Back to Basics: Calories Explained

FitSugar — Wed, 03 Dec 2008 03:00:00 -0800

We talk, or at least think, about calories almost daily. You cut calories. You count them. You burn them. But do you know what a calorie is?

Simply put, a calorie is a unit of energy. When you eat, you're fueling your body with potential energy in the form of calories, which your body uses not just for exercise but for vital functions like breathing. Basically, a calorie is the amount of energy it takes for the temperature of one gram of water to increase by one degree Celsius, or 1.8 degrees Fahrenheit. However, when we talk about calories burned or calories consumed we are technically talking about kilocalories, each of which equals 1,000 calories. Kilocalories are most often referred to as calories for short. Scientifically speaking, the term is capitalized, but in most literature about food and exercise "calorie" is written in all lowercase and it's assumed we are all talking about the same unit of measurement.

Foods are made out of mixtures of macronutrients: protein, carbs, and fat. Protein and carbs each contain four calories per gram, while fat contains nine calories per gram. These caloric amounts represent the amount of potential energy these macronutrients provide.

To see how the body burns calories, just read more.

The body uses calories for three distinct categories of activities. One is your basal metabolic rate (BMR), or how many calories your body burns just to keep the basic operations going - heart beating, kidneys functioning, lungs breathing. Sixty to 70 percent of all calories go toward just keeping your body operational, kind of like overhead expenses. The body also needs calories for physical activity, be it washing your dishes, walking your dog, or running a marathon. The third component of calories burned is the thermic effect of food, or how much energy it takes to digest your food to turn it into energy. Your body burns 10 percent of overall calories consumed to fuel the digestion process of those calories you just consumed.

Food is energy, or calories, that you put into your body to fuel all your activities for the day. If you do not use all that fuel, your body stores the fuel just in case you need it during a famine, and you gain weight. If you use more fuel than you have consumed, by burning more calories than you have eaten, you will lose weight.

The Health Guide has some pretty cool tools to help you understand your personal relationship with calories. To see how many calories your body requires to maintain your weight, check out this Nutritional Needs Calculator. To see roughly how many calories you're burning during a variety of activities, visit the Calorie Burner Calculator.

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Make the Most of Your Metabolism

FitSugar — Tue, 19 Jun 2007 02:00:00 -0700

Most of what controls your metabolism is not under your control, some folks have fast metabolisms and others have slow ones. Also, as we age our metabolism slows down. Scientists have estimated that metabolism slows about 5 percent per decade, beginning at age 40 as we lose muscle mass and increase body fat. Muscle burns more calories than fat, so when you lose muscle mass your caloric needs decrease. Luckily you are not completely at the mercy of your genetics - There are a few things you can do to keep your metabolism up.

Basically, metabolism is the total of all body processes that burn calories - your basal metabolic rate (calories burned by simply being alive) plus your activity factor since we all know that exercise burns calories.

The basal metabolic rate includes the energy we need for body processes, including digestion. About 10 percent of our calories are used to process the food we eat. This phenomenon, known as the thermic effect of food, is influenced by how much, how often and what we eat. In addition, food can directly affect metabolism by altering the way the body functions, which changes the amount of energy it needs.

According to Joy Bauer, nutritionist and author of the book Food Cures, there are ways to maximize your metabolism. Curious to know what they are? Then read more

Eat at least 1,000 calories per day (I would say 1,200 calories, myself). Although it is generally true that eating a low-calorie diet will help you take off weight, if you eat too few calories, your metabolism will get slower and slower as it tries to conserve energy. As your metabolism crashes, the weight you take off will most likely creep back on over time. Plus, you'll be more likely to binge on junk food if you reduce your calories by too much.
Eat every four to five hours. A regular meal schedule helps keep your body working to digest and absorb foods. Between breakfast and bed, aim to eat a meal or snack every four to five hours. Try to eat breakfast within 90 minutes of rising - People who regularly eat a healthy breakfast are more likely to control their weight. If you wait to eat until you're ravenous, you're more likely to overeat later in the day. Also, breakfast helps fire up your metabolism after a full night on a slow simmer.
Eat protein with every meal. All foods contribute to the thermic effect, which means that all foods – carbohydrates, fats and proteins – help to give metabolism a gentle nudge higher when we eat them, but protein has the greatest thermic effect of all. In addition, protein can increase metabolism by helping to maintain and build muscle mass.

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