Final answer:
Tall, thin individuals often have a higher BMR due to a greater body surface area, which contributes to increased energy expenditure to maintain body temperature. Additionally, a lower body fat percentage and increased lean mass, often through exercise, can lead to a higher BMR.
Step-by-step explanation:
Basal Metabolic Rate (BMR) and Physical Characteristics
BMR, or Basal Metabolic Rate, is an indicator of how much energy your body needs to maintain basic functions while at rest. One of the factors that can affect BMR is body surface area. According to research, taller and thinner individuals generally have a higher BMR compared to those who are shorter with the same weight. This difference is because a greater body surface area increases heat loss, and the body must work harder to maintain core temperature, thus consuming more energy. Additionally, a lower body fat percentage also correlates with a higher BMR. Since fat tissue requires less energy to maintain than lean tissue, individuals with more lean tissue (often characterized by their height and low body fat) will consequently have a higher BMR.
Regarding weight, while heavier individuals have a higher absolute BMR due to the energy required to maintain a larger body mass, when we consider BMR relative to body weight, taller individuals often have a higher BMR because of their greater surface area relative to their weight. This principle is similar across different species, where smaller animals tend to have higher BMRs relative to their body weight due to their proportionally larger surface area.
It's also essential to note the influence of exercise on BMR. Regular physical activity builds lean tissue, which is more metabolically active than fat tissue. This increase in lean mass can contribute to a higher metabolic rate, even during rest, which in turn can contribute to the differences observed in BMR among individuals.