However, recently, some scientists have been growing more vocal about dietary recommendation that have less to do with personal health, and more to do with the planet's struggle to meet the needs of all of its passengers.

The coming challengeIn June 2012, the University of Exeter released a study in the journal Energy and Environmental Science, that concluded that if the current food consumption patterns continue, the planet's food supply will be unable to meet the food needs of the 9.3 billion people who are expected to be living in 2050.

The researchers estimated that if the amount of meat consumed in the Standard American Diet (SAD) was reduced by about half, the projected food shortages would be largely neutralized.