They use food frequency questionnaires, which I mentioned before, surveys, and then biological markers like blood tests of certain things to see how diet is related to health.

研究员还运用食物频率调查表,我之前曾提到过,各类调查以及生物标志物,像是血液检测等手段,来研究饮食与健康之间的关系

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

That means that a group of people who were identified and then re-measured every other year on -to getting blood tests and other biological markers, as well as doing assessments of their lifestyle behaviors and a number of other things.

就是说有一群特定的人,然后每隔几年,就要接受血液及其他生物学测试,还要对他们的生活方式等进行评估

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选