Weight Loss And Calorie Counting
To start losing weight right away, you’ll need to know the scientific principles behind weight loss. Let’s start by learning how many calories you actually need each day.
You would need to know your basal metabolic rate or BMR. This tells you how many calories your body needs to perform its daily functions. Your BMR informs you how many calories is necessary for survival and what is needed to carry out the natural processes of the body. You would, however, require more calories than your BMR suggests if you are a very active person. Your Total Energy Expendure (TEE) is the total of your BMR and number of calories that you burn doing daily activities.
You can determine an adequate number of calories needed for weight loss by using various formulas. The most widely used is the Harris-Benedict formula, which considers your age, gender, height, and current weight to come up with a suitable number of calories.
Here is an example of this formula in action:
Men: BMR = 66 + (13.7 X wt in kg) + (5 X ht in cm) – (6.8 X age in years)
Women: BMR = 655 + (9.6 X wt in kg) + (1.8 X ht in cm) – (4.7 X age in years)
(For calculation purposes, 1 inch = 2.54 cm and 1 kilogram = 2.2 lbs.)
Example:
A 35 year old female who stands 5’4” (163 cm) tall and weighs 130 pounds (59 kilos) would use the following equation:
655 + 566 + 293 – 165 = 1,349.
The woman in the example would need 1,349 calories a day just to lie around in bed and keep her organs functioning. If that number seems small, it’s because we haven’t yet taken this woman’s activity level into consideration.
Activity multipliers work as such:
Sedentary people (office jobs, no real exercise) multiply their BMR by 1.2. Lightly active people (exercise 1 – 3 times per week) multiply their BMR by 1.35.Moderately active people (exercise 4 – 5 times per week) multiply their BMR by 1.55. Highly active people (sports or hard exercise most days) multiply their BMR by 1.725. Extremely active people (hard exercise every day) multiply their BMR by 1.9.
Let’s revisit the woman in our example. Let’s imagine she has a desk job and is inactive for most of the week. Although she is performing at such a minimum activity level, she still would burn some calories driving to and from work and walking around, typing and moving around at her desk.
For her to just maintain her current weight, her BMR which is 1349, has to be multiplied by her sedentary activity level,which is 1.2. This means that she needs 1 619 calories to maintain her weight. If she started exercising just 2 or 3 days each week, her daily calorie requirement would increase to 1,821.
So how do these numbers help you lose weight? In order to get rid of one pound of fat a week, one has to burn off 3500 more calories than you consume. So, for the woman in the example to decrease her weight by 1 pound a week, she would have to eat 1 119 calories a day if she is sedentary, or 1321 if mildly active.
This shows us that it is easier to lose weight through a combination of physical activity and diet, than through diet alone.