The first step in determining how many calories you need to consume each day isn't just how many minutes you spent on the stair-climber at the gym (though that does come into play), but rather what your metabolism is.
Okay, first of all, that word "metabolism" gets thrown around a lot, and many folks don't really know what it means or how to understand it as it relates to their lives. What is metabolism exactly?
Well, the scientific explanation goes something like this: Metabolism is a set of chemical reactions that take place in living things to maintain life. It consists of catabolism (the breaking down of matter to create energy) and anabolism (using energy to build or construct the components of cells). Blah, blah, blah... make sense?
Simply put though, metabolism is the rate at which your body burns calories.
Your BMR (basal metabolic rate) is the number of calories you need to fuel your body's basic energy needs at rest. Depending on how active you are you will need 20-90% more calories than your calculated BMR. Here's how to calculate your energy needs:
1. First, find your basal metabolic rate (BMR) by using this equation (or use the BMR calculator here):
o Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches ) - (4.7 x age in years)
o Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years)
2. To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:
o If you are sedentary (little or no exercise): BMR x 1.2
o If you are lightly active (light exercise/sports 1-3 days/week): BMR x 1.375
o If you are moderately active (moderate exercise/sports 3-5 days/week): BMR x 1.55
o If you are very active: BMR x 1.725
o If you are extra active (very hard exercise/sports and physical job or 2x training): BMR x 1.9
The number you get is the number of calories you need to eat in order to maintain your current weight. Decreasing that number by 500 calories per day is a good place to start if you want to lose about a pound per week.
If you want to do a quick estimate without a computer or calculator, a rule of thumb is that most people generally need a daily caloric range of somewhere between 7 and 10 calories per pound for long-term weight loss success, with a minimum of 1,200 calories per day.
Quick Tip: To make this complicated process easier, there are several reliable websites that have calorie need calculators. All you need to do is add in your age, gender, height and weight, and activity level. Online BMR calculators, such as the one from the Mayo Clinic, will do the math for you! WebMD also has a fun tool that will calculate your BMI and provide additional information.