Final answer:
The basal metabolic rate (BMR) accounts for about 70% to 75% of our total daily energy output, covering the energy required for basic bodily functions while at rest.
Step-by-step explanation:
The basal metabolic rate (BMR) accounts for about 70% to approximately 75% of our total daily energy expenditure. The BMR measures energy used by the body for basic functions such as the heart rate, respiration, and kidney function when at rest.
A significant portion of this energy goes to the liver and spleen, followed by the brain. Factors like age, gender, total body weight, and muscle mass affect an individual's BMR, with athletes typically having a higher BMR due to more muscle mass.