Basal metabolic rate

Definition

Basal Metabolic Rate (BMR) is the amount of energy expended while at rest in a neutrally temperate environment, in the post-absorptive state. It represents the minimum amount of energy required to keep your body functioning, including breathing and circulation.

5 Must Know Facts For Your Next Test

1. BMR accounts for about 60-75% of total daily energy expenditure in most people.
2. Factors affecting BMR include age, sex, genetic predisposition, body composition, and hormonal activity.
3. BMR can be measured using indirect calorimetry by assessing oxygen consumption and carbon dioxide production.
4. A higher muscle mass typically increases BMR because muscle tissue requires more energy to maintain than fat tissue.
5. BMR decreases with age due to loss of lean body mass and changes in hormonal activity.

Review Questions

• What percentage of total daily energy expenditure does BMR typically account for?
• Which factors can influence an individual's BMR?
• How is BMR commonly measured in a laboratory setting?

Related terms

Energy Expenditure: The total amount of energy used by the body in a given period, including basal metabolic rate, physical activity, and thermic effect of food.

Thermic Effect of Food: The increase in metabolic rate after ingestion of a meal due to the energy required for digestion, absorption, and disposal of ingested nutrients.

Calorimetry: The measurement of heat flow or heat production in various processes; used to determine metabolic rates by measuring oxygen consumption and carbon dioxide production.