Read the nutrition facts
The first place to start when you look at the Nutrition Facts label is the serving size and the number of servings in the package. Serving sizes are standardized to make it easier to compare similar foods and are provided in familiar units (such as cups or pieces ) followed by the metric amount.
The size of the serving on the food package influences the number of calories and all the nutrient amounts listed on the top part of the label. Pay attention to the serving size, especially how many servings there are in the food package. Many products that appear to be a single serving actually are labeled as multiple servings.
Calories provide a measure of how much energy you get from a serving of this food. Many Americans consume more calories than they need without meeting recommended intakes for a number of nutrients. The calorie section of the label can help you manage your weight. The number of servings you consume determines the number of calories you actually eat (your portion amount).
The nutrients listed first are the ones Americans generally eat in adequate amounts, or even too much. Eating too much fat, saturated fat, trans fat, cholesterol or sodium may increase your risk of certain chronic diseases, like heart disease, some cancers, or high blood pressure.
Most Americans don't get enough dietary fiber, vitamin A, vitamin C, calcium and iron in their diets. Eating enough of these nutrients can improve health and help reduce the risk of some diseases and conditions.
The percent Daily Values (%DVs) are based on the Daily Value recommendations for key nutrients but only for a 2,000 calorie daily diet - not 2,500 calories. You, like most people, may not know how many calories you consume in a day. But you can still use the %DV as a frame of reference whether or not you consume more or less than 2,000 calories.
The %DV helps you determine if a serving of food is high or low in a nutrient. Note: a few nutrients, like trans fat, do not have a %DV - they will be discussed later.
Do you need to know how to calculate percentages to use the %DV? No, the label (the %DV) does the math for you. It helps you interpret the numbers (grams and milligrams) by putting them all on the same scale for the day (0-100%DV). The %DV column doesn't add up vertically to 100 percent. Instead each nutrient is based on 100 percent of the daily requirements for that nutrient (for a 2,000 calorie diet). This way you can tell high from low and know which nutrients contribute a lot, or a little, to your daily recommended allowance (upper or lower).