## What's TDEE

#### TDEE is short for total daily energy expenditure. It's the number of calories you burn daily based on your lifestyle.

Total daily energy expenditure is comprised of three components: basal metabolic rate, activity level and thermogenic effect of food.

Your basal metabolic rate (BMR) is the number of calories you need to stay alive. These calories are used to provide energy for functions such as breathing, circulating your blood, digesting your food, etc. In addition to staying alive your body needs to burn calories to support your daily activites. For example, a software engineer like myself burns less calories than professional football player (age, weight, height being equal). Your BMR calories are multiplied by your personal activity level to calculate your TDEE.

The thermogenic effect of food (TEF) accounts for about 10% of your TDEE. This refers to the number of calories your body burns digesting the foods you consume. Your body requires more energy to digest protein in comparison to the other macronutrients so all things being equal, a diet higher in protein will result in burning more calories than a diet higher in fat. This is one of the reasons you'll hear that eating more protein keeps you feeling fuller longer.

## TDEE Formulas

#### Harris-Benedict (Original)

This equation was published in 1919 and is probably the oldest formula used to calculate a person's basal metabolic rate. The equation calculates BMR differently for men and women by using different multipliers.

Women
(9.5634 * weight in kg) + (1.8496 * heigh in cm) - (4.6756 * age in years) + 655.096

Men
(13.7516 * weight in kg) + (5.0033 * heigh in cm) - (6.755 * age in years) + 66.473

#### Harris-Benedict (Revised)

The Harris-Benedict equation was revised in 1984 by Roza and Shizgal.

Women
(9.247 * weight in kg) + (3.098 * height in cm) - (4.330 * age in years) + 447.593

Men
(13.397 * weight in kg) + (4.799 * height in cm) - (5.677 * age in years) + 88.362

#### Katch-McArdle (Original)

This equation takes your body composition into account by taking your bodyfat and lean body mass into account. It's considered the more accurate formula for athletes with lower bodyfat levels. It's the same calculation for men and women because lean body mass is an indicator of gender and age.

370 + (21.6 * (weight in kg * (1 - bodyfat percentage)))

#### Katch-McArdle (Hybrid)

This equation is a variation which on the Katch-McArdle intended to be accurate for athletes with lower bodyfat levels as well as normal individuals with higher bodyfat levels.

(370 * (1 - bodyfat percentage )) + (21.6 * (weight in kg * (1 - bodyfat percentage))) + (6.17 * (weight in kg * bodyfat percentage))

#### Mifflin-St Jeor

This is one of the newer and more accurate equations for normal individuals. It doesn't take body composition into account and may not be as accurate for athletes.

Women
(10 * weight in kq) + (6.25 * height in cm) - (5 * age in years) - 161

Men
(10 * weight in kg) + (6.25 * height in cm) - (5 * age in years) + 5

#### Cunningham

This equation is basically the same as the Katch-McArdle. It calculates resting metabolic rate (RMR) rather than basal metabolic rate (BMR) so the results tend to be higher. It's a very minor difference so we use it in our calculations.

500 + (22 * (weight in kg * (1 - bodyfat percentage)))