Calorie restriction, a diet high in nutrients but low in calories, is

Question

Calorie restriction, a diet high in nutrients but low in calories, is known to prolong the life of rats and mice by preventing heart disease, cancer, diabetes, and other diseases. A six-month study of 48 moderately overweight people, who each reduced their calorie intake by at least 25 percent, demonstrated decreases in insulin levels and body temperature, with the greatest decrease observed in individuals with the greatest percentage change in their calorie intake. Low insulin level and body temperature are both considered signs of longevity, partly because an earlier study by other researchers found both traits in long-lived people.

If the above statements are true, they support which of the following inferences?

(A) Calorie restriction produces similar results in humans as it does in rats and mice.

(B) Humans who reduce their calorie intake by at least 25 percent on a long-term basis will live longer than they would have had they not done so.

(C) Calorie intake is directly correlated to insulin level in moderately overweight individuals.

(D) Individuals with low insulin levels are healthier than individuals with high insulin levels.

(E) Some individuals in the study reduced their calorie intake by more than 25 percent.

sayantanc2k · Accepted Answer

Identify the premise; identify the conclusion . Visualize a logic flow diagram (premise -----> conclusion).

Now consider the given option.

Does the option lie IN BETWEEN the premise and conclusion? Then it is an assumption (premise ------assumption----> conclusion). The assumption is a link between premise and conclusion.

Does the option lie AFTER the conclusion? Then it is an inference (premise -----> conclusion--------> inference). The inference follows from something (either premise, conclusion or other information) given in the passage.

Bunuel · Answer

OFFICIAL EXPLANATION

A. The passage states that calorie restriction in mice and rats prolongs life by preventing diseases. The human study had much more limited findings – that calorie restriction in moderately overweight humans decreases insulin levels and body temperature. While these traits are known to be associated with longevity, there are no data that link calorie restriction itself to prolonged human life. Additionally, calorie restriction may have other unstated effects, unrelated to longevity. There is no information in the passage that indicates whether these effects are the same in humans as in mice and rats. Finally, the use of the term "humans" is far too general; the study dealt only with moderately overweight humans and so any inference would need to be restricted to this subset of individuals.

B. While the passage indicates that certain traits known to be associated with longevity are found in moderately overweight humans who reduce their calorie intake, this is far removed from the conclusion that calorie intake will actually increase a human's lifespan. Additionally, the use of the term "humans" is far too general; the study dealt only with moderately overweight humans and so any inference would need to be restricted to this subset of individuals.

C. The study observed that individuals with the greatest percentage decrease in their calorie intake demonstrated the greatest decrease in insulin levels and body temperature. This shows a strong correlation between calorie intake and insulin levels. However, this correlation is not necessarily direct. It is possible that this correlation holds, but only up to a point. For example, it might be the case that any reduction in calorie intake over 50 percent does not result in any additional insulin level decreases. Moreover, the passage only draws this correlation for individuals with the greatest percent decrease in calorie intake. It is very possible that individuals with a relatively low decrease in calorie intake exhibit the exact same decrease in insulin levels as individuals with a moderate decrease in calorie intake.

(D) The study makes no reference to the health of individuals who reduce their calorie intake. It tries to draw some connection to the longevity of those individuals, but longevity is not the same as health. An individual could live a very long, unhealthy life.

(E) CORRECT.  The passage states that the greatest decrease in insulin levels was observed in individuals with the greatest percentage change in their calorie intake. This means that some individuals in the study reduced their calorie intake by a greater percentage than other individuals in the study. The passage also states that the study participants reduced their individual calorie intakes by "at least 25 percent." Thus, one can safely infer that there were some participants who reduced their calorie intake by more than 25 percent.

subhen · Answer

I will go with E as well.

a. Calorie restriction produces similar results in humans as it does in rats and mice. 
-Just because some of the results are similar we cannot inference that all results are similar.

b. Humans who reduce their calorie intake by at least 25 percent on a long-term basis will live longer than they would have had they not done so. 
- This is close. While from the argument it should be true. However we cannot make a blanket stmt for all human beings. There could be other reasons not mentioned in the argument why someone who has reduced calorie intake by atleast 25% could die earlier.

c. Calorie intake is directly correlated to insulin level in moderately overweight individuals. 
-Insulin level can also increase owing to other reasons not mentioned in the stmt.

d. Individuals with low insulin levels are healthier than individuals with high insulin levels. 
-Just because humans are likely to live longer does not gurantee that they will be healthier.

e. Some individuals in the study reduced their calorie intake by more than 25 percent.
- This is paraphrasing of the stmts already made in the argument and hence can be certainly infrenced.

sidbidus · Answer

I'll go with  (A). 

How can it be (E)???

Atleast 25 % does not mean necessarily greater than 25 % ..............may all the subjects reduced their calorie intake by exactly 25%.

ioiio · Answer

But it also says higher the calorie reduction better the results are. Doesnt that mean there were atleast a few people who had reduced their intake by greater than 25%

GMATaddict · Answer

I think I would go with (E), for it is the least disputable claim. The original info states that everyone reduced C-intake by at least 25%. However, greatest changes resulted with the greatest percentage change in C-intake. This implies that not everyone's C-intake reduction level was the same. & since a intake reduction of less than 25% is impossible, some individuals must have reduced C-intake by more than 25%.

AmritaSarkar89 · Answer

I always get confused between assumption and inference question. And specially in the heat of the examination I make this error continuously. Any lucid explanation or cheat sheet for the same.

ProfChaos · Answer

(A) Calorie restriction produces similar results in humans as it does in rats and mice.   -   INCORRECT  
"......prolong the life of rats and mice by preventing heart disease, cancer, diabetes, and other diseases."
".....48 moderately overweight people,...., demonstrated decreases in insulin levels and body temperature,"

(B) Humans who reduce their calorie intake by at least 25 percent on a long-term basis will live longer than they would have had they not done so.   -   INCORRECT  
Nothing has been said about people who dont change their diet

(C) Calorie intake is directly correlated to insulin level in moderately overweight individuals.   -   INCORRECT  
"Calorie restriction, a diet high in nutrients but low in calories" 
Not necessarily, it could be nutrients that helped with insulin levels or a combination of low calorie+high nutrients that helped

(D) Individuals with low insulin levels are healthier than individuals with high insulin levels.   -   INCORRECT  
"Low insulin level and body temperature are both considered signs of longevity,..."
Longevity is not same as healthy

(E) Some individuals in the study reduced their calorie intake by more than 25 percent.   -   CORRECT  
"...who each reduced their calorie intake by at least 25 percent..."
"the greatest decrease observed in individuals with the greatest percentage change in their calorie intake....."
>25% also done by some.

VerbalBot · Answer

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

Calorie restriction, a diet high in nutrients but low in calories, is

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Calorie restriction, a diet high in nutrients but low in calories, is

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards