Which of the following activity factors corresponds to normal activity levels?

The activity factor representing normal activity levels typically falls within the range of 1.5 to 1.75. This range is designed to account for individuals who engage in regular daily activities, including walking, household chores, and recreational activities, without being classified as either sedentary or highly active.

This range is beneficial for calculating the energy expenditure of populations that maintain a moderate lifestyle, where daily physical activity is sufficient to promote health but not so intense as to push energy needs to higher levels, which would be reflected in the choices with higher factors.

Using a lower factor, such as 1.3, would suggest a largely sedentary lifestyle, which does not accurately represent those with normal activity levels. In contrast, higher factors like 1.7 or above imply increased physical activity, often associated with athletes or those with rigorous exercise routines. Hence, the 1.5 to 1.75 range is most appropriate for individuals who are moderately active, aligning well with typical daily life activities without excess.