What is basal metabolic rate and how is it measured?
24th September, 2020
When we talk about weight loss diets we always mention basal metabolism and the metabolic rate. These may seem like complex concepts, but in fact they are super easy to explain and essential to understanding why it is so difficult for you to lose weight, or conversely, why it’s so easy.
What is basal metabolic rate?
Basal metabolism is the energy your body needs to survive while carrying out the basic functions such as breathing, pumping the heart, filtering blood, synthesising hormones and blinking.
This is a basic energy expenditure and is ‘preset’, because even when you are at complete rest, your body continues to work. Think of it as the electricity a TV uses when it’s on standby.
Everyone’s metabolism is different however, and depends on several factors such as sex, age, height, weight and build. Metabolic rate increases all the way up to adulthood, stabilises, then starts to decrease from the 40s onwards.
Basal metabolic rate is a calculation of the minimum calories required by a person to carry out bodily functions on a daily basis.
How to calculate BMR
There are many formulas to calculate your BMR, but one of the most widely used around the world is the formula written by Harris Benedict in 1919, and revised by Mifflin and St. Joer in 1990.
MEN BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5
WOMEN BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161
Besides this calculation, a person’s calorie requirements will depend on the amount of exercise they get, because nobody spends all day on the sofa…well… maybe some do!
Remember that any form of exercise you do expends energy, from going downstairs to ironing or studying for an exam.
If you take into account all of the physical exercise you do, you can calculate your calorie requirements following this formula:
Little or no exercise = required daily calories = BMR x 1.2
Light exercise (1-3 days a week) = required daily calories = BMR x 1.375
Moderate exercise (3-5 days a week) = required daily calories = BMR x 1.55
Heavy exercise (6 days a week) = required daily calories = BMR x 1.725
Professional or extreme exercise = required daily calories = BMR x 1.9
You should also factor in whether your job is very active, or you spend all day sitting down, or when you arrive home you do all the housework, then spend 2 hours at the park chasing your kids around…
For this reason there are tables to show you your caloric expenditure per minute for a given activity, allowing you to add this to the total calories you need to consume per day.
Cleaning windows spends 0.061 (cal x kg of weight x minute).
If you weigh 60kg and clean the windows for 30 minutes you will spend 160 calories.
Ironing uses 0.063 (cal x kg x minute).
About 115 calories in 30 minutes.
Climbing stairs spends 0.254 (cal x kg x minute).
225 calories in just 15 minutes.
A farmer uses 0.098 (cal x kg x minute).
350 calories in 60 minutes (in an 8-hour day this equals 2800).
Tips to speed up your metabolism in a healthy way
If you’ve decided to look after yourself a bit more in order to reach your ideal weight, bear in mind that you must consume fewer calories than your body needs, so that this deficit translates into weight loss. However you can also try these ideas to speed up your metabolism and make your body spend more energy. As always, follow a balanced diet.
Eat breakfast every day
Increase your consumption of the type of protein and carbs that require more energy for their digestion, and reduce fats (especially saturated and trans fats).
Become a fan of herbal teas. For example green tea, which aids the oxidation of fats. They also help to flush out toxins and boost intestinal transit.
Consume omega 3, found in salmon, tuna, nuts…Apart from protecting your heart, they prevent leptin resistance, which will help you to lose weight.
Eat more often. If you avoid periods of fasting, your body spends more energy and doesn’t store it. Between meals, eat fruit, yogurt or nuts.
Do some exercise on a daily basis. It doesn’t need to be an extreme exercise, just something that combines aerobic activity with bodybuilding, to achieve the afterburn effect that sees you burn more calories even once you’ve stopped.
At awaken we want you to learn how to eat healthy and look after yourself with us. Give it a try!