Food labels don't lie. But if you're one of the 60% of people who rely on them to make healthy choices and you don't know what to look for, they can deceive.
Kathy McManus, RD, director of the department of nutrition at Brigham and Women's Hospital in Boston, offers five ways to be smart about grocery shopping.
Check the servings
If one package doesn't equal one serving, multiply the nutritional information by how much you're going to eat—especially calories: Packaged meals should contain no more than 400; snacks shouldn't exceed 150.
Be a serving size sleuth: Many bottled beverages contain 2-3 servings, so quenching thirst with a typical bottled iced tea means you'll consume 300 calories and 69 g of sugar. If you're trying to slim down, don't drink your calories; choose water frequently and enjoy a flavored beverage as a once-in-a-while splurge.
Limit bad fats
Pick products with zero trans fat and low saturated fat—women on a 1,600-calorie diet need no more than 13 g daily. Look at the labels especially for high-fat items like junk food, cheese, and some meats.
Be a saturated fat sleuth: Snacks like potato chips are notoriously high in saturated fats. When adding a side to your sandwich, opt for baked or whole grain chips instead.
Fill up on Fiber
Foods that contain 3 g or more can help reduce appetite and cholesterol.
Be a fiber sleuth: Just a 1/2-cup serving of Kellogg's All-Bran cereal for breakfast starts your day with 10 g of fiber!
taken from http://www.prevention.com/food/healthy-eating-tips/what-look-food-label