Critical Reasoning

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?
"¢ Calorie restriction produces similar results in humans as it does in rats and mice.
"¢ 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.
"¢ Calorie intake is directly correlated to insulin level in moderately overweight individuals.
"¢ Individuals with low insulin levels are healthier than individuals with high insulin levels.
"¢ Some individuals in the study reduced their calorie intake by more than 25 percent.