Every nutrition panel you see on a product is going to present nutritional requirements based on a 2,000 calorie diet. But is that how many calories you really need to consume every day? Of course not, but 2,000 is a rough estimation of what the average person requires. That number can change drastically based on individual height, weight, gender, age and goals. A 5-foot-tall, 50-year-old woman who wants to lose weight is going to require a different amount of calories than a 6-foot-tall, 25-year-old man who wants to make serious gains.
To figure out how many calories you need to meet your goals, work out your basal metabolic rate and use that to determine your total daily energy expenditure. Confused? Don’t worry. There are tools to help with the calculations, and, once you work out that information, tailoring your calorie intake to your needs is easy. Read on and learn how to figure it out and what to do with the information.
Your basal metabolic rate (BMR) is the amount of energy, measured in calories, that your body uses to function at its absolute minimum at rest. This is the bare minimum for your cells to do their jobs when you’re not expending any additional energy outside of your vital functions – things like keeping your heart beating, your kidneys functioning and the body temperature stabilized. According to HowStuffWorks.com, this accounts for about 60 to 70 percent of the calories you burn throughout your day.
Your BMR his highly personal. Your weight, height, age, gender and body composition all factor into determining how much energy your cells use to keep functioning properly. So the amount of calories you need to survive might be drastically different than the amount your friends, family or gym buddies do. Generally, men have a higher basal metabolic rate than women do, though.
First things first: your BMR is not your BMI. You basal metabolic rate measures how many calories are required to fuel your body’s functions when completely at rest. Your body mass index measurement, or BMI, is an assessment of the relationship between your height and weight. BMI is an anthropometric tool, used to compare you against other humans, according to the United Nations University.
Knowing your basal metabolic rate and understanding its relationship to the function of your body is going to help you meet your health and fitness goals way more than knowing your BMI ever will. If you know how many calories your body requires to function at its bare minimum, you can apply that information to how your body is going to function with increased physical activity. You can learn how many calories you need to gain weight, to lose weight or to maintain.
There are three main factors that are used to calculate how many calories you require per day: your basal metabolic rate, your level of daily physical activity and the thermic effect of the foods you eat. Figuring out your BMR is the first step. You could use any number of free BMR calculators available online (like this one from BodyBuilding.com) or you could plug your numbers into these equations and figure it out on your own:
BMR = 10 x weight (in kilograms) + 6.25 x height (in centimeters) – 5 x your age (in years) + 5
BMR = 10 x weight (in kilograms) + 6.25 x height (in centimeters) – 5 x your age (in years) – 161
These are known as the Mifflin St. Jeor Equations and they’re generally regarded as more accurate than other BMR equations, such as the Harris-Benedict Equation.
Once you determine your BMR, you know how many calories you require to stay alive. Start with that information to calculate how many calories will meet your health and fitness goals. “You’ll want to use a BMR as a rough estimate of your basic needs,” Dr. Jennifer Sacheck, an associate professor of nutrition at Tufts University, told the Daily Burn.
Here’s where things get a little more complicated. You want to realistically estimate your total daily energy expenditure, or TDEE. This is how many calories your body needs when it’s not just laying there, existing. It must account for regular physical activity on top of all of your basic functional needs. The first of two components is the thermic effect of activity (TEA), which measures the amount of calories burned while you’re exercising. The second component is the thermic effect of feeding (TEF), which is the amount of calories your body uses to digest food and absorb nutrients.
The math behind your TDEE is a bit more complicated than determining your BMR, so look online for a calorie calculator from a respectable website, like the Daily Burn or BodyBuilding.com. Using your BMR, these calculators can help you find your TDEE. What you do with that information depends on your goals.
You finally know how many calories your body burns in a day, whether at rest or at work. Now what? You know by now that your calorie intake impacts your weight, so take the personalized information you have now and use to it modify your diet to meet your goals.
A caloric deficit is going to lead to weight loss. Cutting your calories by 10 percent or so will give you a slight deficit to help you shed weight safely. Conversely, a caloric surplus is going to help you gain weight. Eating more than your TDEE will create a surplus of calories that can be used to build muscle – as long as you’re putting in the time at the gym. And, naturally, eating exactly your TDEE is going to help you maintain your weight, so long as your level of activity remains the same.
Understanding your basal metabolic rate and your total daily energy expenditure can help you work out exactly how many calories to consume every day to help you meet your health and fitness goals. A deficit from your TDEE will help you lose weight, a surplus will help you gain and, just like Goldilocks, eating right in line with your TDEE will be just right for maintenance. Just remember that not all calories are created equal. Choose the ones that come with benefits like vitamins and minerals.