A new weight-loss drug causes the loss of body fat in all patients who

Question

A new weight-loss drug causes the loss of body fat in all patients who take the drug. In those same subjects, however, the drug also causes the loss of moderate quantities of lean body mass, where “lean body mass” refers to all body mass other than body fat.

Which of the following statements can be properly inferred from the information in the passage above?

(A) Patients taking the new weight-loss drug will not necessarily experience a decrease in their overall percentage of body fat.

(B) The body weight of patients taking the new weight-loss drug will not necessarily decrease.

(C) The new weight-loss drug contains no chemical that exclusively targets the body’s fat cells.

(D) Users of the new weight-loss drug should exercise in order to maintain their current levels of lean body mass.

(E) The new drug catalyzes the loss of body fat and the loss of lean body mass via similar mechanisms.

parker · Accepted Answer

For an inference question, try to stick as close to the given premises as you can-- any jump in logic must be fully justified. With that in mind, attack the choices:

Choice (A) uses one of those wishy washy phrases that can be hard to argue with:  "not necessarily."   Maybe people who take the drug will decrease their percentage of body fat, maybe not. Another phrase that should set off mental alarm bells here is "overall percentage"--I'm with Gryphon here. We've all of a sudden shifted from a discussion of absolute quantities (mass) in the argument to relative quantities (percentage). Look at this concrete example:

Bob weighs  200 pounds , 20 lbs of which is body fat. Bob's mass is therefore  10%  (20/200) body fat.

He takes the drug and loses 1 pound of body fat, AND 
9 pounds of lean muscle mass. He has lost a total of 10 pounds, so weighs  190 pounds , 19 pounds of which are body fat. He is still  10%  (19/190) body fat. This is NOT a decrease in overall percentage of body fat.

BUT what about sridar's suggestion that the word " moderate " implies that the person loses more fat than lean body mass? In real life, this might be a perfectly reasonable assumption to make-- on the GMAT, however, AVOID making assumptions unless you absolutely have to. Even if you weren't convinced, leave choice A for now and look at the others.

Choice (B) also uses  "not necessarily" --but here you can disprove it clearly. If the body's mass is composed  entirely  of body fat and lean body mass, and  both  decrease, then the person's weight WILL necessarily decrease. Eliminate.

Nothing is mentioned in the argument about the chemical composition of the drug, or any kind of targeting. Just because the drug causes loss of body fat doesn't mean it  targets  fat cells. Maybe it targets something else and the effect on fat cells is a side effect. (Look at the runaway success of Latisse, which was a glaucoma medication that happened to grow eyelashes, and now is a blockbuster vanity drug.) Choice (C) is out.

I couldn't put it any more succinctly than Gryphon did regarding choices (D) an (E), so won't try here. They're out too, for the reasons listed in the above post.

Despite sridar's very reasonable reservations about the word "moderate"-- the other choices have large fatal errors, and what "moderate" means is never laid out in the argument. A is the last choice left standing.

Gryphon · Answer

IMO A.

Premise 1: Patients will lose body fat
Premise 2: Patients will also lose lean body mass (defined as everything that isn't fat)
A: Takes into account both premises and recognizes that percentage of body fat may remain unchanged even if person loses fat. (Absolutes vs. Percentages)
B: People will lose weight if they take the drug.
C: Also a contender, but the chemicals in the drug are beyond the scope of the question...IMO
D: Exercise is never discussed and hence beyond the scope of the question
E: This is largely an assumption because what catalyzes the loss of body fat and lean muscle is never discussed and also beyond the scope of the qeusiton

seekmba · Answer

A for me.

Total fat --> 40%
Body Mass --> 60%

After taking the drug, both body fat and body mass decrease.

So, when taking both together, the body fat has not decreased much.

sridhar · Answer

Hi all. I went for C.
The reason why I thought A is incorrect is because, the argument never mentions that the drug drains both the fat and the lean body mass in similar proportions. It says "the drug also causes the loss of  moderate quantities  of lean body mass" Hence, the fat reduction is higher than the "lean body mass" reduction..

C mentions that "there is no chemical that affects only the body's fat cells", which IMO is correct..

Share your thoughts guys..

Gryphon · Answer

A is correct because it takes into account the fact that a person is losing both fat and lean muscle mass, but you don't know in which quantities so taking the drug will not necessarily result in a reduction in body fat.

tingle15 · Answer

I picked C first... But after reading parker's explanation of overall percentage I am convinced with option A. Thanks Parker

craky · Answer

I wanted to click A without reading other answers ... but I did it and clicked A anyway -- now thinking, if I were in real gmat test - would it be worth it to save 30 sec. but not to be certain about other answers?

Kristaincarry · Answer

Such kind of drug or nicotine or pill's are harmful for few time after take drug lot more unwanted causes are increases under the specialist take such kind of prescription. Either than Regular diet take healthy nutrition changing unhealthy eating behaviors regular exercise regular cardio,skipping options to reach your fitness goals.

