Energy requirements are based on multiple factors including training frequency, type, intensity, body composition, size, and goals. The formulas and recommendations are not set in stone. It is important to use a multitude of tools to determine if you're achieving proper energy balance such as appetite, weight, mood, body fat percentage, and overall health.
The human body uses about 60% of calories just to keep up with natural processes at rest. The amount of calories you burn at rest is termed your basal metabolic rate (BMR). The more lean muscle mass you have the higher your BMR. By building a leaner more muscular physique you increase your calorie burning abilities around the clock!
The remainder of the energy pie is divided between activity and digestion. 30% of energy (calories) is used for physical activity while 10% is used in the process of digestion. This is why you can burn more calories by eating smaller meals more often.
To determine your basal metabolic rate (BMR), aka how many calories your body burns at rest, use the following formula:
Formula For BMR:
W = weight in kilograms (weight (lbs)/2.2) =weight in kg
H = height in centimeters (inches x 2.54) =height in cm
A = age in years
Men: BMR=66.47+ (13.75 x W) + (5.0 x H) - (6.75 x A)
Women: BMR=665.09 + (9.56 x W) + (1.84 x H) - (4.67 x A)
Use the Rule of Ten (or Eleven):
BMR= 10 calories/pound of bodyweight for women
BMR= 11 calories/pound of bodyweight for men
Example: If you weigh 200 lbs your BMR is 2, 200 calories.
Note: The above equations do not account for individual body composition.
This equation is based on your body composition. You need 13.8 calories to support 1 pound of lean muscle mass.
BMR= Lean body mass (lbs) x 13.8 calories
You can obtain your lean body mass from body fat measurements.
Calculate lean muscle mass vs. fat mass:
Body fat % x scale weight= fat mass
Scale weight - fat mass= lean body mass
Once you calculate your BMR factor in activity to account for calories burned during exercise.
BMR x 1.2 for low intensity activities and leisure activities (primarily sedentary)
BMR x 1.375 for light exercise (leisurely walking for 30-50 minutes 3-4 days/week, golfing, house chores)