The official definition of a calorie is "...the amount of heat needed to raise the temperature of a liter of water 1 degree (DHHS)." But if that's a little too scientific for you, think of it this way...

A calorie isn't actually a tangible thing, it's a unit of measurement.

A calorie measures the energy in food and beverages we take in. We all need that energy to live. Everything we do relies on the energy that comes in the form of calories.

The food we eat becomes the fuel that runs our bodies. Drinks also contain calories, but sodas for example are referred to as "empty calories" meaning they carry no other nutritional value; but the calories definitely still count.

The History of Food Labels

Food labels were regulated in 1994. Before then, food companies could print their products¡¯ nutritional information basically anywhere they wanted to (and often in really small print).

The Food and Drug Administration required companies to format the information in a structured way and to include helpful information on the label -- in a set size and organized manner.

These regulations required both the ingredients and nutritional information to be provided along with a food label of a standard size and shape (a rectangle) labeled ¡°Nutrition Facts¡±. In this box, you will find nutritional information listed in order of importance.

In 1994, the FDA and U.S. Department of Agriculture required that:

Physical activity has made its way into the new food pyramid. But it's not just about going to the gym. You can be active in many different ways.

Walking, gardening, briskly pushing a baby stroller, climbing the stairs, playing soccer, or dancing the night away are all good examples of being active. For health benefits, physical activity should be moderate or vigorous and add up to at least 30 minutes a day.

What Is Moderate and Vigorous Activity?

Moderate physical activities include:

• Walking briskly (about 3 1/2 miles per hour)
• Hiking
• Gardening/yard work
• Dancing
• Golf (walking and carrying clubs)
• Bicycling (less than 10 miles per hour)
• Weight training (general light workout)