Metabolism is the combination of all the chemical processes that allow an organism to sustain life. For humans, this includes conversion of energy from food into energy for life-sustaining tasks such as breathing, circulating blood, building and repairing cells, digesting food, and eliminating waste.

The minimum amount of energy needed to carry out these basic processes while an organism is fasting and at rest is known as the basal metabolic rate, or BMR, which can be calculated using a variety of online calculators that take into account an individual’s height, weight, age, and sex. BMR is often referred to as resting metabolic rate, or RMR. Total energy expenditure (TEE) is a combination of BMR, plus energy used for physical activities and energy used to digest food (known as dietary thermogenesis). For sedentary adults, BMR accounts for about 50% to 70% of total energy output, dietary thermogenesis for 10% to 15%, and physical activity for the remaining 20% to 30%.

Read more...