Question

If height, weight, and physical activity level are held constant, energy requirements ______ as an adult ages.

1) increase
2) decrease
3) remain the same
4) cannot be determined

Answer 1

Energy requirements decrease as an adult ages due to a reduction in Basal Metabolic Rate (BMR) and lean muscle mass, leading to less engagement in physical activity and further decreasing BMR.

Step-by-step explanation:

If height, weight, and physical activity level are held constant, energy requirements decrease as an adult ages. Basal Metabolic Rate (BMR) is known to reduce with age.

After the age of 20, it drops by about 2 percent per decade. This decline can be attributed to changes in body composition, such as reduced lean muscle mass.

A particularly significant drop in muscle mass and metabolic rate occurs between the ages of 50 and 70, which tends to limit the engagement in physical activity, leading to a cycle of further muscle loss and reduced metabolism.