There are different kinds of cholesterol, and the first cut that people made at this were saying that there are things called HDL and LDL, which is high-density lipoproteins and low-density lipoproteins, the LDL.

胆固醇分为许多种,人们分离胆固醇时,最早得到的馏分是HDL和LDL,HDL即高密度脂蛋白,LDL即低密度脂蛋白

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选