I could not find a thread for this question; Therefore, I am posting the question here.

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.

OA is E, My doubt is that the argument states that "who each reduced their calorie intake by at least 25 percent" - There could be a case where all the participants reduced the intake by 25 percent exactly (i.e no one over 25 percent; this situation would satisfy the "at least 25 percent restriction) - In this case however, E would not hold...

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.




This case cannot happen.

If you read the portion in the stem that I've coloured, you'll see that there the greatest decrease was observed in individuals with the greatest percentage change in their calorie intake. This simply implies that there are a few people who's reduction in calorie consumption has been greater than 25%, else there would be no variation (greatest decrease).

Does this help?

good explanation, Gokul..

_________________
Tim Sanders
Manhattan GMAT Instructor

but don't you think E is an assumption derive the conclusion

i felt C should be the answer
can some help me through this

That's pretty much what you're looking for. If one of the answers seems so obvious that it basically restates the premises, that is the appropriate answer for a conclusion question..

_________________
Tim Sanders
Manhattan GMAT Instructor