Scientists first posed this question in the mid-1990s, after researchers came upon a chemical agent that in rodents seemed to reproduce many of caloric restriction's benefits.

科学家首次提出这个问题是在20世纪90年代中期。当时，研究人员偶然发现一种化学药剂，这种药剂在啮齿动物身上似乎可以发挥和热量限制相同的正面效果。