need one more help

tyghbn

Researchers have found that when very overweight people, who tend to have relatively low metabolic rates, lose weight primarily through dieting, their metabolisms generally remain unchanged. They will thus burn significantly fewer calories at the new weight than do people whose weight is normally at that level. Such newly thin persons will, therefore, ultimately regain weight until their body size again matches their metabolic rate. The conclusion of the argument above depends on which of the following assumptions?
(A) Relatively few very overweight people who have dieted down to a new weight tend to continue to consume substantially fewer calories than do people whose normal weight is at that level.
(B) The metabolisms of people who are usually not overweight are much more able to vary than the metabolisms of people who have been very overweight.
(C) The amount of calories that a person usually burns in a day is determined more by the amount that is consumed that day than by the current weight of the individual.
(D) Researchers have not yet determined whether the metabolic rates of formerly very overweight individuals can be accelerated by means of chemical agents.
(E) Because of the constancy of their metabolic rates, people who are at their usual weight normally have as much difficulty gaining weight as they do losing it.


A is correct and why??

dansy

题干说那些超重的人新陈代谢的速率低，他们减肥是通过控制饮食来的，而他们新陈代谢的速率没有变。他们消耗的能量比正常体重的人消耗的要少的多。结论是这些超重的人减肥之后最终还是会变回到原来的重量，去与他的新陈代谢速率匹配。


这里有一个吸收和消耗的过程。新陈代谢的速率就是两者之间的平衡关系。答案A说大部分减肥的超重者吃的比正常体重者吃的多。只有这样，减肥的超重者才会基于他的低的新陈代谢速率，而继续增重。如果他吃的比正常体重的人少的话，即使是较低的新陈代谢速率，他也不一定会继续增重。

mariezhu

这种人新陈代谢率小，也就是代谢掉的东西少，



如果减完肥，还是keep the diet，那么代谢的虽少，但毕竟吃的也少，不会胖回去，


可是如果恢复原来的吃法，那么代谢的少，吸收的多，就慢慢又胖回去了。


题中结论是他们会胖回去，那么assumption就是他们没有继续保持cosume substantially fewer calories

[此贴子已经被作者于2004-3-30 11:21:29编辑过]

tyghbn

thanks guys, very articulate...