Harris Benedict Equation: what does it consist of?

Although knowing where our food comes from, and adopting healthy dietary habits is more important than counting calories, the Harris Benedict Equation can give us important information.
Harris Benedict Equation: what does it consist of?

Last update: 01 June, 2020

The Harris Benedict Equation serves to approximately calculate an individual’s basal metabolic rate based on their weight, height, and age. This result is multiplied by a series of factors related to how physically active the person is. This way, it’s possible to estimate the daily calories that an individual consumes, and propose a diet according to their goals.

The Harris Benedict Equation

According to an article published in the American Journal of Critical Care, the Harris Benedict Equation corresponds to the following mathematical formula:

  • For men:

TMB = (10 x weight in kilograms) + (6.25 x height in centimeters) – (5 x age in years) + 5

  • For women:

TMB = (10 x weight in kilograms) + (6.25 x height in centimeters) – (5 x age in years) – 161

From here you can find the number of calories that the individual spends just by being alive, even in a complete state of rest. To calculate a person’s daily energy expenditure, it’s necessary to quantify their physical activity and add this expenditure to the result of the Harris Benedict Equation.

However, we should mention that these indirect methods are only indicative. Unfortunately, there’s no operational way to accurately know an individual’s metabolic expenditure. Therefore, we must use equations as a guide to calculate an approximation with a certain error rate.

A woman weighing herself to calculate her metabolic basal rate with the Harris Benedict Equation

The usefulness of the equation

Experts used this formula for many years to develop dietary guidelines. This way, they intended to make an approximation of the individual’s expense to prepare a diet according to their energy needs.

However, it’s currently an obsolete method. For starters, it has a fairly wide margin of error. On the other hand, current weight-loss diets focus on healthy habits, not counting calories.

Therefore, including patterns such as intermittent fasting involve a caloric restriction that will lead to weight loss in most scenarios. All of this without the need to be mathematically precise.

On the other hand, the equation’s imprecision isn’t the only thing that makes it an unreliable method. It’s also very hard to calculate exactly the energy expenditure that derives from physical exercise.

Current diets don’t count calories

Nowadays, people are choosing healthy lifestyle habits. For example, the mere fact of reducing our sugar intake has positive consequences for our health, and it can be a great way to help during a weight loss process.

As a matter of fact, there’s a study from 2016 that positively correlates sugar consumption with the risk of obesity. However, this relationship isn’t so evident in the case of fats, even though they’re denser in calories.

It’s totally possible to have a successful mathematical approach to weight loss. However, it’s more practical and beneficial for our health to focus on where the calories are coming from when dieting.

Gaining or losing weight has more components than the strictly numerical ones. Factors such as the quality of our gut flora, previous pathologies, epigenetics, or metabolic status can influence weight loss positively or negatively.

A woman measutring her waist in front of the mirror

For those reasons, it’s much more effective to adopt healthy lifestyle habits rather than become obsessed with numbers. We must be aware that this habit can increase the predisposition of suffering from eating disorders.

Instead of the Harris Benedict Equation, it’s best to eat well

To lose weight, having a healthy eating pattern is much more effective than counting calories. Therefore, replacing the consumption of processed foods with fresh products, and including daily physical activity sessions in our lives are two successful strategies.

Similarly, intermittent fasting protocols often bring good results as well. Studying the individual’s microbiota or the quality of their circadian hormonal rhythms can make the difference between achieving or not achieving the established goals.

Lastly, there are certain supplements that can help improve weight loss processes. Caffeine, HMB, creatine, or melatonin are ergogenic aids that can facilitate this process when we use them under the supervision of a professional.

Finally, don’t forget that proper body weight is almost synonymous with health. Therefore, you should take care of your diet, and put yourself in the hands of a specialist in case you have doubts.

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  • Ferreira Picolo M., Fabiane Lago A., Gonçalves Menegueti M., Antonio Nicolini E., et al., Harris Benedict equation and resting energy expenditure estimates in critically III ventilator patients. Am J Crit Care, 2016. 25 (1): 21-9.
  • Stanhope KL., Sugar consumption, metabolic disease and obesity: the state of the controversy. Crit Rev Clin Lab Sci, 2016. 53 (1): 52-67.