The Simple Math Calculation That Has a Major Impact on Weight Loss

When trying to lose weight, it's common to focus solely on the calories we take in and those we burn. But how do we even figure out what exactly we are burning? It's not as if we want to walk around all day wearing a heart rate monitor. Enter total daily energy expenditure, TDEE for short.

"Very simply, TDEE is the total number of calories you burn each day," says Tanya Becker, cofounder and chief creative officer of Physique 57. Though everyone's TDEE varies, with factors like genetics, age, gender, and weight playing a role, it's still a great tool to use as a barometer for success.

"To get a general sense of what your individual TDEE might be, start by looking at your basal metabolic rate (BMR), your activity level, and the food you eat," says Dr. Philip Goglia, celebrity nutritionist and cofounder of G-Plan, the first online nutrition platform based on a user's metabolic body type. The basic formula for calculating your TDEE is pretty simple.

"Your BMR is essentially the number of calories your body needs to do its basic functions like breathing and digesting food," says Dr. Goglia. To find your resting BMR, divide your weight by 2.26, multiply that number by 24, and round off to a whole number.

Example: Weight: 130 lbs./2.26 x 24 = a resting BMR of 1,380 calories

"Using the above example, if a female woman weighs 130 pounds, her body would need a minimum of 1,380 calories to complete basic functions," says Dr. Goglia. Next you need to take your activity level into account. Whether it is walking, grocery shopping, or intense exercise, all of these activities raise your daily caloric expenditure since they require additional energy. "This is known as your ABMR (active basal metabolic rate). To find your ABMR on a sedentary lightly active day, take your BMR and multiply by it either 1.1 for females or 1.15 for males," says Dr. Goglia.

As your activity level increases, so will the number used to calculate your ABMR. While the science is not exact, there are loads of handy online calculators that can help with this. "Keep in mind that the activity factor you choose is just a starting point and not an exact value of your energy expenditure," says Dr. Goglia. As a guide, Dr. Goglia recommends that active women calculate their BMR against 1.25 and very active women use a number of 1.45 to figure out their ABMR.

For more context, know that certain workouts can burn much more than being in an "active" TDEE category indicates. "Resistance and strength-training workouts help create more lean muscle mass. Muscle burns more than fat, allowing you to burn calories around the clock, even after your workout!" says Becker. The bottom line with TDEE is that it's a best estimate that gives you a baseline to work from.

If you want to get even deeper into determining your TDEE, it's important to know that the food you eat also plays a role — albeit small. Essentially, our bodies use energy to digest food, and certain foods need more energy than others. Protein takes the most energy for the body to digest, followed by fat, and then carbs. "It is known as the thermic effect of food, which is the number of calories burned in the process of eating and digesting food. This only counts for a small percentage of TDEE, and therefore, not an essential part of the equation," says Dr. Goglia. Like other components of TDEE, there are calculators for factoring your thermic effect of food into your total TDEE.

Once you know an idea of how many calories you are burning in a day, you can use TDEE as a guide to determine how many calories you should be eating. As a rule of thumb, those looking to lose weight should calculate a calorie intake that is 15-20 percent less than what is being burned — though you should never fall below your BMR. Keep in mind that TDEE is just an estimate, so it's important to listen to your body — if you need more, eat more! But even more important is to make those calories count as good fuel and consider nutrients over calories, says Dr. Goglia.

"Eighty calories from a hard-boiled egg will keep your body energized and nourished a little better than the 80 calories from a chocolate truffle. Try to consume real foods," says Becker. And keep in mind that your body uses more energy to burn protein and fats, which should help steer you away from a carb-dense meal plan.