Our bodies constantly burn energy, and understanding how much we burn is essential for achieving our health and fitness goals. Two key measurements, Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE), show us our personal energy balance (BMR vs TDEE).
Imagine your body as a car.
BMR is like the fuel your car burns while idling at a stoplight – the energy you need just to keep your basic bodily functions running.
TDEE, on the other hand, is like the total fuel your car uses during a day’s worth of driving – it includes your BMR plus all the energy you expend moving around and exercising.
What is BMR (Basal Metabolic Rate)?
Imagine your body as a bustling city that never sleeps. Even when you’re lounging on the couch or chilling in bed, your body is hard at work. Your heart’s pumping, your lungs are breathing, your brain’s thinking, and your cells are busy repairing and regenerating. All this activity requires energy, and that’s where your Basal Metabolic Rate (BMR) comes in.
BMR is essentially your body’s energy bill for just existing. It’s the number of calories you’d burn if you stayed in bed all day, not moving a muscle. Think of BMR as your body’s ‘idle mode’ – the bare minimum energy needed to keep your vital organs functioning.
But here’s the kicker: your BMR isn’t set in stone. It’s as unique as your fingerprint, and it’s influenced by several factors:
- Age: As we get older, our BMR typically decreases. It’s like our body’s engine becomes more fuel-efficient (or stubborn, depending on how you look at it).
- Gender: Generally, men have a higher BMR than women, even at the same height and weight. Blame it on testosterone and higher muscle mass.
- Height and Weight: Larger bodies generally require more energy to maintain. It’s like heating a mansion versus a studio apartment.
- Body Composition: Muscle tissue burns more calories than fat tissue, even at rest. So, the more muscular you are, the higher your BMR.
Now, you might be wondering, “How do I find out my BMR?” Well, unless you fancy spending a day in a high-tech lab, you probably won’t get an exact measurement. The gold standard for measuring BMR is through indirect calorimetry, which involves analyzing your breath in a controlled setting. But don’t worry, there are simpler ways.
Most of us rely on equations that estimate BMR based on age, gender, height, and weight. Popular formulas include the Harris-Benedict equation and the Mifflin-St Jeor equation. While not perfect, these can give you a pretty good ballpark figure.
So, what’s a typical BMR? Well, it varies widely, but here are some rough averages:
- Adult women: 1,200 to 1,600 calories per day
- Adult men: 1,400 to 1,800 calories per day
Remember, these are just averages. Your personal BMR could be higher or lower depending on your unique characteristics. The easiest way to figure out your personal BMR is to use a wearable, like an Apple Watch or Fitbit, and use the Zolt app.
Understanding your BMR is like knowing your car’s fuel efficiency. It’s the starting point for figuring out how much energy your body needs daily.
But BMR is just part of the story – next, we’ll look at how your daily activities bump up your calorie burn.
What is TDEE (Total Daily Energy Expenditure)?
Remember how we said BMR is like your body idling? Well, TDEE is your body’s total mileage for the day. It’s the whole enchilada of calorie burning – everything from keeping your heart beating to running that 5K you’ve been training for.
TDEE stands for Total Daily Energy Expenditure, and it’s exactly what it sounds like: the total amount of energy you burn in a day. Think of it as your body’s daily trip to the gas station. It’s all the fuel you use, not just for basic functions, but for every single activity you do, from walking to work to bench pressing.
Now, let’s break down this calorie-burning fiesta into its main components:
- BMR (Basal Metabolic Rate): This is our old friend from the last section. It’s the lead singer of the band, typically accounting for 60-70% of your TDEE. Even when you’re doing nothing, your BMR is working hard.
- TEF (Thermic Effect of Food): Ever felt warm after a big meal? That’s TEF in action. It’s the energy your body uses to digest, absorb, and process the food you eat. Think of TEF as the drummer, providing a steady beat that keeps things moving. It usually accounts for about 10% of your TDEE.
- NEAT (Non-Exercise Activity Thermogenesis): This is a fancy term for all the calories you burn through non-exercise movement – things like fidgeting, walking to your car, or dancing while you cook. NEAT is like the guitarist of the band, adding flair and variation to your daily energy expenditure. It can vary greatly from person to person and day to day.
