Metabolism is a term that’s widely used, especially in connection with gaining weight or losing it. But what does it really mean?
Put simply, metabolism is the sum of the chemical reactions that take place within each cell of your body that provide energy for vital processes in order to maintain life.
The rate at which your body uses up kilojoules (or energy) to carry out these vital metabolism functions is called the metabolic rate:
Your BMR can be influenced by many factors including your body size, age, gender, genetic predisposition, hormones and what you eat. The amount of exercise you do can have an effect as well.
It’s all to do with muscle. Compared to women, men’s bodies generally have more muscle and less fat which makes a difference to your BMR. While fat burns very few kilojoules, muscle is an active, ‘hungry’ tissue that uses up kilojoules even when you’re just sitting around.
Exercise increases the amount of muscle you have — and the more muscle you have, the faster your BMR will be. Exercise will generally help increase muscle. Studies show strength training (also known as resistance training or weight training) builds muscle more effectively and increases BMR.
Nutrient Reference Values: Dietary Energy
Bouchard C, Perusse L, Deriaz O, Despres JP, Tremblay A. Genetic influences on energy expenditure in humans. Critical reviews in food science and nutrition. 1993;33(4-5):345-50.
Cho S, Dietrich M, Brown CJ, Clark CA, Block G. The effect of breakfast type on total daily energy intake and body mass index: results from the Third National Health and Nutrition Examination Survey (NHANES III). Journal of the American College of Nutrition. 2003;22(4):296-302.
Dolezal BA, Potteiger JA. Concurrent resistance and endurance training influence basal metabolic rate in nondieting individuals. Journal of Applied Physiology. 1998;85(2):695-700.
Hensrud D. Slow metabolism: Is it to blame for weight gain? Rochester, MN: Mayo Foundation for Medical Education and Research (MFMER); [updated 2011 Aug 23; cited 2013 June 6]. Available from: http://www.mayoclinic.com.
Metabolism. Melbourne: Better Health Channel; [updated June 2011; cited 2013 June 6]. Available from: http://www.betterhealth.vic.gov.au.
What is metabolism? Tarzana, CA: Metabolic Institute of America (MIA); [cited 2013 June 6]. Available from: http://www.themetaboliccenter.com.
Last Updated: 6 June 2013
This information has been developed and reviewed for Bupa by health professionals. To the best of their knowledge it is current and based on reputable sources of medical research. It should be used as a guide only and should not be relied upon as a substitute for professional medical or other health professional advice.
Bupa Australia Pty Ltd makes no warranties or representations regarding the completeness or accuracy of the information. Bupa Australia is not liable for any loss or damage you suffer arising out of the use of or reliance on the information, except that which cannot be excluded by law. We recommend that you consult your doctor or other qualified health professional if you have questions or concerns about your health. For more details on how we produce our health content, visit the About our health information page.
Last published 31 October 2010