Published: Mar 16, 2012 4:11 PM EDT
Updated: Mar 16, 2012 4:18 PM EDT

FORT MYERS, Fla.- Happy early St. Patrick's Day! Let's face it...everyone's a little Irish tomorrow and traditionally that means enjoying a green beer (or two).

If you plan to celebrate, why not rev up that metabolism and burn off those calories before the festivities. BUT what exactly is your “metabolism”? People can be the same height and weight, have the same BMI, and even fit into the same pair of jeans, but have very different muscle-to-fat proportions, making one person thecalorie-burning equivalent of a Bic lighter and the other of a blowtorch.

Wink News Fitness Expert Mike Drumm is here today to explain the basics of your metabolism, the different factors that affect it, and an easy way to calculate your metabolic rate.

Drumm: If I had a dollar of every time I heard that “Metabolism” was to blame for weight gain I would be rich. However, there is truth in the statement… understanding what your Metabolic Rate is will give most people an eye opener as to how what you eat and how often you exercise control your caloric balance. So you control your Metabolism, it does not control you.

Metabolism is the body’s way of converting food into energy, and thenusing that energy to sustain and build the body. It takes a complex and interrelated series of chemical and physical processes to accomplish that. 65 percent of those calories are used up for 24-7 functions like breathing and circulation¬ -- the top burners are your brain, liver, heart, and kidneys -- with another 10% devoted to the process of digesting the very foods that may have given you that muffin top in the first place. The remaining 25 percent of the calories you burn can be chalked up to the physical activity you do in a day -- not just spinning class but every move you make!

Your Basal Metabolic Rate (BMR)

Understanding your Basal Metabolic Rate (BMR) is a way to estimate your daily calorie needs based on your gender, height, weight, age, and activity level. However, frame size, medications, health conditions, body fat percentage, and other factors can change your calorie needs significantly. If you have questions about your overall calorie requirements, check with your health care provider.


You've heard it before: The more muscle you have, the more calories you burn. In fact, lean tissues, including organs and muscles, on average burn 14 calories a pound a day, while fat only burns about three calories per pound. It’s the amount of muscle in you that determines the overall speed of your resting metabolism -- the amount you burn just sitting around -- and some of us are born with an edge in the amount of muscle fibers we've got. But don't blame bad genes for your extra flab.

Like a Your Car Engine: A simple way to understand your body’s metabolism? It works a lot
like the engine of a car.

To get up and go, your body needs food, much like a car engine needs fuel. Your body’s engine is your metabolism. When you rev the engine—say, when exercising—you burn more fuel. And when your engine is a finely tuned metabolism, your body burns its fuel most effectively, and with less waste. That means less fat and greater fitness for you.

Fueling your system is a calories in/calories out proposition. The “calories in” come from food fuels: fats, carbohydrates, proteins. The body uses each of those fuel sources for different purposes, and excess calories are stored in a way that is unique to each fuel source. (Take fat, for instance: The body has seemingly unlimited capacity to store excess fats, and it does so in a decidedly bulky way.

The “calories out” are burned off through physical activity such as exercise, the digestion of food, and resting metabolism. The amount of calories burned via physical activity is largely up to you: your activity levels and your workout routine. The energy it takes to use the food you eat requires a nominal 10% of the total calories out. Your resting metabolism—meaning the amount of energy required to do all the things a body does to stay up and running, from the breathing you hardly even notice to the thinking you’re doing at this very moment—commands most of the calories out, at 60 percent to 70 percent.

What Affects Your Metabolism: It's your environment -- that is, food and activity -- that ultimately determine your weight. And there's plenty you can do to not only add muscle but also maximize your metabolism along the way. A person's metabolism varies with their physical condition and activity. Weight training can have a longer impact on metabolism than aerobic training,


How to Calculate your Basil Metabolic Rate:  The BMR formula uses the variables of height, weight, age and gender
to calculate the Basal Metabolic Rate (BMR). Remember, leaner bodies need more calories than less leaner ones. Therefore, this equation will be very accurate in all but the very muscular (will underestimate calorie needs) and the very fat (will over-estimate calorie needs).

Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )

Harris Benedict Formula: The Harris Benedict Equation is a formula that uses your BMR and then applies an activity factor to determine your total daily energy expenditure (calories). To determine your total daily calorie needs, multiply your BMR by the appropriate activity factor, as follows:
1.      If you are sedentary (little or no exercise) : BMR x 1.2
2.      If you are lightly active (light exercise/sports 1-3 days/week) : BMR x 1.375
3.      If you are moderatetely active (moderate exercise/sports 3-5 days/week) : BMR x 1.55
4.      If you are very active (hard exercise/sports 6-7 days a week) : BMR x 1.725
5.      If you are extra active (very hard exercise/sports & physical job or 2x training) : BMR x 1.9

Total Calorie Needs Example: If you are sedentary, multiply your BMR (1745) by 1.2 = 2094. This is the total number of calories you need in order to maintain your current weight.

Once you know the number of calories needed to maintain your weight, you can easily calculate the number of calories you need to eat in order to gain or lose weight.