In that process there is a metabolic engine at work, and some people have an efficient engine so that the calories in get banked in the fat, other people have an inefficient engine, that is the calories get wasted as body heat and things like that, and they tend not to gain weight.

这过程中人体内有个工作着的代谢引擎,有些人的代谢引擎效率很高,热量便转化为脂肪储存起来,另一些人的效率低下,能量就以体温等形式被浪费了,因此他们就不容易发胖

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选