Final answer:
The metabolic rate is the energy used by the body for all activities, while the basal metabolic rate (BMR) measures energy use at rest in a controlled environment. The BMR reflects the body's minimum energy needs and is affected by various personal factors. Exercise and dietary habits can influence both metabolic rates.
Step-by-step explanation:
The metabolic rate refers to the rate at which the body uses energy from food to sustain various life processes and physical activities. This measurement considers energy expenditure under various conditions and includes energy used during activities and digestion. In contrast, the basal metabolic rate (BMR) specifically measures the rate of energy expenditure at rest in a controlled environment, which accounts for the majority of an individual's total energy expenditure. If a person has not fasted or rested for at least 12 hours, one would calculate the metabolic rate rather than the BMR. BMR is affected by factors such as age, gender, body weight, and muscle mass.
The body adjusts its BMR in response to prolonged periods of over-eating or under-eating, and exercise can raise the metabolic rate by increasing both heat transfer and work output. It is important to note, however, that these processes are not in perfect thermal equilibrium due to the complex nature of living systems. By understanding these rates, individuals can better understand their body's energy needs and how they change with different lifestyle factors and activities.