Buchanan believes, It's human nature to want more meat and dairy, and that will be very difficult to change.

VOA: standard.2010.06.04

Now there are challenges to a plant based diet which made eating meat important to humans in human history.

在人类历史上,以素食为主的饮食方式面临各种挑战,使得进食肉类变得重要

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选