WesleyRamon · Answer

Eating less and moving more are the basics of weight loss that lasts. For some people, prescription weight loss drugs may help.

You'll still need to focus on diet and exercise while taking these drugs, and they're not for everyone.

Doctors usually prescribe them only if your BMI is 30 or higher, or if it's at least 27 and you have a condition that may be related to your weight, like type 2 diabetes or high blood pressure.

Here's what you should know about four of the most common prescription weight loss drugs: orlistat, Belviq, phentermine, and Qsymia.

Before you get a weight loss drug prescription, tell your doctor about your medical history. That includes any allergies or other conditions you have; medicines or supplements you take (even if they're herbal or natural); and whether you're pregnant, breastfeeding, or planning to get pregnant soon.

chesstitans · Answer

B,D,E are all out.
C is wrong b/c of "fat CELLS"
A is left.

This question has the word "all" that appears 3 times: "all patients", "those same subjects", "all other mass other than fat"

Hussain110 · Answer

hi  GMATNinjaTwo ,  mikemcgarry .
Could you please look into this?
Option A states that fat will not melt necessarily. but the passage does mention that fat will melt, with no exceptions stated.
Option C is more apt which brings a new element into picture, the chemicals and yes we can infer that from the passage, although not stated directly and that is what inferences are all about...
Is my understanding correct?

chesstitans · Answer

there is no information in the passage about chemical and fat CELLS.
by the way, how you tag name of other members in your post?

Hussain110 · Answer

Yes...exactly,there is no info about new chemicals, but that is what inferences are about. Options for inferences may introduce new elements, right?

P.S: You use @ProfileName to tag someone.

chesstitans · Answer

first, thanks for showing me the way to tag the name of a member.
Next, an inference has nothing to do with a new information, but an assumption often does. 
Oh Gosh, you really need to work on the inference question b/c such type of question is the main type in reading comprehensive in gmat. 
It is not hard to do inference questions in reading, but in CR, inference questions are hard. The point is an answer for an inference question must be always true based on information from the passage.

Hussain110 · Answer

chesstitans 
Ok..now tell me what makes you believe that option A is correct? Doesn't the passage say that the subject causes the loss of body fat(paraphrase: will lose body fat). But the option A states that they will not "necessarily" lose body fat!! How correct is this?
 I will be happy to stand corrected.

chesstitans · Answer

A is a common pattern in gmat b/c A concerns with the amount vs the percentage.
Clearly, in A, both the amount of fat and amount of non-fat decrease. For example, the total body mass is 10, fat is 6; the percentage is 60%. Now, fat is reduced to 3, and body mass is now half => percentage is still 60%. 
The other way to check whether A is truly right is to use POE method. That is, all wrong choices will be eliminated, and A is left.

Sreyoshi007 · Answer

Official Explanation  given my Manhattan Prep :

A properly inferred conclusion must be arrived at by necessary logical deductions, without any additional assumptions. Thus, the correct answer to this problem must be a necessary logical consequence of the statements in the passage.

(A) Correct. The passage states that patients taking the drug will experience losses of both body fat and lean mass, but does not state the relative amounts in which the two components of weight will be lost. In order to ascertain whether the subjects’ body fat percentage will go down, we need to know two ratios: the patients’ original ratio of fat to lean mass, and the ratio of fat lost to lean mass lost. Without definite figures for either of these ratios, the patients could lose fat and lean mass at relative rates that would either increase or decrease their percentages of body fat.

(B) The passage states that all patients taking the drug experience losses of both body fat and lean mass. Per the passage, these are the only two components of the subjects’ body weight, so, if the subjects experience losses in both components, then they must lose weight overall.

(C) The loss of lean mass does not imply that the drug cannot contain a chemical that targets the body’s fat cells exclusively. For instance, the drug could contain such a chemical along with other chemicals (perhaps necessary for other reasons, such as proper digestion or transport) that cause the losses in lean mass.

(D) Nothing in the passage is pertinent to the issue of preventing the loss of lean mass from the drug, so no such conclusion is justified.

(E) No information about the mechanism by which the drug catalyzes fat and lean-mass losses is presented in the passage, so no such conclusion is justified.

The correct answer is A.

NeoNguyen1989 · Answer

IMO A.

body fat's weight declines, body mass's weight declines and thereby perhaps the ratio of the body fat's weight over the body mass' weight might remain the same. Assume that now the body fat's weight is 40kg and the body mass's weight is 60kg => the ratio of body fat over body mass is 2/3. If the body fat's weight declines by 10kg and the body mass's weight declines by 15kg => the ratio is 30/45 = 2/3

VerbalBot · Answer

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A new weight-loss drug causes the loss of body fat in all patients who

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