- EAT (Exercise Activity Thermogenesis): Finally, we have EAT – the calories you burn during intentional exercise. Whether you’re lifting weights, running, or doing yoga, this is where that energy goes.
A TDEE breakdown generally looks like this, which is from Metabolic adaptation to weight loss: Implications for the athlete.
Now, what influences your TDEE? Well, quite a few things:
- Physical activity: The more you move, the higher your TDEE. A marathoner will have a much higher TDEE than a couch potato, even if they have the same BMR.
- Body composition: Remember how muscle burns more calories than fat? That applies here too. The more muscle mass you have, the higher your TDEE.
- Diet: What you eat can influence your TEF. Protein generally has a higher thermic effect than fats or carbs.
- Age: As we get older, our TDEE tends to decrease, partly due to losing muscle mass and becoming less active.
- Climate: Believe it or not, living in very hot or very cold environments can increase your TDEE as your body works to maintain its temperature.
- Hormones: Conditions that affect your hormones, like thyroid issues, can significantly impact your TDEE.
Understanding your TDEE is like having a personalized energy budget. It tells you how many calories you’re burning each day, which is crucial information whether you’re trying to lose weight, gain muscle, or maintain your current physique.
Calculating BMR and TDEE
BMR and TDEE can be roughly calculated using some equations – and are best calculated by using a combination of a wearable + the Zolt app. Let’s dive into the details.
Common formulas for estimating BMR
First up, let’s talk BMR. While the most accurate way to measure BMR involves lying in a lab hooked up to a bunch of machines (sounds fun, right?), there are some tried-and-true formulas we can use to get a pretty good estimate.
The two most popular formulas are the Harris-Benedict equation and the Mifflin-St Jeor equation. Here’s a quick rundown:
- Harris-Benedict Equation:
- For men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) – (5.677 × age in years)
- For women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) – (4.330 × age in years)
- Mifflin-St Jeor Equation:
- For men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- For women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
The Mifflin-St Jeor equation is generally considered more accurate for most people, but both can give you a good starting point.
How to estimate TDEE using BMR and activity levels
Now that we’ve got our BMR, it’s time to level up to TDEE. The simplest way to estimate TDEE is to multiply your BMR by an activity factor. It’s like BMR is the base model of a car, and your activity level is all the fancy add-ons.
Here’s a quick guide to activity factors:
- Sedentary (little to no exercise): BMR × 1.2
- Lightly active (light exercise 1-3 days/week): BMR × 1.375
- Moderately active (moderate exercise 3-5 days/week): BMR × 1.55
- Very active (hard exercise 6-7 days/week): BMR × 1.725
- Extra active (very hard exercise & physical job): BMR × 1.9
So, if your BMR is 1500 calories and you’re moderately active, your estimated TDEE would be 1500 × 1.55 = 2325 calories.
Online calculators and apps for BMR and TDEE
Now, if all this math is making your head spin, don’t worry! We live in the age of technology, and there are plenty of online calculators and smartphone apps that can do all this number-crunching for you.
We have:
- Zolt: Not only calculates your BMR and TDEE, but has it change and adapt to your body over time as it learns about your body, metabolism, habits, and lifestyle. It’s like a personalized coach.
- TDEE Calculator: A straightforward, no-frills calculator that gives you both BMR and TDEE.
- BMR Calculator: Offers both Harris-Benedict and Mifflin-St Jeor calculations.
Remember, though, these calculators and formulas are just estimates. They’re a great starting point, but everyone’s body is unique. You might need to adjust your calories up or down based on how your body responds.
Also, keep in mind that your TDEE can change. If you start exercising more, your TDEE will increase. If you lose weight, both your BMR and TDEE will likely decrease.
That’s why Zolt makes it easy by calibrating, calculating, and coaching you through your BMR and TDEE changes everyday.
The Best Way to Track your TDEE and BMR
Calculators can only take you so far. Everybody is different and as a result, calculators will always be slightly off in their calculations for your own body.
That’s where Zolt comes in. Zolt helps you find your BMR and TDEE to help you lose fat, gain muscle, or maintain your weight.
To do so, Zolt uses a proprietary algorithm that takes into account your bodyweight trends, calorie intake trends, actual activity, and wearable metrics to calculate the most accurate TDEE personalized for your body, metabolism, and lifestyle.
Zolt is free to use!