Q15 - A person's dietary consumption

[esmail.dana]

Hi,

I got this answer correct by process of elimination, but I was just wondering if anyone could walk through why (C) is the correct answer choice.

Thank you!

[maryadkins]

SC rises proportionate to F&C Consumption until the threshold, then SC rises gradually (which means we don't know how it matches up--"gradually" is ambiguous).

This threshold is 1/4 of F&C Consumption in the average diet.

So in the average diet, only 1/4 of people's F&C Consumption is proportionate to their SC level. That means for 1/4 of their consumption, we know how to measure SC level, and for 3/4 of their F&C Cons., we don't.

If we cut the F&C Cons. of the average diet in half, we're still above the threshold, which was 1/4 of the average diet (and is now 1/2 of the new diet). So for the rest, we don't know how to measure SC level.

Tricky question! Hope this helps.

[chocolatebunny]

I correctly picked C as the answer for this question. but I'm wondering why A is wrong. The stimulus says - Serum cholestrol levels rise proportionately to increased cholestrol and fat consumption" so then why can't the threshold be lowered by lowering the dietary consumption of cholestrol and fat?

[marshal_of_grey]

I correctly picked C as the answer for this question. but I'm wondering why A is wrong. The stimulus says - Serum cholestrol levels rise proportionately to increased cholestrol and fat consumption" so then why can't the threshold be lowered by lowering the dietary consumption of cholestrol and fat?

The threshold is an objective physiological fact. Lowering the dietary consumption of cholesterol and fat may put you under the threshold, but the threshold is fixed.

[robinzhang7]

I correctly picked C as the answer for this question. but I'm wondering why A is wrong. The stimulus says - Serum cholestrol levels rise proportionately to increased cholestrol and fat consumption" so then why can't the threshold be lowered by lowering the dietary consumption of cholestrol and fat?

The threshold is an objective physiological fact. Lowering the dietary consumption of cholesterol and fat may put you under the threshold, but the threshold is fixed.

The threshold is NOT fixed. Look at how the threshold is calculated: Threshold = 1/4 consumption of F&C in today's avg diet. Thus, if everyone in North America decides to participate in Weight Watchers then the threshold will decrease to a lower level, however, still remaining at 1/4 the avg F&C level.

This leads me to my questions concerning answer choices (A) and (C).
Firstly, (A) has merit because, as I explained above, if EVERYONE or VAST NUMBER OF PEOPLE went on lean diets, then the threshold would be lowered due to the much lower AVERAGE consumption level.

(C) I think C is also correct because the stimulus says that F&C levels are simply "IMPORTANT factors" meaning that there could be/are other factors involved in determining the serum cholesterol level.

Mary's way also works perfectly.

Could a Geek check my work?

Thanks!

[rinagoldfield]

Hi Robinzhang7,

Thanks for your analysis. The threshold IS actually fixed. It’s offered as a biological fact. SC rises proportionally with F&C consumption to a certain point (the threshold), at which point it stops rising directly with F&C. The threshold happens to be ¼ of North American diets, but that stat isn’t how the threshold is calculated.

By way of (made-up) analogy:

Humans need X grams of carbohydrate per day to survive
Most Americans eat 2X grams of carbohydrate per day.

^The amount humans need here is biologically fixed, not dependent on its relationship with American consumption. The same is true of the SC threshold vis-à-vis North American diets.

Best,
Rina