How Many Calories Do I Need to Lose Weight?

As many diets come and go, there seems to be the traditional approach that remains with a strong following. The basis for the traditional approach involves paying attention to what we eat in conjunction with a regime of physical activities.

It can be looked at as a basic equation made up of two things. The calories we take in via food minus the calories we burn through physical activity.

The first thing you should be able to calculate is the approximate amount of calories your body burns.

Before we go on to the theory, you can simply use the calories need to lose weight calculator to do the same thing.

Your Basal Metabolic Rate

This is the number required for the involuntary functions of your body such as breathing. There are formulas which calculate your BMR that are primarily determined by your age, sex, height and weight

BMR

English BMR Formula

Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)

Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in year)

Metric BMR Formula

Women: BMR = 655 + (9.6 x weight in kilos) + (1.8 x height in cm) - (4.7 x age in years)

Men: BMR = 66 + (13.7 x weight in kilos) + (5 x height in cm) - (6.8 x age in years)

For Example:

Male, 83 kilos, 181cm

BMR = 66 + (13.7 x 83) + (5 x 181) – (6.8 x 28)
BMR = 66 + 1137.1 + 905 – 190.4
BMR = 1917.7 calories

Total Daily Energy Expenditure

Total Daily Energy Expenditure is the total number that your body burns each day through activity. When you know how many you burn each day through physical activity, then you know the following:

  • How many calories you need each day to maintain your weight
  • How many calories you need each day to lose weight

It is often calculated using the Harris Benedict Equation which multiplies your daily BMR by an activity factor which you choose accordingly (See below).

Activity Factor

Your activity factor is a number determined from a scale based on how active you are on a daily basis.

  • Sedentary (little or no exercise, desk job) multiply BMR by 1.2
  • Lightly active (light exercise/sports 1-3 days per week) multiply your BMR by 1.375
  • Moderately active (moderate exercise/sports 3-5 days per week) multiply your BMR by 1.55
  • Heavily active (hard exercise/sports 6-7 days per week) multiply your BMR by 1.725

Total Daily Energy Expenditure = BMR x Activity Factor

My example = 1917 x 1.4 = 2683.8 calories

How does this help me lose weight?

Now that I know my Total Daily Energy Expenditure I know that a daily intake of this amount will help maintain my current weight.

In order to lose weight I know that I need to intake less calories then I burn. This is called a calorie deficit.

So given that my Total Daily Energy Expenditure is 2683.8calories, I might set my goal at a daily intake of 2183 calories, creating a 500 calorie energy deficit. If I burn energy daily at this rate, I can expect to lose roughly 1 pound in a week.

The American College of Sports Medicine suggests that 500 calories energy deficit is the number you should aim towards for weight loss.

Remember, study has shown that slow and steady weight loss is the way to go, as fast weight loss generally means gaining all the weight back even faster. Men should comsume at least 1800 calorie and 1200 calorie for woman.