Ever since man (and woman) came out of the caves, people have been making health claims for certain foods. These folk remedies may be comforting, but the evidence to support them is mostly anecdotal: “I had a cold. My mom gave me chicken soup, and here I am, all bright-eyed and bushy-tailed. Of course, it did take a week to get rid of the cold completely. . . .”

On the other hand, health claims approved by the USDA and the Food and Drug Administration (FDA) for inclusion on the new food labels are another matter entirely. If you see a statement suggesting that a particular food or nutrient plays a role in reducing your risk of a specific medical condition, you can be absolutely 100 percent sure that a real relationship exists between the food and the medical condition.

You can also be sure that scientific evidence from well-designed studies supports the claim. In other words, USDA/FDA-approved health claims are medically sound and scientifically specific. They highlight the known relationships between:

• Calcium and bone density: A label describing a food as “high in calcium” may truthfully say: “A diet high in calcium helps women maintain healthy bones and may reduce the risk of osteoporosis later in life.”

• A diet high in fat, saturated fat, and cholesterol and a higher risk of heart disease: A label describing a food as “low-fat, low cholesterol,” or “no fat, no cholesterol” may truthfully say: “This food follows the recommendations of the American Heart Association’s diet to lower the risk of heart disease.”

• A high-fiber diet and a lower risk of some kinds of cancer: A label describing a food as “high-fiber” may truthfully say: “Foods high in dietary fiber may reduce the risk of certain types of cancer.”

• A high-fiber diet and a lower risk of heart attack: A label describing a food as “high-fiber” may truthfully say: “Foods high in dietary fiber may help reduce the risk of coronary heart disease.”

• Sodium and hypertension (high blood pressure): A label describing a food as “low-sodium” may truthfully say: “A diet low in sodium may reduce the risk of high blood pressure.”

• A fruit-and-vegetable-rich diet and a low risk of some kinds of cancer: Labels on fruits and vegetables may truthfully say: “A diet high in fruits and vegetables may lower your risk of some kinds of cancer.”

• Folic acid (folate) and a lower risk of neural tube (spinal cord) birth defects such as spina bifida: Labels on folate-rich foods may truthfully say: “A diet rich in folates during pregnancy lowers the risk of neural tube defects in the fetus.”

Foods with more than 4 grams saturated fat and/or saturated fat plus trans fat per serving cannot have any health claims at all on their labels.

Today, savvy consumers reach almost automatically for packages labeled “low fat” or “high fiber.” But it’s a dollars-to-doughnuts sure bet that hardly one shopper in a thousand knows what “low” and “high” actually mean. Because these are potent terms that promise real health benefits, the new labeling law has created strict, science-based definitions:

• High means that one serving provides 20 percent or more of the Daily Value for a particular nutrient. Other ways to say “high” are “rich in” or “excellent source,” as in “milk is an excellent source of calcium.”

• Good source means one serving gives you 10 to 19 percent of the Daily Value for a particular nutrient.

• Light (sometimes written lite) is used in connection with calories, fat, or sodium. It means the product has one-third fewer calories or 50 percent less fat or 50 percent less sodium than usually is found in a particular type of product.

• Low means that the food contains an amount of a nutrient that enables you to eat several servings without going over the Daily Value for that nutrient.

• Low-calorie means 40 calories or fewer per serving
• Low-fat means 3 grams of fat or less
• Low saturated fat means less than 0.5 grams trans fat per serving and 1 gram (or less) saturated fat.
• Low-cholesterol means 20 milligrams or less

• Reduced saturated fat means that the amount of saturated fat plus trans fat has been reduced more than 25 percent from what’s normal for in the given food product.

• Free means “negligible” — not “none.”

• Calorie-free means fewer than 5 calories per serving.
• Fat-free means less than 0.5 grams of fat.
• Trans fat–free means the food has less than 0.5 grams trans fat and 0.5 grams saturated fat per serving.
• Cholesterol-free means less than 2 milligrams of cholesterol or 2 grams or less saturated fat.
• Sodium-free or salt-free means less than 5 milligrams of sodium.
• Sugar-free means less than 0.5 grams of sugar

Notice something missing? Right, there’s no definition for “low sodium” per serving. On the other hand, a meal plan with less than 1,000 milligrams sodium per day is considered a low-sodium diet.

The extra added attraction on the Nutrition Facts label is the complete ingredient listing, in which every single ingredient is listed in order of its weight in the product, heaviest first, lightest last. In addition, the label must spell out the true identity of some classes of ingredients known to cause allergic reactions:

• Vegetable proteins (hydrolyzed corn protein rather than the old-fashioned hydrolyzed vegetable protein)
• Milk products (nondairy products such as coffee whiteners may contain the milk protein caseinate, which comes from milk)
• FD&C yellow No. 5, a full, formal chemical name instead of coloring.

Naming the precise source of sweeteners (corn sugar monohydrate rather than just sugar monohydrate) is still voluntary, but as is true of information about raw meat, fish, and poultry, manufacturers and stores just may respond to consumer pressure.