Whether you are trying to lose weight or gain weight, or just trying to maintain your weight, you need to understand how much calories do you burn on a daily basis. Which means knowing your Basal Metabolic Rate is important as it clears the need for loss of calories for the body. Scientifically weight loss or gain is not rocket science and if you do not have any major ailments then weight loss or gain is just a game of calories consumed.
For weight loss or weight gain, one needs to understand two major terms, the BMR and TDEE.
Basal Metabolic Rate
Basal Metabolic Rate (BMR) is the total number of calories that the body needs to perform life-sustaining basic functions. They basal functions include breathing, cell production, circulation protein synthesis, ion transport and nutrient processing. BMR can be calculated using a mathematical formula.
For men: BMR = 88.362 + (4.799 x HT) + (13.397 x WT) + (5.677 x AGE)
For women: BMR = 447.593 + (3.098 x HT) + (9.247 x WT) – (4.330 x AGE)
HT = height (in centimetres), WT= weight (in kilograms), AGE= age (in years)
So basically your body burns a lot of calories even when you are doing nothing and just breathing.
When one spends some time in doing a physical activity then the total calories spent during the day inclusive of your Basal Metabolic Rate is called as TDEE. Your TDEE would depend on your daily activity. Once can use an activity calorie calculator or tracker to understand how many calories they burn a day.
Many exercise guides use the terms Basal Metabolic Rate (BMR) and Resting Metabolic Rate (RMR) interchangeably. These two are similar but there is a slight difference in the definition of BMR and RMR that is helpful to understand.
Resting Metabolic Rate
Resting Metabolic Rate (RMR): – it is a measurement of the number of calories the body burns when at rest. This is usually measured in the morning before you eat or exercise and after a full night of restful sleep.
It can be seen that the definitions of BMR and RMR are almost identical. Your resting metabolic rate should be an accurate estimate of your basal metabolic rate. Since the terms are similar many exercise guides use both terms to describe the same thing.
Using Basal Metabolic Rate to determine your calorie goal
Reducing the number of calories than your body needs to function will result in weight loss. To lose 1 pound (0.45kg) a week, reduce your daily intake by 500 calories. As the Basal Metabolic Rate provides the number of calories your body uses for basic functions, there are other factors that affect calorie needs, including activity and the thermic effect of food (is the amount of energy used above the basal metabolic rate due to the cost of processing food for use and storage.), also account for part of your total calorie needs.
To calculate the calories you need to maintain your current weight, multiply your Basal Metabolic Rate by an activity factor. If you do not exercise and have a desk job, your activity factor is 1.2. If you exercise one to three days a week, your activity factor is 1.375. If you exercise three to five days a week, your activity factor is 1.55. If you’re involved in sports and exercise six to seven days a week, your activity factor is 1.725. If you’re training for a marathon or have a physically demanding job, your activity factor is 1.9.
Changing Your Basal Metabolic Rate for Weight Loss
As you lose weight your Basal Metabolic Rate decreases, which means you need to eat even less as your weight continues to drop down to grams. Loss of muscle may be partly responsible for some of the decrease in your Basal Metabolic Rate. With strength-training exercises to build muscle, you may be able to offset some changes in your Basal Metabolic Rate. Free weights, resistance bands or body resistance exercises such as squats, sit-ups and push-ups can be used for working on your muscles. If you’re not sure where to begin, consult a fitness professional to help design an individualised exercise plan for you.
Here are some factors that affect Basal Metabolic Rate
as weight, height, and surface area increase metabolic rate increases.
muscle tissue has a higher metabolic activity than the fat tissue. Metabolic rate increases as the lean muscle mass increases.
The basal metabolic rate (BMR) averages 5 to 10 percent higher in men than in women. This happens mostly because women generally possess more body fat and less muscle mass than men of similar size.
A decrease in lean muscle mass during adulthood results in a slow, steady decline of roughly 0 3 percent per year in Basal Metabolic Rate after the age of about 30. This can be largely avoided by strength training throughout adulthood.
Climate and body temperature:
The Basal Metabolic Rate of people in tropical climates is generally 5 to 20 percent higher than their counterparts living in more temperate areas because it takes energy to keep the body cool. Exercise performed in hot weather also imposes an additional metabolic load.