Serving Size

Always start with the serving size amount. That's because all the information on the rest of the label — from calories to vitamins — is based on that amount.

Take note of how much a serving is (e.g., 1 cup, 8 oz). Sometimes a serving size will be way less than you're used to eating — like only half a cup of cereal. So make sure you check what it is!

The label will also list how many servings are in the package. Even things that seem like they'd be a single serving, such as a bottle of juice or packet of chips, may contain more than one serving. If you eat or drink the whole thing, you're getting more vitamins and minerals but you're also getting way more calories, sugar, fat, and other stuff that you might not want.

Calories

A calorie is a way to measure how much energy a food provides to your body. The number on the food label shows how many calories are in one serving of that food. To get a rough idea of how many calories you need to eat each day, check out the “My Pyramid Plan” calculator on the U.S. government's MyPyramid website (see our Resources section for more information).

The calories from fat number tells you how many calories in that serving come from fat. For most people, no more than 30% of all the calories they eat in a day should come from fat. So if you eat 2,000 calories a day, no more than 600 of these calories should come from fat.

Percent Daily Value

These percentages show the amounts of nutrients an average person will get from eating one serving of that food. For the purposes of food labels, the government chose an “average” person as someone who needs 2,000 calories a day. So if the label on a particular food shows it provides 25% of vitamin D, that 25% is for a person who eats 2,000 calories a day.

But obviously some teens — like those who are growing rapidly or very athletic — will need more calories than 2,000 a day. And many will need less. If you need more than 2,000 calories, you may need to eat more than one serving to get the same percentage of that nutrient. If your calorie needs are less, you may not need to eat as much to get that same percent.

The percent daily value amounts are based on these nutrition guidelines:

The percent daily value information can be complicated. But one thing it makes easy is showing at a glance if a food is high or low in a particular nutrient. Here's how: If a food has a daily value of 5% or less of a nutrient, it is considered to be low in that nutrient. A food is a good source of a nutrient if the percent daily value is between 10% and 19%. If the food has 20% or more of the daily value, it is considered an excellent source of that nutrient.

Fat

Total fat shows how much fat is in a single serving of food. Although eating too much fat can lead to obesity and health problems, our bodies do need some fat every day. Fats are an important source of energy and provide insulation and cushioning for the skin, bones, and internal organs. Fat also distributes and helps the body store certain vitamins.

Fat is usually measured in grams. A good rule of thumb for keeping to the 30% calories from fat rule is to check the label and choose foods that have less than 3 grams of fat for every 100 calories in a serving.

Some fats are better than others. Unsaturated fats, which are found in vegetable oils, nuts, and fish, are often called “good fats.” That's because they don't raise cholesterol levels like saturated fats and trans fats do. Both saturated and trans fats are considered “bad” because they can increase a person's risk for developing heart disease. These types of fat are solid at room temperature (picture them clogging your arteries).

Saturated fats usually come from animal products like cheese, meats, and ice cream. Trans fats are naturally found in these foods too, but they are also in vegetable oils that have been specially treated (hydrogenated) so they are solid at room temperature — like shortening. The amount of saturated and trans fats that are in a food are shown below total fat on the nutrition facts label. Less than 10% of calories should come from saturated fats and keep trans fats low as possible.

Cholesterol

Cholesterol isn't entirely bad for you.  Keep in mind that it is important to the production of vitamin D and some hormones, and to building many other substances in the body. The liver manufactures most of the cholesterol a person needs.   Cholesterol is also found in the foods we eat. Blood cholesterol comes in two major types: HDL (the “good” kind) and LDL (the "bad" kind). Too much LDL cholesterol in a person's blood increases the risk of heart disease. So it's a good idea for even teens to watch how much cholesterol they eat, along with saturated and trans fats, which tend to raise levels of LDL cholesterol in the blood.

Sodium

Sodium is a component of salt. Almost all foods contain sodium because it adds flavor and helps preserve food. Processed, packaged, and canned foods usually have more sodium than freshly made foods.

Small amounts of sodium keep proper body fluid balance. Sodium also helps the body transmit electrical signals through nerves. But too much sodium can increase water retention and blood pressure in people who are sensitive to it.

Total Carbohydrate

This includes several types of carbohydrates, including fiber and sugar. The best sources of carbohydrates are fruits and vegetables, along with whole-grain foods like cereals, breads, and whole-wheat pasta. Most of your daily calorie intake should come from carbohydrates.

Sugars are found in most foods. When a food contains lots of sugar, the calories can add up quickly. Soda, snack foods and other foods that are high in added sugar are considered “empty calories” because they usually don't offer a lot of other nutrients.

Checking sugar quantities on labels can be really eye opening. Often there's way more than you'd expect. For example, sometimes manufacturers cut back on fat but add sugar to  food tasting good.a little label study, you may notice that some low-fat foods have nearly as many calories as their regular version!

Fiber, another kind of carbohydrate, helps keep your digestive system healthy. Fiber can also help reduce cholesterol levels. Best of all, fiber has no calories and it can help you feel full. So check the label and pick foods that have at least 3 grams of fiber per serving.

Protein

Most of the body — including muscles, skin, and the immune system — is made up of protein. If the body doesn't get enough fat and carbohydrates, it can use protein for energy. So be sure the foods you eat give you some protein.

Vitamins and Minerals

It goes without saying that you want to choose foods that are high in a variety of vitamins and minerals. Some of the most important for teens are vitamin A, vitamin C, B vitamins, vitamin D, calcium, and iron. Some vitamins — like vitamin C — are water soluble, which means that the body can't store them so they need to be consumed every day. 

Food labels can't tell you what foods to eat — you get to make that decision!

But they can help you find foods that taste good and treat your body right.

• salt, sugar and starch
• vitamins, minerals and amino acids
• veterinary drugs
• food packaging materials

Some food additives have been linked to hyperactivity in children such as: