In simple terms, metabolism is a vital process in which the body converts the food and beverages that we consume from our diet into energy to fuel our body on a daily basis. This energy is essential for powering “basic” bodily functions (such as digestion and absorption of nutrients in our intestines, respiration, our heartbeat, circulation of blood through our vasculature, etc.), physiological pathways complex actions in our cells and tissues (eg, RNA transcription into various proteins, DNA synthesis, neural signals in our brain, etc.) and physical actions that require more energy (such as physical activity, immune responses, and healing).
Metabolism and metabolic rate are closely related. Metabolic rate can be broken down into three different components: resting metabolic rate (also known as resting energy expenditure or REE), thermogenesis, and energy burned during physical activity. REE refers to the amount of energy (ie calories) burned to keep all those “basic” physiological functions running when the body is at rest. REE makes up the majority of our total daily energy expenditure or use.
Thermogenesis describes the process of heat generation (the main product of metabolism) that occurs as a result of food intake and the activation of brown adipose (fat) tissue and supports the energy balance of the entire body. The third and final way we expend energy (ie burn calories) is through physical activity, which includes any daily movement we do, no matter how intense.
Daily metabolism and metabolic health are critical to promoting not only healthy weight and body composition, but also overall health and wellness. There are many variables that influence the health and efficiency of our body’s metabolism and metabolic rate, including age, body composition, muscle mass, biological sex, thyroid health, physical activity, dietary patterns and even our genetics and epigenetics.
.
