Earlier animal studies showed that emotional or mental tension around birth affects methylation of the genes.

VOA: special.2009.11.24

So this diet, although it's processed by a company and sold for people doing animal studies, it more or less mimics what these animals might be eating under natural conditions.

尽管这些食物经过商业加工,并用于动物科学研究,但会尽可能的模拟,实验动物在自然环境下的饮食

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选