Which individual would be expected to have the highest basal metabolic rate?

• A. 25-year-old male who is 6' tall and weighs 200 pounds
• B. 40-year-old male who is 6' tall and weighs 210 pounds
• C. 30-year-old female who is 5'7" tall and weighs 200 pounds
• D. 50-year-old female who is 5'3" tall and weighs 120 pounds

Answer: (A)

Basal metabolic rate reflects the energy your body needs at rest to maintain basic physiological functions, and it rises with larger body size and more lean mass while aging tends to lower it. Men generally have higher BMR than women of the same size because they usually carry more muscle, which is metabolically active, and thus burn more calories at rest.

In this scenario, the younger man who is tall and weighs about 200 pounds would typically have the highest BMR because he combines substantial lean mass with youth, while the other man is older even though he is a bit heavier, and age reduces BMR over time. The two women have lower BMRs overall, especially the shorter, lighter, and older one, due to smaller body size and the sex difference in lean mass. So the individual with the highest BMR would be the younger man.