Most food manufacturers are required to print a 'Nutrition Facts' panel on their food labels, but not all do, and they don't all look identical! You might find that some items, such as foods from small manufacturers, foods in small packages, and foods sold in bulk, don't even have one. In that case, try to scope out the ingredients list if there is one (More on that below).
In a nutshell, the Nutrition Facts panel lists important nutrition information for the food. Here's what you should pay special attention to:
Serving Size. Always check this number; it tells you the size of the serving that the other nutrition information on the label applies to. It is listed in a 'household' or common measure (like cups, slices or chips), as well as a weight measure. It not only tells you how many times to multiply your 'actual' serving to find out what was in the food you ate (e.g. You might find that a bag of chips that appears to contain one serving actually contains two — and twice the calories and grams of fat you bargained for), but it also allows you to compare similar products side by side. When comparing items of different shapes and sizes like bread and pasta, the weight measure is your best bet.
Calories. This is the number of calories in one serving of the food. The 'Calories from Fat' gives you the number (not the percentage) of calories in the food that comes from fat. Checking out the number of calories in foods allows you to budget your daily calories more effectively. Don't be fooled though, low calorie foods are not always healthy! Check the rest of the label. A serving of soup might appear to be innocently low in calories, but will scare your socks off with how much sodium it contains!
Nutrient list. The middle portion of the label lists the amounts of fat (total, saturated, and trans), cholesterol, sodium, carbohydrate (fibre and sugars), and protein. It also lists the amounts of vitamins A and C, iron, and calcium. (Other vitamins and minerals may appear as well, but they are not required.) Pay special attention to the amounts listed for Fat, Sodium, and Cholesterol.
Fats. The number listed next to 'Fat' should not immediately alarm you - not all fats are created equally! It is a good idea to keep the total number low, but you really want to pay special attention to getting as little saturated and trans fats as possible. These are the ones that are associated with poor health and disease. Mono- and Poly-unsaturated fats are the good kinds, so it is good if they make up most of the fats in the foods you're buying. But keep in mind that even though they're good, they're not a free-for-all. Limit your overall fat intake to only as much as you need to maintain a healthy weight.
Sodium. In a day, all you really need for good health is about 1500 mg, but as long as you keep your sodium intake below 2300mg per day, you're doing better than most.
Fibre. Aim to get 25-35 grams of fibre in your diet each day.
% Daily Value. Listed next to each nutrient is "% Daily Value," or the percentage in each serving of one day's recommended intake for that nutrient. This is a great little tool to help you compare food items and also gauge how much of each nutrient you're getting from that particular food. Keep in mind, however, that these percentages are based on a 2,000-calorie diet; if you eat fewer calories a day, then you're actually getting a larger percentage of your day's total fat, saturated fat, carbohydrate, and protein from each food.
The recommended dietary allowances of the other nutrients like vitamins and minerals are the same for all calorie levels, but keep in mind that the %DV for sodium is based on an intake of 2,400mg. This means that if the %DV of the sodium in your soup is 20% based on 2,400mg, and all you want is 1,500mg each day, that soup is really giving you 32% of your daily goal! An easy way to guesstimate that number is to multiply it by 1.5.
Label Claims. Generally, if a % Daily Value is less than 5 percent, the food is considered "low" in that nutrient. If the % Daily Value is greater than 20 percent, the food is considered "high" in that nutrient.
The Ingredient List. It is also important that you know why the ingredient order in the ingredients list matters. Ingredients are listed in order of percentage by weight. In other words, the first ingredient is what the product contains the most of; generally, you should pay the most attention to the first five ingredients. Beware if any of the first ingredients are: partially hydrogenated oil, High Fructose Corn Syrup (HFCS), and sugar (also known as glucose, sucrose, fructose, galactose, maltose, molasses, maltodextrin, and fruit juice concentrate). It is not recommended to consume these components in high quantities as part of a healthy diet.
And there you have it. With a good pair of glasses and some basic math skills, nutrition facts panels and ingredient lists really aren't all that scary. The information you get by reading them before you choose foods is really invaluable if you're trying to maintain good health. Realistically, isn't it scarier not knowing what's in your food?