It turns out very difficult to study this in a lab.

事实证明,很难对此进行实验室研究

耶鲁公开课 - 心理学导论课程节选

Now in the case of The Framingham Study they did bi-annual assessments, every two years brought people into the lab and got very careful measures on them, so a lot of what we initially knew about diet and health, smoking and health, and other things came from The Framingham Heart Study.

弗明汉研究每两年做一次评估,每两年在实验室里对研究对象,进行十分仔细的检测,我们对饮食与健康,吸烟与健康以及其他的了解,最初都来自于弗明汉心脏研究

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选