When you reach for a product that is "reduced calorie," "cholesterol-free," "low-fat" or "lower in oil," do you really know what you're buying?

Irene Yeh, a registered dietitian and senior consumer food specialist at the Quaker Oats Co., says claims on product packages may not always be representative of the product's total nutritional value.Consumers should read the product's entire label before buying, she says. Among her guidelines:

- Don't assume that a "lite" product is necessarily low in calories. According to the Food and Drug Administration, a product can claim it is "lite" for a number of reasons - so long as these reasons are specified on the packaging. So, a "lite" product containing less oil does not necessarily have fewer calories.

- Not all serving sizes are the same. Be especially aware of serving sizes on snack foods. What you may think is a single-serving bag could be two or more servings.

- Watch out for products that are low in fat but have a high percentage of saturated fats. Manufacturers are not currently required to list on the label the amount of saturated fats, which include animal fats, tropical oils, butter or lard, on the label.

- Be cautious of cholesterol claims. A product can be labeled "cholesterol-free" and still contain a high amount of saturated fats.

- Survey the sodium content. Many "lite" products make up for lack of flavor with extra salt. Look for products with a per-serving sodium content of 140 milligrams or less.