TDEE Explained
Your Total Daily Energy Expenditure is the single most important number for any body composition goal. Here's what it means, how it's estimated, and how to actually use it.
What is TDEE?
TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a single day. It includes everything: keeping your organs alive, digesting food, walking to the kitchen, and your gym session.
In simple terms: it's your BMR (the calories you'd burn lying in bed all day) plus all the energy you spend on activity. If you eat more than your TDEE, you gain weight. Eat less, you lose weight. Eat at it, you maintain. Every diet and nutrition strategy is ultimately working with this equation.
The Four Components of TDEE
BMR
~60-70%Basal Metabolic Rate
The calories your body burns at complete rest — just to keep your organs running, your heart beating, and your cells alive. This is the largest chunk of your daily burn by far.
NEAT
~15-30%Non-Exercise Activity Thermogenesis
Everything you do that isn't planned exercise: walking, fidgeting, standing, cooking, cleaning. This varies enormously between people and is the main reason some people seem to "burn more calories" than others.
TEF
~8-15%Thermic Effect of Food
The energy your body uses to digest, absorb, and process food. Protein has the highest thermic effect (~20-30%), followed by carbs (~5-10%), then fat (~0-3%).
EAT
~5-10%Exercise Activity Thermogenesis
Planned exercise — gym sessions, runs, sports. This is the smallest component, which surprises most people. Even a hard hour-long workout is a small fraction of your total daily burn.
How TDEE Is Estimated
TDEE calculators use formulas like Mifflin-St Jeor or Harris-Benedict to estimate your BMR from your age, height, weight, and sex — then multiply by an activity factor to account for daily movement and exercise.
The activity multiplier is the weakest link. Most people overestimate their activity level. Selecting "moderately active" when you sit at a desk 8 hours a day and hit the gym 3 times a week will overestimate your TDEE. When in doubt, choose one level lower than you think.
A calculator gives you a starting point — not a precise number. Your real TDEE is found by tracking your calorie intake and weight change over 2-4 weeks. If your weight stays stable, you've found your maintenance. If it's moving, adjust by 100-200 calories and reassess.
Using Your TDEE
Fat Loss
300-500 below TDEE
A moderate deficit is the sweet spot. Larger deficits aren't faster long-term — they increase muscle loss, tank your energy, spike hunger hormones, and raise the risk of binge-restrict cycles. Slow and steady genuinely wins here.
Maintenance
At TDEE
Eating at maintenance is useful for diet breaks between cutting phases, body recomposition (losing fat and gaining muscle simultaneously), or simply learning to sustain your current weight. It's also the most sustainable long-term approach.
Muscle Gain
200-300 above TDEE
A small surplus paired with strength training maximises muscle growth. Larger surpluses don't build muscle faster — your body has a limited rate of muscle growth. The extra calories just get stored as fat.
Common Misconceptions
"I have a slow metabolism"
BMR varies only about 200-300 calories between similarly-sized people. The real variable is NEAT — some people unconsciously move much more than others, burning hundreds of extra calories daily without realising it.
"Exercise burns tons of calories"
A hard 1-hour session might burn 300-500 calories. That's a single muffin or a couple of tablespoons of peanut butter. Easy to eat back in 5 minutes. Exercise is essential for health and muscle, but it's a poor primary weight loss tool.
"Eating less always means losing more"
Adaptive thermogenesis is real: when you undereat aggressively, your body reduces NEAT (you move less without realising), lowers BMR slightly, and increases hunger hormones. A moderate deficit avoids triggering these adaptations as strongly.