If you've ever tried, you're probably aware that it's quite time-consuming and challenging to count calories, fat grams, carbohydrates or anything else. But that doesn’t mean you shouldn’t pay attention to the Nutrition Facts labels on food packaging. If you have a hard time making heads or tails of food labels, take our cheat sheet with you the next time you hit the grocery store. Bonus: Understanding the labels will ensure that you are getting enough daily nutrients, which will help you reach your health and weight-loss goals.

• Serving size and servings per container. The serving size and number of servings in the package are the first things to look at when you are scanning a Nutrition Facts panel. Serving sizes are standardized by product type to make it easier to compare similar foods; the serving sizes are provided in familiar units, such as cups or pieces, followed by the metric amount (e.g., number of grams). It’s important to be aware of how many servings there are in a package. Many products that look like they contain 1 serving actually contain more than that in a single package. 

• Calories and calories from fat. Calories are a measure of how much energy you receive from a serving of the product. It's good to be aware of how many calories are in a serving size. It’s also useful to see how many of those calories come from fat. If it’s more than half, you should check how much saturated and trans fats are in a serving, which you’ll find farther down on the label (see the info on total fat below). 

• Daily value %. The right side of the panel lists the percent of the daily value for each nutrient that is provided in one serving. The percentage is based on 2,000 calories a day; as the label points out, your recommended daily value may be higher or lower depending on your calorie needs. 

• Total fat. This section is broken down into saturated and trans fat content. Manufacturers are not required to list unsaturated fats; however, unsaturated fats are included in the total fat calculations. Avoid products with 20% or more of the daily recommended value of saturated fat, as well as products that contain any trans fats. Be aware that a label can indicate 0% trans fats if the product contains less than 0.5 gram per serving — so be sure to check for hydrogenated or partially hydrogenated oils (which indicate the presence of these bad fats) in the ingredients list. 

• Cholesterol and sodium. You should discuss your situation with your physician, particularly if you have high cholesterol or high blood pressure and are salt sensitive. But look for foods that are low in sodium and cholesterol. 

• Total carbohydrates (dietary fiber and sugars). The total carbohydrated amount is the sum of total grams of dietary fiber and sugars. Eating plenty of fiber is very important (25–30 grams daily is optimal), so pay close attention to the dietary fiber subcategory on the label. When choosing whole grain breads, for example, select those that contain at least 3 grams of fiber per serving. When it comes to sugars, be aware that the number in this subcategory is the sum of sugars that occur naturally in foods (e.g., lactose and glucose) and added sugars (e.g., corn syrup, dextrose, high-fructose corn syrup, and honey). Take a peek at the ingredients list to check for these added sugars—avoid products made with them. 

• Vitamins and minerals. Manufacturers are required to list the percentages of the daily values of vitamin A, vitamin C, calcium and iron supplied by a serving of food. Listing other vitamins and minerals is voluntary, unless a claim is made about the nutrient or the vitamins and minerals are added to supplement the product (as in breakfast cereals that supply 100% of your daily need for various vitamins and minerals). If a food supplies less than 2% of the daily values for required nutrients, the values do not have to be listed.

Source http://southbeachdiet.com/sbd/publicsite/how-to-read-nutrition-labels.aspx