Calories are not evil. They have no ulterior motives and are not out to get anyone. A calorie, named for the Latin calor meaning "heat," is a unit of heat energy discovered by Nicolas Clement in 1824. One dietary calorie (because there are different types) is the energy needed to raise the heat of one kilogram of water by one degree centigrade. In more scientific circles, the common food calorie is referred to as a "kilocalorie" and represented by a capital letter "C."
The body is always burning calories. "Burning" in this case is the metabolic process of enzymes breaking the food apart. Even reading this article is causing the body to expend a small amount of extra energy, using more calories. Reading this while using a treadmill exponentially increases that number. There are three ways that the body burns calories.
Between 60 and 70 percent of one's daily calorie expenditures goes toward its BMR. The basal metabolic rate (BMR) is the body's baseline, what it needs to perform its most basic functions at rest: breathing, heart beats, body temperature, pumping blood, etc. The number of calories needed for the BRM is different for each person, but higher in men.
Broccoli would probably not be one’s first choice over chocolate cake, but it has much more to offer the body in the way of nutrients.
Physical activity burns calories, which is the whole premise behind aerobics, gyms and mall walking. One pound of fat is the equivalent of 3500 calories. While the body takes in more food each day, the fat sits, waiting to be used. Like it or not, the only way to rid the body of excess fat is to get the body to work hard enough to need more energy and tap into the stored energy.
The third way the body burns calories is the thermic effect, or eating and processing food. Food fats contain the most energy, nine calories per gram, but they are also the easiest substances to process, therefore the body expends the least amount of energy. Proteins contain four calories of energy per gram, but are more complicated to process, increasing the thermic effect. Carbohydrates also contain around four calories per gram, but are not as difficult for the body to process.
So if a calorie is simply a unit of heat, it doesn't matter whether it comes from chocolate cake or broccoli, right? Alas, no. Amanda Hartley, RD/LD at Eastern Ohio Regional Hospital, explains, "Not all calories are created equal. Eating 50 calories worth of vegetables is going to give you an added bonus of vitamins and minerals versus eating 50 calories worth of cake, which offers little to no benefits[Also,] foods like cake are easily digested and require little energy to be broken down into a form the body can use as energy. This differs from a food like broccoli, which requires more energy to be used during digestion, ultimately leading to more calories being burned."
Each person's metabolism is unique, but there are some points that are the same for everyone. First, in extreme environments (hot or cold) the BMR can increase by five to 20 percent as the body tries to cool or warm itself. Changes in internal body temperature can also raise the metabolic rate.
In regard to physical activity, cardio work like aerobics, walking, dancing and the elliptical machine can raise your metabolism for up to two hours after finishing the activity. Weight training can have a longer impact on the rate, and building and toning muscles will raise the BMR because muscle tissue takes more energy to maintain than stored fat.
Other things that affect metabolism include stress and illnesses like diabetes, both of which can raise the rate. Medications can affect the BMR, too. For instance, antidepressants may lower it.
Anyone can calculate his or her BMR, the calories necessary to fuel the normal processes at rest. For adult men this formula is 66 + (6.3 x body weight in pounds) + (12.9 x height in inches) (6.8 x age.) For adult women the formula is 655 + (4.3 x body weight in pounds) + (4.7 x height in inches) (4.7 x age.) Once you know your BMR, try adding up calories eaten over two or three days. This will give you an idea of how much your body is eating as opposed to using, and you can make better decisions on whether to change calorie intake or add an extra walk each week.
An online calorie counter like www.caloriecounter.about.com shows users differences even among the same types of foods, which may be surprising. To illustrate, one serving of Tombstone Original Pepperoni Pizza contains 312 calories of which 28.2 grams are carbs, 14.5 are protein and 15.7 are fat (6 of those are saturated fat.) Choosing a large slice of Domino's Classic Hand Tossed Pepperoni Pizza will save you almost 100 calories (at 218), over 11 grams of fat (4.1) and 4.5 grams of saturated fat (1.4). The Domino's slice has eight more grams of carbs (36.2), but still has 8.2 grams of protein.
Restaurant menus are beginning to include calorie counts. Nutrition information can also be found on restaurant websites and sites like CalorieCounter. A recent study of chain restaurants outside of Boston, Mass., Little Rock, Ark., and Lafayette, Ind., determined that items like sandwiches and burgers are fairly close to accurate counts, but that menu items like dressed salads, side dishes and high-carb foods consistently understated the calories. About 19 percent of the items actually had more than 100 calories above the count on the menu. The researchers' recommendation was to eat half of the entree when dining out.
When revamping your diet, think "fresh is best." Fresh fruits and vegetables have natural nutrients that are better for the body and untainted by chemicals and preservatives used during processing. Hartley suggests that out of season, or if watching the food budget, choose canned vegetables with lower sodium content and fruits canned in real juice rather than syrup.
Another online tool can help calculate the calories used during given activities. A "calories burned" calculator at www.healthstatus.com will tally up a day's worth of them after you punch in your weight and time spent on various activities. A 190 pound man will use up 410 calories an hour farming and feeding livestock or 182 calories an hour driving. A 125 pound woman can use 345 calories swimming for an hour and 308 for every hour of gardening.
Hartley says, "It is important to make both diet and behavioral changes. When we make these lifestyle changes, we are more apt to lose weight and keep it off, versus jumping from one fad diet to the next."
Befriend the calorie, life's fuel. Becoming familiar with how your body works and what it needs will enable you to make adjustments that will be healthier and easier to maintain over the long term. If the goal is weight control, monitoring not only the number but the type of calories could make a difference, not only taking extra pounds off, but keeping them off.