Why Basal Metabolic Rate Matters in Weight Loss

Losing weight is hard, especially for people suffering from obesity and weight-related health conditions. It’s a common and costly struggle for many American adults, and for over 50% of the population considered obese and overweight, it’s an endless battle against cravings, hunger pangs, and the temptation to stray from healthy eating habits.

While there are many things you can do to help shed some pounds, one of the most critical concepts you should know is the basal metabolic rate (BMR). It refers to the number of calories your body burns at rest per day to keep your body functioning. Believe it or not, your BMR has a lot to do with how successful you are at losing weight.

In this post, we’ll take a look at what exactly BMR is, how to determine your BMR, and how you can use it to your advantage in achieving your goal weight and living a healthier life.

What is Basal Metabolic Rate?

Basal metabolic rate, sometimes called basal metabolism, is the rate at which your body burns calories throughout the day to provide energy for life-sustaining functions like breathing, digestion, and blood circulation. It estimates the minimum number of calories your body needs at resting state to sustain these functions. In other words, you are burning a certain number of calories, even if you just stayed in your bed the entire day.

Knowing your current BMR is one of the best ways to determine how many calories you should consume per day to maintain, lose, or even gain weight. Hence, it’s a good starting point whether you want to build lean muscle mass or reduce body fat.

What Determines Your Basal Metabolic Rate?

Basal metabolic rate accounts for around 60 to 70% of the total calories burned every day. But your BMR changes over time as you age and begin to lose lean body mass. Since muscle burns more calories than fat, the more muscle mass you have, the more energy you spend at rest, hence higher BMR.

However, it also depends on other physical characteristics unique to you, including:

  • age
  • sex
  • height
  • weight
  • body composition
  • genetic factors
  • health status

It should be noted that the total calories an individual burns to provide energy for basic body functions vary from person to person. It doesn’t include other ways your body uses calories for energy, like walking, talking, and eating, which is called the resting metabolic rate (RMR).

With this, experts recommend adding resistance training on top of your physical activity to increase muscle mass, lose weight, and improve body composition, which are some of the best ways to increase BMR.

What is the Difference between BMR and RMR?

People often use basal metabolic rate (BMR) and resting metabolic rate (RMR) interchangeably because of their similarities. Both can give you an idea of your overall metabolic rate, and they can also be used to represent how many calories you burn at rest in determining your total daily energy expenditure (TDEE). However, there is a minor difference between the two that you should be aware of.

We have already established that BMR estimates the number of calories your body requires to support the most basic functions mentioned above. RMR, on the other hand, is exactly that with the extra calories your body uses for low-effort daily activities, such as eating, drinking, and walking. In short, RMR also includes energy expended for non-exercise daily activities.

Based on their definitions, resting metabolic rate is a better reference to the number of calories required for your daily energy requirements or your typical energy expenditure, as it accounts for almost all of your basic daily activities. Since they are almost similar, some fitness and nutrition experts often use both terms to refer to the same thing. However, the term RMR is more commonly used in articles, books, and research studies.

How to Estimate Your Basal Metabolic Rate?

While knowing your BMR doesn’t directly contribute to weight loss, it can help adjust your daily calorie intake and exercise goals to maintain your current weight or reach your goal weight. However, experts suggest that accurate BMR calculations can only be done in the laboratory with highly controlled environmental conditions.

Instead, people can have an accurate estimate of their RMR through online calculators like this one from Omni Calculator. Most of the calculators available online are based on the Revised Harris-Benedict formula or the Mifflin St Jeor equation. Simply input your sex, age, height, and weight to get an estimate of your daily caloric needs or typical resting energy expenditure to maintain, lose, or gain weight.

How Many Calories Do You Need Every Day?

Once you have an estimate of your BMR or RMR, the next step is to determine your daily calorie needs based on your lifestyle. Your TDEE or the number of calories you burn per day during everyday activities and exercise can be calculated by multiplying a certain number to your BMR.

  • Sedentary – little to no exercise; BMR x 1.2
  • Slightly active – one to three days a week of light exercise; BMR x 1.375
  • Moderately active – three to five days a week of moderate exercise; BMR x 1.55
  • Active – six to seven days a week of intense exercise; BMR x 1.725
  • Very active – six to seven days a week of very intense exercise or you have a physically demanding job; BMR x 1.9

Based on the formula above, if your BMR is 1,530 calories/day and you have a moderately active lifestyle, your TDEE is around 2,370 calories. The recommended calorie intake for healthy adults who want to maintain their weight is 2,500 for men and 2,000 for women.

With an online weight loss planner like this one from the National Institutes of Health (NIH), you can determine your ideal daily calorie intake if you want to maintain or lose weight in a certain amount of time. From our example above, you need to consume around 2,400 calories per day to maintain your weight (60 kg) and around 1,900 calories per day to lose 5 kg in 3 months.

Lose Weight with Your Basal Metabolic Rate

If your goal is to lose weight, you need to take in fewer calories than what you burn. Depending on your BMR that is unique to you, you should aim for a daily calorie deficit of no more than 500 calories to promote steady and sustainable weight loss while still staying within your BMR.

With this, you can expect to lose around 0.5 to 1 kg (1 to 2 lbs) per week until you reach your desired weight, which is considered healthy and sustainable. Adding increased exercise in your daily physical activities can help you build muscle mass to boost your metabolism.

Our nutrition and fitness experts at Beltline Health are committed to helping thousands of our patients struggling with their weight and weight-related health conditions by providing professional advice and guidance in assessing each individual’s daily calorie needs, setting realistic short-term and long-term weight goals, and developing a simple weight loss plan to promote healthy eating habits and lifestyle choices.

Watch our free weight loss online seminar where we’ll go over the basics of weight loss and the different weight loss solutions we offer to help our patients lose weight and keep it off. For more information, click here to schedule a consultation with one of our health care professionals or call us at (470) 419-4380.


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