The abbreviation bmr means basal metabolic rate. It describes the energy the body uses to keep functioning when it is at rest. This includes essential processes such as breathing, maintaining body temperature and keeping the heart beating. BMR is an important nutrition term because it helps explain why people need energy even when they are not exercising or completing physical tasks. For GCSE Food Preparation and Nutrition or WJEC Level 1/2 Hospitality and Catering, learn the definition carefully and use it accurately in explanations about energy needs.
What is basal metabolic rate?
Basal metabolic rate is the amount of energy the body needs to maintain its vital functions while at rest. Energy comes from food and is measured in units such as kilojoules or kilocalories. The body uses some of this energy simply to stay alive.
For example, even while a person is asleep, their body still needs energy to:
- keep the heart beating and blood circulating;
- support breathing;
- maintain a stable body temperature; and
- keep organs working.
This is why energy is needed before any additional activity, such as walking to school, playing sport or preparing food, is considered.
BMR and total energy needs
BMR is not the same as a person’s total daily energy requirement. Total energy needs also depend on physical activity and the energy used to process food. A person who is very active will usually need more energy overall than someone who is less active, even though both bodies use energy at rest.
A useful way to remember the difference is:
- BMR: energy used to keep the body functioning at rest.
- Total energy needs: energy for BMR plus everyday movement, exercise and other body processes.
Why is BMR useful in food studies?
BMR helps you understand that energy requirements are not identical for everyone. People have different bodies, lifestyles and levels of activity. Nutrition advice therefore needs to consider the individual rather than assuming that one energy intake suits everybody.
In an exam answer, do not just write that BMR is the energy a person uses. Make the answer precise by stating that it is the energy used to keep the body functioning at rest. The phrase “at rest” is essential because it separates BMR from energy used during movement and exercise.
Exam-ready retrieval checklist
- Can you write out BMR in full?
- Can you define it as energy used to keep the body functioning at rest?
- Can you give two examples of body functions that need this energy?
- Can you explain why BMR is different from total daily energy needs?
- Have you used the phrase “at rest” in your answer?
Definitions and assessment contexts can be updated. Check the relevant WJEC specification or AQA specification for the wording and context required by your course.