Extremist followers of the paleo diet who believe and actively preach to others that foods like grains, dairy, legumes and sugar are responsible for the majority of global health issues and should be avoided like the plague for optimal health, performance and longevity.
Like any good cult follower they will push any information that supports their beliefs, whilst turning a blind eye to any information that doesn't.
Peter: Why is Joe eating satay chicken without any rice?
Paul: Haven't you heard? He's a paleotard - he thinks grains are responsible for 9/11.