I don’t believe in counting calories in order to restrict caloric intake. Rather I promote caloric awareness in the effort to get people to realize that they usually don’t eat enough food, not that they eat too much.
Calculating your Basal Metabolic Rate (BMR) is quite simple. Here’s the formula.
- Convert weight in pounds to kilograms by dividing by 2.2.
- Convert height in inches to centimeters by multiplying by 2.54.
- Plug in kilograms and centimeters where appropriate in the following formulas. The numbers that result the calculations are the calories that you need in a day to maintain current body weight with little or no exercise.
- Daily Resting Energy Expenditure Formula for Males
- 66 + (13.7 X kilograms) + (5.0 X centimeters) – (6.8 X years)
- Daily Resting Energy Expenditure Formula for Females
- 665 + (9.6 X kilograms) + (1.85 X centimeters) – (4.7 X years)
Let’s use the example of a 38-year old woman who stands 5’ 3” and weighs 125-pounds. Here are the calculations.
- 665 + 559 + 296 =1520
- 1520 – 179 = 1341 needed per day just to maintain without any additional energy expenditure.
Note the emphasis that 1341 calories are need just to maintain the status quo if this woman were just to sit around doing nothing during her waking hours. To approximate the true daily caloric requirement taking into account activity level we can use the Harris-Benedict Formula, which applies a factor to the BMR. Here are the factors according to activity level.
- Sedentary = BMR X 1.2 (little or no exercise, desk job)
- Lightly active = BMR X 1.375 (light exercise/sports 1-3 days/wk)
- Moderately active = BMR X 1.55 (moderate exercise/sports 3-5 days/wk)
- Very active = BMR X 1.725 (hard exercise/sports 6-7 days/wk)
- Extra active = BMR X 1.9 (hard daily exercise/sports & physical job or 2X day training, i.e marathon, contest etc.)
Using the above example, apply the Moderately Active factor to the BMR of this working mother of three children who trains at least as hard as specified in this category.
- 1341 x 1.55 = 2078
I can guarantee that 99% of the women who fit the description of the example do not get anywhere near 2100 calories per day. I’ll also wager that of these women, most are engaged in a regular struggle to lose 5-10-pounds, and do so by restricting rather than adding calories. And keep in mind that these calculations under estimate the requirements for people are either very fit or very fat. So calculate your BMR and gain an appreciation for how many calories are needed in a day to fuel your body.