Supermarket food package labels that say "sugar-free" or "salt-free" don't mean the product is without sugar or salt, "lowfat" doesn't mean it's low in fat, and "new" might be rather old.

Here, according to the current issue of American Health, are the legal definitions for a number of claims currently made on food labels and what hey mean to you:- SUGAR-FREE or SUGARLESS - A product labeled "sugar-free" or "sugarless" cannot have sucrose, or table sugar, added to it. However, it can contain sugar alcohol like sorbitol, which is equal to sucrose in calories.

- SALT-FREE or NO SALT ADDED - These terms mean no table salt (sodium chloride) was added during processing, but the product could have significant naturally occurring levels of sodium, or high levels from substances added for preservation, leavening or other purposes. Check the ingredients list for terms such as monosodium glutamate, sodium bicarbonate and sodium saccharin.

- LOWFAT - For most foods, "lowfat" means whatever the manufacturer wants it to mean. Milk products labeled "lowfat," however, must contain between .5 percent and 2 percent fat by weight. And lowfat meat must be no more than 10 percent fat by weight.

- NEW - Meat and poultry products can call themselves "new" only for six months unless, of course, the manufacturer has not used up all of the company's new labels in that time. In that case, they can be "new" for a year. Foods other than meat and poultry products can be "new" for as long as the product exists, if the manufacturer desires.

- CHOLESTEROL-FREE or NO CHOLESTEROL - While products labeled this way cannot contain any cholesterol, that doesn't mean they ever had any to begin with. Nor does it mean they are free from saturated fat, which health experts regard as more dangerous than dietary cholesterol when it comes to heart disease.

- LIGHT or LITE - On meat and poultry products, "light" means at least 25 percent less fat, sodium or breading or 25 percent fewer calories, than in the regular product. But on other foods, there is no standard meaning for "light" or "lite." The term can mean fewer calories, lighter color, less breading or anything else. One maker of pancake mix said "light" on its packages meant the pancakes were light in texture.

- DIET or DIETETIC - This one is well-defined. A product labeled "diet" or "dietetic" must contain 40 or fewer calories per serving or 33 percent fewer calories than the regular product.

- NATURAL - For meat and poultry, "natural" signifies there are no artificial colors, flavors, preservatives or synthetic ingredients. On packages of baked goods, beverages and other processed foods, the term doesn't have to mean anything at all.