Using that same example and this equation, the female’s RMR would equal approximately 1,356 calories.Īt first, this error appears small (i.e., 55 calories), but extrapolated over a one-year period, it amounts to almost six pounds of energy or body weight.įurthermore, these formulas also imply that all individuals of the same gender, age, height and weight have the same RMR, a fact that is certainly not accurate.

Women: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161.

Men: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5.

The Mifflin-St Jeor equation, created in the 1990s, provided an alternative and more valid estimate of RMR (3). This is the energy needed daily to maintain normal physiological function.

Women: 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) - (4.330 × age in years)Īs an example, for a 38-year old female, who stands 5’6” (167.6 cm) and weighs 145 pounds (65.9 kg), her BMR or RMR would equal approximately 1,411 calories.

The revised H&B equations for males and females (2) are: Technically, BMR measures energy expenditure in a darkened room (reclining position) after eight hours of sleep and following a 12-hour fast whereas RMR measurements are less restrictive and reflect the body’s resting energy expenditure after an overnight fast. While it was intended to measure basal metabolic rate (BMR) or basal energy expenditure (BEE), they are used interchangeably with RMR. The Harris and Benedict (H&B) equation created in 1918 and amended in 1984 remains widely used today (1-2). Here’s an example of one online calculator you can use to find out your RMR: You can access these with calorie calculators on the Internet, an app or through wearable devices. Perhaps the most common methods utilized today are mathematical formulas. They measure this value with varying degrees of accuracy.

Indirect calorimetry measures oxygen utilization rates via gas analysis to calculate energy expenditure.Īlthough direct and indirect calorimetry provide accurate estimates of RMR, these techniques are expensive, time consuming and difficult to access.Īs a result, more accessible and affordable techniques that estimate RMR have been developed over the past 100 years. It is proportional to lean body mass and decreases approximately 0.01 kcal/min for each 1% increase in body fatness.ĭirect calorimetry measures the amount of heat produced by a subject enclosed within a small chamber to calculate energy expenditure.

RMR supports breathing, circulating blood, organ functions, and basic neurological functions. Resting metabolic rate is the total number of calories burned when your body is completely at rest. * Non-exercise Activity Thermogenesis: Energy expended for everything you do that does not include sleeping, eating, physical activity or exercise – ranges from simple standing to fidgeting and moving about.Ĭan we calculate our RMR? Can we influence it or is it predetermined? Let’s examine these questions more closely. The thermic effect of physical activity (TEPA): the energy of activity (e.g., exercise, physical activity) and non-exercise activity thermogenesis (NEAT).*.The thermic effect of food (TEF): the energy cost of chewing, swallowing, digesting, absorbing and storing food.Resting metabolic rate (RMR): the energy required to keep your body functioning at rest.Our TDEE is essentially comprised of three components: But for most of us, it refers to total daily energy expenditure and how it influences our energy in versus energy out equation. Scientific references to metabolism refer to the bodily processes needed to maintain life. Assessing Starvation States for Optimal RMR.But before we dive into RMR, let’s take a look at the components of total daily energy expenditure (TDEE). Our resting metabolic rate (RMR) plays a significant role in this, and it’s understandable why it garners so much attention. This is an outcome of enhanced caloric expenditure, increased lean body mass, greater fat utilization and overall weight loss. To the general public, boosting your metabolism is associated with the transformation from ‘fat-to-fit’ or ‘flab-to-fab’. As a nutrition coach or weight loss specialist, this is a topic you may get asked about from time to time. Mention the term ‘metabolism’ and it captures attention given how obsessed many of us have become over calories.

Breastfeeding bmr calculator