BMR depends on:
**Core Concept**
The basal metabolic rate (BMR) is the amount of energy expended by the body at rest, representing the body's energy expenditure to maintain basic physiological functions. BMR is influenced by various factors, including age, sex, weight, and body composition.
**Why the Correct Answer is Right**
BMR is a function of the body's surface area, which is proportional to body weight. The Harris-Benedict equation is a widely used formula to estimate BMR, which takes into account sex, age, and weight. For men, BMR (in kcal/day) is calculated as 66 + (6.2 x weight in lbs) + (12.7 x height in inches) - (6.8 x age in years), while for women, it is 655 + (4.35 x weight in lbs) + (4.7 x height in inches) - (4.7 x age in years). This equation demonstrates that BMR is directly related to body weight.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as BMR does not directly depend on blood pressure.
* **Option B:** This option is incorrect as BMR is not a function of the body's temperature regulation.
* **Option C:** This option is incorrect as BMR is not a direct function of the body's surface area alone, but rather a function of the body's surface area and body weight.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that BMR is a critical component of energy balance, and any changes in BMR can impact overall energy expenditure and weight management.
**Correct Answer: D. Body weight**