What's on a "Nutrition Fact" food label?

Most food products currently produced for sale in the U.S.are required to have the "Nutrition Facts" labeling. These guidelines ensure that nutrient claims mean the same on every product.

Serving Size: More consistent and realistic serving sizes, in both household and metric measures.
Calories & Calories from Fat: This new term helps consumers meet USDA Dietary Guidelines that recommend people get no more that 30 percent of their calories form fat each day. Remember, it’s your total consumption over the whole day, and not the percentage in one food or meal that’s important.
The list of nutrients covers those most important to the health of today’s consumers, most of whom need to worry about getting too much of certain nutrients such as fat, cholesterol, sodium, or sugars, rather than too few vitamins or minerals, as it the past.
%Daily Values: Use it to easily compare products and to quickly tell if a serving of a food is high or low in nutrients.
Daily Values: The daily values that have been set for certain nutrients are listed on larger packages for both a 2,000 and a 2,500-calorie diet. This information is based on current dietary guidance and can help you understand the basics of a good diet and plan healthy meals.
Calories per gram: This shows the calorie content of the energy-producing nutrients.
Ingredients are be listed in descending order of weight. The list is now required on almost all foods, even standardized ones such as mayonnaise and bread. The sources of some ingredients are stated by name to help people better identity ingredients that they avoid for health, religious, or other reasons.

Key
g = grams (about 28 grams = 1 ounce)
mg = milligrams (1,000 milligrams = 1 gram)

Source: United States Department of Agriculture