If we defined food differently: that it's something that nurtures the body, something found in nature, something that doesn't harm the environment-- there are a number of criteria one can apply to define a food-- then we might come up with a different definition than this, but this is the way the nutrition field generally looks at it.

如果我们给出不同的定义,滋养身体的物质,在自然界找到的物质,不会威胁到身体的物质,有很多标准可以拿出来定义食物,我们也许可以就此重新进行定义,但这就是营养学看待食物的方式

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选