(MONEY Magazine) – Remember when "sugar" was a grrreat word to have on a food label? Not anymore. These days, labels entice you with the promise of diet-conscious, healthy eating. Don't always believe what you read there, however. Sure, the government regulates much of what labels can say, but plenty of loopholes remain. Here's what you should know:

--According to Food and Drug Administration rules, if a label says "fat-free," the food must have "physiologically inconsequential" amounts of fat: less than 0.5 grams per serving. But while fat-free foods are healthier for you than fat-soaked alternatives, don't think of them as diet fare you can gorge on. For example, though the package boasts "35% less calories than the leading cookie," Nabisco's fat-free SnackWell's Devil's Food Cookie Cakes still have 50 calories apiece. "Whether it comes from protein, fat or carbohydrates, a calorie is a calorie is a calorie," says Ann Grandjean, director of the International Center for Sports Nutrition.

--To be described as "light," food usually must have a third fewer calories or half the fat of the same volume of food prepared with traditional ingredients--and the packaging must say so. But there are exceptions. Foods that have generically been known as light (for example, light cream as opposed to heavy cream) do not have to conform, so a food in "a light cream sauce" may not meet the FDA's fat and calorie standards. And certain general descriptions such as "lightly sweetened" are not regulated by the FDA.

--Healthy as they may sound, the descriptions "natural" or "all natural" mean only that the products have no synthetic or artificial ingredients. But they still can be loaded up with stuff like sugar.

--Generally, "organic" means that a processed food does not contain additives like sulfites or nitrates and that fresh produce is farmed without synthetic pesticides or fertilizers. But only 30 states regulate organic food production. Your best bet with organics: Buy only those products labeled "certified," which assures that they have passed an inspection by a state agency or an independent auditor. A federal law that will standardize the certification process for organic foods is expected to be implemented next year.

--By Food and Drug Administration standards, food labeled "healthy" must be low in fat (three grams or less per serving) and saturated fat (one gram or less), and have little sodium (480 milligrams maximum) and cholesterol (60 milligrams max). It must also provide at least 10% of the FDA's recommended daily dosage of any one of the following nutrients: vitamins A and C, calcium, iron, protein or fiber. But a product labeled "healthy" doesn't necessarily promote good health. It can still contain ingredients like sugar and chemicals. The bottom line: Look beyond the sizzle on any label and read the fine print for a rundown of exactly what's inside the package.

--Susan Berger