Final answer:
A 20-year old conditioned male athlete would most likely have the highest basal metabolic rate due to a combination of higher muscle mass, lower body fat percentage, and the metabolic demands of a younger age.
Step-by-step explanation:
The individual most likely to have the highest basal metabolic rate (BMR) or resting metabolic rate is a 20-year old conditioned male athlete. Factors influencing BMR include age, gender, body weight, muscle mass, and body fat percentage. Given that muscle mass has a significant impact on BMR and males generally have a greater muscle mass and lower body fat percentage than females, the male athlete would have a higher BMR. Additionally, weight also plays a role, with heavier weights generally leading to a higher BMR due to higher energy demands of a larger body mass, with the caveat that muscle mass is more metabolically active than fat tissue. Finally, since BMR decreases with age, a younger individual will typically have a higher BMR compared to an older one, all other conditions being equal.
Based on these factors:
- The 20-year old male athlete would likely have the highest BMR due to greater muscle mass and a lower body fat percentage.
- An individual's metabolic rate at rest, or BMR, accounts for about 75% of their daily energy expenditure. Athletes generally have a greater BMR because of their higher muscle mass.
- Body fat percentage and body surface area also influence BMR, with lower body fat and greater body surface area contributing to a higher BMR.