BASAL METABOLIC RATE
Is it possible to lose weight if you stay in bed all the time and do nothing? Sure, as long as you eat just enough to stay alive. The energy needed for our body to function at rest, while doing nothing, is called basal metabolic rate or BMR. It is the energy needed for our heart, brain, kidneys and other organs to operate and keep us alive. Why is it important to know our basal metabolic rate? We are all different and we spend different amount of food to provide energy for our basic functions. Once we know our basal metabolic rate, we can also calculate how much we need to eat in order to keep healthy weight. Basal metabolic rate is calculated while we are at rest, when we do not spend energy for any activity except for the basic functions for our survival. Basal metabolic rate depends on our sex, age, weight and height. Once we know how much energy (food) we need to survive, we can also calculate how much calories from food we need per day, depending on our lifestyle, kind of work we do and the amount of physical exercise. Formula for calculating BMR There are many automatic calculators of basal metabolic rate available online, but if you want to know how it is calculated, here is the formula, different for women and men: Women: BMR = 655 + (4.35x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years) Men: BMR = 66 + (6.23x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years) Of course, this formula works for most people but not all. One variable that is not taken into consideration is lean body mass. Muscles spend more energy for survival than fat tissue, so people with lean, mean bodies need more energy to survive. That also means that obese people, who have much more fat tissues than muscle mass, need less energy to live, and have lower basal metabolic rate. So, now you understand why some of your friends can eat anything and stay lean. Not only that they spend a lot of calories while exercising and building all those muscles, but muscles themselves burn calories even while doing nothing. If you ever needed a reminder why exercising is so important, this is just another one of many. Basal metabolic rate can be calculated using the formula based on sex, age, weight and height, and the obtained result is fairly accurate. But, if you need more exact information, you can get your doctor to do a proper test. BMR is normally measured in a clinical environment in ideal conditions, because it can be affected by the environment temperature, by previously consumed food and the level of stress a person is under.
Basal metabolic rate (BMR) refers to the minimum amount of energy — in the form of calories — that your body requires to complete its normal functions, such as breathing, breaking down food, and keeping your heart and brain working. Age, gender, weight, and physical activity directly effect on basal metabolic rate.
BMR varies from person to person and increases with your amount of muscle tissue.
Exercising increases your BMR, and it can stay raised after 30 minutes of moderate physical activity. Many people’s BMR stays increased for approximately 48 hours following exercise.
HOW TO CALCULATE YOUR BMR (AND WHY IT MATTERS)
Think you need to run a marathon just to burn off breakfast, lunch and dinner? Think again. The human body requires a significant amount of energy (i.e. calories) just to function regularly. Each day, your body must breathe, blink, circulate blood, control body temperature, grow new cells, support brain and nerve activity and contract muscles. Staying alive is hard work, people! The amount of energy (in the form of calories) that the body needs to function while resting for 24 hours is known as the basal metabolic rate, or BMR. This number of calories reflects how much energy your body requires to support vital body functions if, hypothetically, you were resting in bed for an entire day. In fact, your BMR is the single largest component (upwards of 60 percent) of your total energy burned each day.
While you can’t magically change your BMR right away, knowing your personal number, how it’s calculated, and which factors most influence your metabolism, can help you use this data point to create a smarter strategy for weight loss (or maintenance).
BMR: YOUR BASIC BURN
To most accurately calculate BMR, an expert takes measurements of carbon dioxide and oxygen analysis after a subject has fasted for 12 hours and has had eight hours of sleep. However, a rough estimation of this data is possible using the Mifflin-St. Jeor equation, a formula introduced in 1990. Since it’s proven to be more accurate than previous BMR formulas, the Mifflin-St. Jeor equation is now considered the standard when it comes to calculating BMR.
MIFFLIN ST. JEOR EQUATION
FOR MEN: BMR = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5
FOR WOMEN: BMR = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) – 161
“You’ll want to use a BMR as a rough estimate to set your basic needs,” says Dr. Jennifer Sacheck, Ph.D, an associate professor of nutrition at Tufts University and co-author of Thinner This Year. She notes that this won’t vary too much for a male or female of the same age and body weight. Why the emphasis on weight, height, age and gender?
Weight and height: “The more mass you have, the more fuel you need to sustain larger organs,” notes Dr. Sacheck, explaining why heavier and taller individuals have a higher BMR. When you lose weight, your BMR decreases and you require fewer calories per day. In contrast, when you gain dense, heavier muscle, your BMR will increase.
Age: Metabolic rate decreases as you age because muscle mass declines by five to 10 percent each decade after the age of 30. Luckily, it’s not a certain fate for the over-30 crowd. “We can mitigate that when we’re engaged in strength training,” says Dr. Sacheck. She recommends circuit training that incorporates full-body resistance exercises (think lunges, squats, core work on a balance ball). “Strength training individual muscle groups in isolation won’t be as effective in strengthening your body for daily movement that always incorporates a mix of muscle groups,” she says.
Gender: Since body composition (ratios of lean muscle, bone and fat) differ between men and women, research shows a woman’s BMR is typically around five to 10 percent lower than a man’s.
WHAT IS CONSIDERED A GOOD METABOLIC RATE?
To understand what is considered a good metabolic rate, we need to understand what is metabolism in the context of diet and weight loss. Metabolism is the name of a complex biochemical process by which the body turns food into energy, as well as for the body repairs. It also stores fat to be used in the future. The rate of metabolism is important in the sense that if we have a faster metabolism, we are able to burn calories more efficiently and less storage amount of fat.
When the rate of metabolism is slow, we also burn calories slowly and tend to store more calories as fat. So, to put it very simply, the metabolic rate is the efficiency with which our organization can perform these basic metabolic we stay healthy and in shape.
The metabolic rate of our body is the amount that we need to burn calories to allow the body to function optimally and maintain our organs and tissues in good condition. Normally, it takes up 60% of our caloric intake. Thus, when someone is very heavy, it will need more calories to fuel his body. What happens with the other 40% of the calories we consume? It is used to generate the extra energy we need to carry out other activities – depending on the type of physical activity should be our body every day.
Although there are several factors that determine our metabolic rate, as genetic factors, age, sex, level of activity, muscle to fat and the ratio of our eating habits, the bottom line to keep a good metabolic rate is to do regular exercise such as The more exercise you do, the greater will be your metabolic rate.
As mentioned above, metabolism is a series of complex biochemical reactions. In carrying out these functions properly, the body needs enough vitamins and nutrients. The best way to provide good nutrition for proper metabolism is to follow a balanced diet.
So how can you increase your metabolic rate and become more healthy? It is important to remember that different weight loss pills and supplements you can just to get the right metabolic rate. Metabolic rates can be calculated based on the size, weight and other factors. The first step to finding the right
metabolic rate is, how many calories you will need all of your plan daily energy expenditure. This is also called the TDEE (total daily energy expenditure).
This is the total number of calories per day, including the number of calories you burn during physical activity. It is also known by another name: “maintenance”. Thus, knowing your TDEE gives you a starting point from which you can begin to make adjustments in your diet, as well as calorie expenditure, or your plan for the year.
According to exercise physiologists William McArdle, Frank Katch, the average level of maintenance for women in the United States is 2000-2100 calories per day and the average for men is 2700-2900 per day. However, these are only averages and individual levels can vary considerably for athletes or even people very active.
Harris-Benedict equation is the way people have been calculating their Basal Metabolic Rate since 1919. Although opinions differ as to its accuracy, we must take into account many factors if you were to find it more accurately, as the level of activity, genetics, etc.