Critical Reasoning

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. 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. if people consume less calories then they can be thin even with low metabolic rates
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. irrelevant
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. amount not discusses
D. Researchers have not yet determined whether the metabolic rates of formerly very overweight individuals can be accelerated by means of chemical agents. OUT OF SCOPE
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. Not even a hint let alone an assumption

Overwt people----const & low metabolism rate-----hence lose wt by dieting---
But burn less calr when wt reduced----so regain wt till original metabolism rate
This can be true when we assume that metabolism rate changes at particular wt---this is true for less overwt or thin people.

B is the answer choice that provides this assumption.
So I will go with B.

deepsok wrote:Overwt people----const & low metabolism rate-----hence lose wt by dieting---
But burn less calr when wt reduced----so regain wt till original metabolism rate
This can be true when we assume that metabolism rate changes at particular wt---this is true for less overwt or thin people.

B is the answer choice that provides this assumption.
So I will go with B.

no, this is wrong assumption you have made. The metabolism is relatively low of the people who are overweight. It is not stated neither assumed anywhere that metabolism varies as per weight.Furthermore, B goes way too far in stating about overweight people. Author has assumed anything about normal people.

Well I didnot like answer choice A because,it has words "relatively few"
I dont understand why assume that "only few people consume less calories".

Now,
In the argumenet,conclusion is about thin person (overwt peope have become thin now due to dieting)
So I like the answer choice B.

can anybody guide me to paraphrase conclusion and premise???
That will help me to validate my reasoning here.

Ozlemg wrote: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.

I received a PM about this CR.

Premise:
After very overweight people lose weight, they will burn significantly fewer calories at the new weight than do people whose weight is normally at that level.
Conclusion:
Such newly thin persons will, therefore, ultimately regain weight.

The assumption is WHAT MUST BE TRUE for the conclusion to be valid.
One approach is to apply the NEGATION TEST.
When the correct answer choice is negated, the conclusion will be invalidated.

A, negated:
Most very overweight people who have dieted down to a new weight...consume substantially fewer calories.
Here, newly thin people consume substantially fewer calories, invalidating the conclusion that these people will regain weight.
Since the negation of A invalidates the conclusion, A is the correct assumption: WHAT MUST BE TRUE for the conclusion to be valid.

The correct answer is A.

I have been asked to explain why C is incorrect.
C, negated:
The amount of calories that a person usually burns is NOT determined more by the amount consumed than by the current weight of the individual.
It is given as PREMISE that newly thin people BURN fewer calories.
A premise a FACT.
It cannot be invalidated.
Since the negation of C has no bearing on the conclusion but affects only the premise about calorie-burning, eliminate C.

The assumption here is they very few overweight people eat less, so most of them gain weight again. which is A
this is the assumption that the author used to conclude that obese people will gain weight again.
Thinking about it, if they don't eat more, or if more people dont eat substantially fewer calories, they will not gain weight

GMATGuruNY wrote:

Ozlemg wrote: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.

I received a PM about this CR.

Premise:
After very overweight people lose weight, they will burn significantly fewer calories at the new weight than do people whose weight is normally at that level.
Conclusion:
Such newly thin persons will, therefore, ultimately regain weight.

The assumption is WHAT MUST BE TRUE for the conclusion to be valid.
One approach is to apply the NEGATION TEST.
When the correct answer choice is negated, the conclusion will be invalidated.

A, negated:
Most very overweight people who have dieted down to a new weight...consume substantially fewer calories.
Here, newly thin people consume substantially fewer calories, invalidating the conclusion that these people will regain weight.
Since the negation of A invalidates the conclusion, A is the correct assumption: WHAT MUST BE TRUE for the conclusion to be valid.

The correct answer is A.

I have been asked to explain why C is incorrect.
C, negated:
The amount of calories that a person usually burns is NOT determined more by the amount consumed than by the current weight of the individual.
It is given as PREMISE that newly thin people BURN fewer calories.
A premise a FACT.
It cannot be invalidated.
Since the negation of C has no bearing on the conclusion but affects only the premise about calorie-burning, eliminate C.

need to find out an option that connects calories burnt to metabolic rate.

Only A does perform this function.

Hence, A.

Hi,

Could someone help to explain what "regain weight until their body size again matches their metabolic rate" exactly means?

Many thanks!

thuyduong91vnu wrote:Hi,

Could someone help to explain what "regain weight until their body size again matches their metabolic rate" exactly means?

Many thanks!

A low metabolic rate is typically associated with excess weight.
A high metabolic rate is typically associated with thinness.
But overweight people who become thin retain their low metabolic rate.
As a result, their low metabolic rate -- which is typically associated with excess weight -- does not match their newly developed thinness.
To compensate, they regain weight until they have the excess weight that is typically associated with a low metabolic rate.
In other words, they regain weight until their body size again matches their metabolic rate.