1. Look at ingredient lists: they’re the core of the label. Ingredients are listed in order of weight. You should carefully check ingredients for contents like partially hydrogenated and hydrogenated oils, as these signify the presence of trans fats. Fortunately, it’s getting easier and easier just to find brands that have no hydrogenated fats among the ingredients. Also look for added sugars (see above) and whole grains—the label must say “whole,” not just “wheat flour.”
2. Starting from the top of the label, look at the serving size. These are often unrealistically small. If you eat more than what the serving size indicates, you need to multiply all nutritional contents accordingly.
3. Next is the number of calories per serving, and the calories from fat. The total number of calories is very important if you’re attempting to control your weight. The calories from fat is less important. Much more important is the type of fat.
4. Further down you will find the total fat per serving and the grams of saturated, trans, polyunsaturated and monounsaturated fats. Amounts are rounded to the nearest whole number, so 0.4 gram would be listed as 0 grams, 0.8 gram would be listed as 1 gram. You want to limit your saturated fat to 5 percent or less of your total calories (divide your body weight by 12 to get the total daily limit of saturated fat in grams).
5. As for trans fats, you want to limit intake entirely. Polyunsaturated and monounsaturated fats are healthy, so no limitation is needed other than if you are limiting calories.
6. Further down is cholesterol content. This number is largely irrelevant as your blood cholesterol levels depend more on saturated-fat and trans-fat intake than on cholesterol intake. Ignore this one.
7. Then there’s carbohydrate content and, unfortunately, current rules do not require labels to distinguish whole grains from processed grains. The label does give information on dietary fiber. As a rule of thumb, men should take in more than 38 grams of total fiber per day and women should take in more than 25 grams of total fiber.
8. Sugar is next; less is better. The label does not distinguish between natural and added sugars, so check the ingredients list to spot added sugars—a frequent culprit is high-fructose corn syrup.
9. And finally, protein is listed as total protein. Chances are, your protein intake is adequate, and I usually don’t suggest tallying it.
10. At the extreme right of the label you’ll see each nutrient’s percentage of your total daily intake based upon the guess that you take in 2,000 calories a day. Since this amount of calories would be appropriate only for an individual weighing 166 pounds, this section is quite useless if you don’t happen to weigh 166 pounds. Instead, focus on the actual grams or milligrams of the nutrients in question.


Source:  http://www.eatingwell.com/blogs/health_blog/deceptive_food_labels_how_to_know_what_s_truly_healthy