Learning labelese.

A "low fat" food can have no more than 3 grams of fat per serving. So how come this Cheese Cannetloni, which has 8 grams of fat, is labeled "low fat"?

It's an entree, my dear Watson. The 3-gram role applies only to individual foods.

Entrees and dinners are allowed 3 grams of fat for every 100 grams (3 1/2 ounces) they weigh. in other words, they get a free ride. (The same is true for other claims, like "low saturated fat" and "low sodium.")

This Cannelloni weighs about 9 ounces, so it's allowed around 8 grams of fat. That's awfully lenient considering that its 270 calories aren't much more than you'd get in a fruit-flavored yogurt.

The rule might make sense if there weren't any entrees or meals with only 3 grams of fat. But the supermarket is loaded with them.

"See back panel for information on sodium & other nutrients," says the extremely skinny type on Borden Fat Free Cheese Product. That may sound like friendly advice. In fact, it's a disclosure that the law requires on flawed foods that make good-sounding claims like "fat-free."

Don't confuse this disclosum with "see back panel for nutrition information." That's required on all foods that make a claim, period.

But if the disclosure names fat, saturated fat, sodium, or cholesterol, that means the food's got more than 20 percent of the Daily Value. In other words, it's high in that nutrient.

There are some unfortunate exceptions to this rule. No disclosure is required for a food that's high in sugar, like the Hostess Low Fat Crumb cakes.

And no disclosures are required for foods that contain meat and poultry, like the Hormel Light & Lean Franks (which are high in sodium). That's because they're regulated by the USDA, which adopted most, but not all, of the FDAs regulations.

Read the old label on Libby's Cherry Juicy Juice and you'd think you're drinking mostly cherry juice. Only by checking the small print on the ingredient list would you discover that it's got more apple and grape juice than cherry juice.

No more. The new label on Welch's Orchard Apple Grape Cherry 30% Fruit Juice says "great cherry taste" in the corner, but the name tells you that it's got more apple and grape juice than cherry juice.

That's because the new rules require each juice in a "blend" to be listed from most to least on the front label. But there are several exceptions. If the label says "strawberry flavored," for example, that means you're getting only a tiny amount of strawberry juice. It may not seem like much, but this cautious,

unsensational sentence represents a revolution in food labeling. Until 1984, if a food label mentioned a disease like cancel the FDA considered the food to be a non-approved drug in other words, illegal.

It's taken a decade to come up with rules for making these "health claims." So far, the FDA has approved claims for:

* fat and heart disease or cancer,

* fiber-containing grains, fruits, and vegetables and heart disease,

* fruits and vegetables rich in fiber, vitamin A, or vitamin C and cancer,

* sodium and high blood pressure,

* calcium and osteoporosis, and

* folic acid and birth defects.

You needn't memorize the list. Just remember that no food can make a health claim if it's high in the Daily Value for fat, saturated fat, sodium, or cholesterol.

And criteria for specific claims are even stricter. To make a "helps prevent heart disease" claim, for example, a food must be low in fat, saturated fat, and cholesterol.

There's also what's known as the "jellybean rule," which prohibits health claims on junk foods like candy and soft drinks.

So look for health claims. They're informative and, except for when they appear on frozen meals and entrees--which only have to meet very loose criteria--they're a good sign that you're getting a decent food,

See the words "Cholesterol Free Food" in the upper right corner? The presence of the word "food" means that the product is naturally cholesterol-free. Only when a company takes the cholesterol out of a food (like cheesecake) that usually contains cholesterol can the label simply say "cholesterol free." Ditto for "sodium tree," "fat tree," etc.

As for the vitamin E and betacarotene claims: It doesn't hurt to get a little extra of each in your diet, but that's just what you get here--a little.

There's only 8 mg (8 IU) of vitamin E. That's 25 percent of the DV, so it exceeds the 10 percent minimum required to mention a nutrient on the front of a label. But it's only a fraction of the 100 mga day that may reduce the risk of heart disease (see NAH, Jan./Feb. 1994, p. 8).

And the 350 IU of beta-carotene is far less than the 25,000 IU or so that people are taking in many studies on heart disease or cancer.

What's a "lean" food?

The regulations are quite liberal. Any food can be called lean if it has no more than 10 grams of fat, 4.5 grams of saturated fat, and 95 milligrams of cholesterol.

These Lean Pockets, for example, have 9 grams of fat. Four of them are saturated. That's not "low" in fat, despite the "Low Fat" claims on this old (pre-May 1994) label.

"Lean" claims are useful only when they appear on fresh cuts of

meat or poultry. In fact, that's why they were originally estab- lished-to help people identify lower-fat fresh meats, even the leanest of which would be too fatty to make a "low-fat" claim.

So ignore "lean" claims, except on fresh meat and poultry, where you're even better off with cuts that make an "extra lean" claim. They have no more than 5 grams of fat and 2 grams of saturated fat.