Q22 - A long term health study

[dtangie23]

Can we please go over this problem? Thanks.

[bbirdwell]

First, identify the two points at odds.

Some studies = weight gain --> health problems and lower life expectancy

This study = for these people, weight gain of 1 lb/yr --> live longer than peers who maintained weight

The question is, why did the ones who gained weight live longer?

(A) proportion of weight? no effect.
(B) lose weight = good for health. not what we want.
(C) smokers are skinnier and have shorter life spans! this provides a potential reason why the ones who maintained their relatively lower weight had shorter life spans.
(D) no effect.
(E) opposite of what we want.

[jardinsouslapluie5]

I felt the answer choice (C) is a big jump to connect studied group and smokers. They said, "these people TEND to" which we have to think those people are smokers...
Big assumption, no?
But, if it has more possibility than other answer choices, it's okay?

[timmydoeslsat]

I felt the answer choice (C) is a big jump to connect studied group and smokers. They said, "these people TEND to" which we have to think those people are smokers...
Big assumption, no?
But, if it has more possibility than other answer choices, it's okay?

The questions stem asks us which one of the following would help to resolve the conflict?

If these people were smokers, that would help us to understand the discrepancy between it being the case that weight gain is associated with lower life expectancy and the people in this study that gained more weight than others lived longer.

This would be telling us that smokers tend to be leaner. So this is introducing the idea that those that did not gain the weight were smokers and that this was the reason why it appears the weight gain was beneficial to longevity, but it actually was not. It was really just a bad sample to compare.

[hall.briandavis]

The paradox seems to be:
1) it is healthy to gain .5-1 lb of weight each year
2) studies also suggest gaining weight tends to be asociated with other health problems.

Just because a smoker is leaner than non-smoker, that doesn't preclude them from not gaining weight as they get older. They could be leaner than non-smokers, but still gaining .5-1 lb a year. This therefore does not address the paradox as it pertains to gaining weight. It still does not explain why gaining weight is paradoxal (as oppossed to merely being leaner)

At best it would explain the paradox if the language referenced being heavier, as opposed to gaining weight...

But clearly I am wrong because that is not the answer choice. Can someone help me with my reasoning error.

[Mab6q]

Should we spent a lot of time reviewing this question. It's really not a great paradox question in my opinion because the answer choices have so many gaps.


C. Obviously we don't know if they were smokers, but more importantly we don't know if eating more makes them lives longer: correlation not causation.

[terpsfball09]

I feel like "C" is way too specific. I don't get how we're supposed to connect that most of the people in the study who showed the negative results were all (or for the most part) smokers.

[ohthatpatrick]

People are hating on (C) (and this question) because (C) doesn't come close to PROVING that smoking is why the leaner people in this study died early.

True!

But your task in Strengthen / Weaken / Resolve / Explain is never to prove anything. You're just doing SOMETHING to help or hurt our understanding of what's going on.

The question stem says most helps.

Well, (B), (D), and (E) seem to move in the opposite direction (they make it seem like less weight/calories/cholesterol = better .... more weight = worse).

(A) does nothing because nothing in there connects to life expectancy.

So (C) wins ... even though it does almost nothing, it alerts us to the possibility that maybe the leaner people in this study were smokers, and therefore maybe their surprising lack of longevity is really explained by smoking.

Sure, it's just a hypothesis, a story. But prior to reading (C), we didn't even have that.

A previous poster was unnerved by correlation vs. causality.

You don't have to think about any of this as causal. You could just be trying to figure out how these correlations possibly harmonize.

Other studies:
weight gain correlates with lower life expectancy

This study:
weight gain correlates with longer life expectancy

Correct answer:
nonsmoking correlates with weight gain AND longer life expectancy

So (C) suggests that "this study" might harmonize comfortably with the other studies' correlation, if we control for smoking.

Hope this helps.