Whether you are sitting on the sofa watching TV or going ‘Beast Mode’ in the gym, your body needs energy to function. The energy we need comes from the food we eat and each food consists of nutrients; carbohydrates, protein and fat.
The word “calorie” is used to describe the amount of energy in food and the amount of energy stored in the body as body fat and glycogen (stored carbohydrate). Fats contain 9 calories per gram, and carbohydrates and proteins contain 4 calories per gram.
Body fat is like a reserve storage tank for energy. When we speak of “burning off fat” we are talking about releasing calories from your “storage tank” and burning them to fuel your activities.
If you’re a 180-pound man with about 20% body fat, you have 36 pounds of body fat.
There are 3500 calories in each pound of body fat, which adds up to a grand total of 126,000 calories of reserve energy in storage! Click here to have a look at how many calories these activities burn in 30 minutes.
By understanding calories and balancing your input with your output, you can easily lose fat or maintain a healthy and attractive body fat ratio.
To lose weight, you must burn more calories than you consume each day.
To gain weight, you must consume more calories than you burn each day.
How do I determine how many calories I should eat per day?
The first step in designing your personal fat loss plan is to calculate the total number of calories you burn up every day. This is known as your total daily energy expenditure (TDEE). TDEE is also known as your “maintenance level,” because this is the level where the amount of calories you put in your body are exactly equal to the amount of calories you burn.
TDEE is the total number of calories your body burns in 24 hours, including BMR and all activities. Once you know your maintenance level, you will have a reference point from which to start your program.
Your daily calorie needs are influenced by 6 factors: BMR, Activity level, Weight, Lean Body Mass, Age and Gender.
The Harris-Benedict formula
The Harris-Benedict formula uses the factors of height, weight, age, and gender to determine basal metabolic rate (BMR).
Men: BMR = 66 + (13.7 X wt in kg) + (5 X ht in cm) – (6.8 X age in years)
Women: BMR = 655 + (9.6 X wt in kg) + (1.8 X ht in cm) – (4.7 X age in years)
2.54 centimeters = 1 Inch
1 kilogram = 2.2 pounds
You are female
You are 28 yrs old
You are 170 cm’s tall
You weigh 58 kilos
Your BMR = 655 + 556.8 + 306 – 131.6 = 1386 calories/day
Once you know your BMR, you can calculate TDEE by multiplying your BMR by the
following activity factor.
Sedentary = BMR X 1.2 (little or no exercise, desk job)
Lightly active = BMR X 1.375 (light exercise/sports 1-3 days/wk)
Mod. active = BMR X 1.55 (moderate exercise/sports 3-5 days/wk)
Very active = BMR X 1.725 (hard exercise/sports 6-7 days/wk)
Extr. Active = BMR X 1.9 (hard daily exercise/sports & physical job or
2 X day training)
Continuing with the previous example:
Your BMR is 1386 calories per day
Your activity level is moderately active (work out 3-4 times per week)
Your activity factor is 1.55
Your TDEE = 1.55 X 1386 = 2148 calories/day
Adjust your caloric intake according to your goal
Once you know your TDEE (maintenance level), the next step is to adjust your calories according to your primary goal. The maths of weight control are simple:
1) To keep your weight at its current level, you should remain at your daily caloric maintenance level.
2) To lose weight, create a 500-1000 calorie deficit by reducing your calories below your maintenance level (or keeping your calories the same and increasing your activity above your current level).
3) To gain lean body weight, increase your calories 500-1000 above your maintenance level (and engage in a program of progressive strength training).