Dr. Robert S. Lawrence

If everybody on the planet ate as much meat as Americans do, according to Dr. Robert Lawrence, the planet could only support a population of 2 to 3 billion people. That's because meat and other animal products take so much energy to produce. But reducing the amount of meat we eat to 75 grams daily (http://www.medscape.org/viewarticle/562956) could improve the planet's carrying capacity, mitigate the effects of climate change and improve population health, he said.