You are pushing down with the weight mg, and the floor has got to be pushing up with the mg, because the spring is not going anywhere.

你向下的作用力是重力 mg,然后地面向上的支持力也是 mg,因为弹簧现在根本没动

耶鲁公开课 - 基础物理课程节选

That little J shaped curve is explained primarily by cigarette smoking because that keeps weight down in people, it also makes people sick so that their weight gets low because of that, and it explains the high rates of the disease risk there.

这个小J形曲线主要是由吸烟引起的,因为吸烟一方面能让体重降低,另一方面也引起疾病,疾病让人们的体重下降,这也解释了这里的高患病风险

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选