Introduction:
The basal metabolic rate (BMR) is known to be the minimum level of energy one needs to completely sustain in order to perform any vital functions of the body that is of the organ systems like breathing, digestion, and circulation. These, as we know are the essential bodily functions that are involuntary or occur beyond one’s control. The BMR/basal metabolic rate is primarily determined by the thyroid hormones that is the T3 and T4 hormones that primarily correlate to the thyroid stimulating hormone (TSH) and the cellular metabolism.
For most individuals, as one understands it in general terms, BMR is just a number that gets considered when one looks forward to losing weight or when one needs to know if one is trying to lose weight the healthy way. But it is much more when one wants to lose weight in a healthy manner. BMR is also a term that is used interchangeably or synonymously by many with the term RMR (resting metabolic rate), these are slightly different because RMR takes small or light movements of the individual as well into account.
What Is the Formula for Basal Metabolic Rate?
It is essential to note that the key to weight loss is a higher metabolic rate. All of the calories one would be burning in an average day is called the total daily energy expenditure (TDEE).
The basal metabolic rate is in fact one of the components of the total daily energy expenditure / TDEE. According to dieticians and nutrition experts, the way to lose weight in a healthy way should be such that if one can increase the BMR and thus in turn the TDEE, one would be in fact burning much more calories that way.
Though there are several major formulas suggested for calculating the BMR, an online calculator would be the simplest way to know what the BMR is. The common formula that is used by many nutrition experts to estimate BMR is the revised Harris-Benedict Formula:
In this formula that is used to calculate BMR, the point to note is that the formulas are different for men and women. This is also because this formula has been revised since they had been originally created. These popular formulas for calculating BMR are hence known currently as the "revised Harris-Benedict BMR equations".
- For Calculating BMR in a Male: 66.47 + (6.24 x weight in pounds) + (12.7 x height in inches) - (6.75 x age in years).
- For Calculating BMR in a Female: 65.51 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years).
When one uses these formulas for calculation, the weight should be estimated only in kilograms, and the height should be estimated in centimeters. One can also do the conversion to these measurements if one uses pounds and inches usually. Based on the lifestyle whether it is a sedentary, active, highly active, or athletic type, the registered dietician or the fitness coach will guide one to lose weight or gain weight based on one’s needs.
What Are the Factors that Influence the BMR of the Body?
In many situations, the BMR may be either temporarily affected or can undergo an eventual change with the change in the systemic health status. For example, say one is eating spicy foods suddenly or one has gone out in freezy weather, then temporarily one’s body would be undergoing a change in the BMR to compensate for the situational changes. In the long term, the factors that influence BMR are enlisted below and explained:
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Age: BMR usually tends to decrease considerably with age. This means that individuals would need to adjust their diet needs as they age older in order to avoid weight gain (because the metabolism gets slowed down as well).
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Weight: While heavier individuals have a higher rate of BMR, individuals with a lean or moderate physique tend to have low BMR.
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Height: The taller an individual is, the more mass would be proportional as well which directly influences the individual BMR. One’s height compared to one’s weight (the body mass index / BMI) is one more factor that also determines how much fat-free or fat-filled mass one has, which influences the BMR.
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Sex: Men usually have a much higher BMR in comparison to women owing to their higher body muscle mass as well as bone density.
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Genetics: Genetics could play one of the most influential factors in influencing BMR. Familial inheritance and genetics are often the reasons behind an individual's higher or lower BMR in the long term.
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Body Composition: Muscle mass as we know definitely expends more energy in comparison to fat mass. The higher the muscle mass, the higher will be one’s BMR. One’s body composition hence determines the BMR directly.
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Menopause Phase in Women: Women who go through the menopausal phase experience a significantly lower BMR during this phase, which means that the number of calories one would be burning is also less.
Other factors include the level of physical activity, metabolism, gut microbiome, and any existing health conditions or medications that one might be taking. Of all these factors, one can take steps to change their weight and body composition. So, if one desires to change the BMR, the first step would be to increase muscle.
Conclusion:
Several factors would possibly decrease the basal metabolic rate ranging from stress and lack of sleep to hormonal fluctuations, systemic diseases, and lack of a nutrient-rich diet. It is essential to hence eat healthy and practice a healthy lifestyle to boost the metabolic rate and sustain a healthy weight. Remember that losing weight the healthy way is, according to most nutrition experts all about losing the empty calories or the calories that one may be overdosing on through the course of a day. Simply put, it is all about the difference between the number of calories one burns and the number of calories one eats. When there is an imbalance in this caloric intake and one tends to consume more calories through the diet, burning out fewer calories in a day, would make one prone to putting on weight.
