Losing or gaining body weight is a matter of getting the right balance between energy in and energy out. The 'energy in' component is determined by the food you eat. The 'energy out' component is determined by the energy expenditure of the cells of your body. There are two primary components that make up your body's energy expenditure, the energy you use at rest (basal metabolic rate, BMR) and the additional energy that is expended during physical activity (METs).
See the specific pages on BMR and METs to understand and determine your daily energy requirements. On top of your resting energy expenditure, you need to adjust for the amount of activity performed. There are many ways to estimate your total daily energy expenditure. If you are after just a simple rough estimate, there are some example formula below. Be aware that the range for calculated total daily energy expenditure is highly variable. It depends on many factors, including: activity level, age, gender, size, weight and body composition. Using a pedometer is another simple way of estimating daily energy expenditure.
A Simple Formula
You can roughly estimate your daily calorie requirements using the following simple formulas:
- For sedentary people: Weight in lbs x 14 = estimated cal/day
- For moderately active people: Weight in lbs x 17 = estimated cal/day
- For active people: Weight in lbs x 20 = estimated cal/day
The Harris-Benedict Principle
Use the following table to calculate your recommended daily calorie intake to maintain current weight. To estimate your total energy expenditure, you first need to know your Basal Metabolic Rate (BMR).
|Calorie Calculation (Daily Needs)
|Little to no exercise
|BMR x 1.2
|1-3 days per week
|BMR x 1.375
|3-5 days per week
|BMR x 1.55
|6-7 days per week
|BMR x 1.725
|Very heavy exercise
|twice per day, extra heavy workouts
|BMR x 1.9
- About Energy Expenditure — methods, formula and calculators.
- Energy Expenditure using a Pedometer — by counting steps you can estimate how much energy you are using.
- Daily Calorie Counter — determines how many calories you need each day.
- Power output and energy expenditure for running and walking
- Calories Burned Running — determines how many calories you have burned based on your weight and distance run.
- Direct measurement of BMR and RMR
- Nutrition calculators
- Walking for weight loss — an argument for why you shouldn't do it
- Lose weight while doing nothing — making use of BMR for weight loss.