The ultimate equation that proves how many calories you should be eating
Everyone has been told that calorie-counting is the most effective way of lowering the scale and cutting the kilos.
An average woman is said to require about 2000 calories per day to maintain a certain weight, and 1500 calories to lose almost half a kilo of weight per week. The average male is similar, but slightly raised: he needs 2500 calories to maintain, and 2000 to lose that half-kilo of weight per week. The general rule of thumb deemed by society is to exercise more and eat less.
However, the math is not quite that simple. These rough estimations don’t consider numerous factors that would significantly sway the numbers: age, height, weight or activity levels. While you may think that frequent exercise is the best way to lose weight, it is not a transmutable technique for eating smart.
Fortunately, calorie counting doesn’t have to be a total guessing game. Instead of using exercise as a mere safety net for your eating habits, use this elementary equation to pinpoint exactly how many calories you need per day.
The calculation is called the Mifflin-St Jeor equation, a formula that has been shown to be the most accurate way of estimating calorie needs in numerous studies by the ADA (American Dietetic Association).
Getting an idea of your basal metabolic rate (BMR)
Begin by getting an idea of your basal metabolic rate (BMR).
Your body must breathe, blink, grow cells and keep your heart beating on a daily basis.
Staying alive isn’t an easy task, and it needs calories to do so. This number reflects an estimate of how many calories you would burn if you were to be hypothetically resting in a sedentary state for 24 hours.
In other words, it represents the minimum amount of energy mandated to keep your body barely functioning, i.e. breathing and pumping blood.
For men, the equation is as follows: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5. The equation is slightly different for women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161.
For example, if you were a 63kg, 30-year-old, 167cm woman, your BMR calculation would look like this: 10 x (63.5) + 6.25 x (167.6) – 5 x (30) – 161 = 1,371.5.
Use this BMR number as the foundational reference point for safe weight loss. According to the Academy of Nutrition and Dietetics, your calories should never dip below 1,200. Doing so could mean your muscle mass starts decreasing, which means you won’t have enough energy to fuel daily activities.
Now that we’ve figured out the bare minimum of calories your body demands, we can’t forget to account for the actual things you do throughout the day that burn these calories; walking to work, playing sports, doing yoga, or even watching TV all strip away those units of energy you consume.
An easy way to do so is via this interactive calculator from the United States Department of Agriculture (USDA) that incorporates your activity level and BMR to give you an estimate of how much you should eat in order to maintain your current weight.
The BMR rule of thumb
If you want to do it yourself, here is a general map to follow. The final number is the recommended calorie consumption per day – tailored just for you:
BMR x 1.2 for low intensity activities and leisure activities (primarily sedentary)
BMR x 1.375 for light exercise (leisurely walking for 30-50 minutes 3-4 days/week, golfing, house chores)
BMR x 1.55 for moderate exercise 3-5 days per week (60-70% MHR for 30-60 minutes/session)
BMR x 1.725 for active individuals (exercising 6-7 days/week at moderate to high intensity (70-85% MHR) for 45-60 minutes/session)
BMR x 1.9 for the extremely active individuals (engaged in heavy/intense exercise like heavy manual labor, heavy lifting, endurance athletes, and competitive team sports athletes 6-7 days/week for 90 + minutes/session)
After all that, it’s important to note that this number isn’t necessarily something you should streamline your collective focus into. Although this does stand as the ideal formula to use as a guideline, weight loss boils down to more than just a number. Living your healthiest life doesn’t equate to shedding kilos, and obsessively counting calories can spiral one into an overly compulsive diet with dangerous downfalls.
The induced stress can actually raise your cortisol levels, making it even harder for you to lose weight.
In essence, be conscious of your healthy caloric intake, but it’s wiser to concentrate on what you’re eating than how much. Also, don’t forget the huge impact that WHEN you eat can have on your waistline.
Your body knows best what it wants, so if it’s asking for fuel, indulge it, don’t spoil it.
Written by Hana Hong. This article first appeared in Reader’s Digest. For more of what you love from the world’s best-loved magazine, here’s our best subscription offer.