diet. The term is modeled on anorexia, literally meaning "without appetite", as used in the definition of the condition anorexia nervosa. (In both terms, "nervosa" indicates an unhealthy psychological state.) Bratman described orthorexia as an unhealthy fixation with what the individual considers to be healthy eating. Beliefs about what constitutes healthy eating commonly originate in one or another dietary theory such as raw foods veganism or macrobiotics, but are then taken to extremes, leading to disordered eating patterns and psychological and/or physical impairment. Bratman based this proposed condition on his personal experiences in the 1970s, as well as behaviors he observed among his patients in the 1990s.
Institute of Technology, a university in Bangalore, India
Providence Elementary School, an elementary school in Chesterfield County, Virginia

Computing
Pro Evolution Soccer, a multi-platform video game series developed by Konami
Packetized elementary stream, part of the MPEG communication protocol
Peripheral Event System, an implementation of autonomous peripheral operations in microcontrollers
PSTN Emulation System for IP Multimedia Subsystem (IMS)

Organizations
Postal Express Service, United States military mail during World War I
Power Engineering Society, now the Power & Energy Society of the Institute of Electrical and Electronics Engineers
Premier Election Solutions, formerly Diebold Election Systems
Party of European Socialists, a centre-left pan-European political party
Social Encounter Party, a Mexican former political party
Solidarity Encounter Party, a Mexican former political party

Science
Pallasite Eagle Station, a pallasite meteorite grouplet
Photoemission spectroscopy, a measurement of a substances binding energy using the photoelectric effect
Poly(ethylene succinate), a type of polyester
Polyester, an artificially produced organic chemical that is spun and woven to make fabric
Polyethersulfone, a thermoplastic polymer
Potential energy surface, in physics and chemistry
Programmed electrical stimulation, a type of electrophysiologic study
Pseudoexfoliation syndrome, an eye problem

Other
PES (director) (born 1973), film director and animator born Adam Pesapane
Passenger Environment Survey, quality-control system for transit systems
Payment for ecosystem services, incentives offered to farmers or landowners
Pensarn railway station, Gwynedd, Wales, by National Rail station code
Price elasticity of supply, a measure used in economics
PULHHEEMS, a system of grading physical and mental fitness used by Britains armed forces

See also
Pez (disambiguation)