Nutrition Labels Explained

Since 1994, most packaged food items sold in the U.S. have been required by the FDA to contain a "Nutrition Facts" label on the packaging. There are strict guidelines as to the format and appearence of these labels, depending upon package size and the type of food product sold. The guidelines are designed to reduce the amount of confusion that existed previously, as voluntary compliance on food labeling prior to 1994 did not provide for much consistency among various brands and products.

The mandatory (boldfaced) and voluntary dietary components and order in which they must appear are:

• total calories
• calories from fat
• calories from saturated fat
• total fat
• saturated fat
• stearic acid (on meat and poultry products only)
• polyunsaturated fat
• monounsaturated fat
• cholesterol
• sodium
• potassium
• total carbohydrate
• dietary fiber
• soluble fiber
• insoluble fiber
• sugars
• sugar alcohol (for example, the sugar substitutes xylitol, mannitol and sorbitol)
• other carbohydrate (the difference between total carbohydrate and the sum of dietary fiber, sugars, and sugar alcohol, if declared)
• protein
• vitamin A
• percent of vitamin A present as beta-carotene
• vitamin C
• calcium
• iron
• other essential vitamins and minerals.

Total Calories

A dietary calorie is actually a kilocalorie (kcal), in physical terms, meaning 1000 actual calories. A calorie is defined as the amount of heat needed to increase the temperature of one gram of water by one degree Celsius. A dietary calorie, therefore, is the amount of heat contained in food that can raise the temperature of one liter of water (1000 grams) by one degree Celsius.

The calories listed on food labels are the effective energy that food can provide to the body, allowing for energy that is wasted in the digestive process etc. The gross energy value of foods is always higher than that listed.

For formulated foods, calorie values generally reflect industry practices (as permitted by the Nutrition Labeling and Education Act) of calculating calories from 4-4-9 kcal/g for protein, carbohydrate, and fat, respectively or from 4-4-9 kcal/g for protein, carbohydrate minus insoluble fiber, and fat. The latter method is frequently used for high-fiber foods.

Notice that this apparently presents an opportunity for inconsistency in labeling among different food products and companies. Some food items may include the dietary fiber in the calculation of total calories; others may not. In the sample label shown on this page, fiber is included in the calculation for total calories.

Sugar alcohols are generally less digestible than other carbohydrates and can be counted as approximately two-thirds the caloric value of sugar, or about 2.7 kcal/g.

Other ingredients in some foods that can add to the caloric value are alcohol, organic acids, and glycerin.

Rounding

For foods that have servings containing fewer than 50 calories, the "Total Calories" can be rounded to the nearest 5-calorie increment. So, for example, a food product in which a serving size contains 1g of fat, 3g of carbohydrates, and 2g of protein, the actual caloric value would be 29. The nutrition label would thus show total calories of 30.

Foods that have more than 50 calories per serving must have a label that rounds "Total Calories" to the nearest 10-calorie increment. A serving of such a food that actually contains, say, 96 calories would show a total calorie count of 100 on the label.

Fat, saturated fat, total carbohydrates, sugars, and dietary fiber must be rounded to the nearest whole gram. Heavy whipping cream, for example, has a serving size of 1 tablespoon and an actual carbohydrate content of about .4 grams. The label can, therefore, show the total carbohydrates as 0.

If the total carbohydrate count is less than one but more than .5g, the label should list the total carbohydrates as "less than 1" or <1.

People on low-carbohydrate diets should take into account these "hidden carbs" when deciding how much of a certain food item to consume.

It Doesn't Add Up!

Because of rounding, and especially because of the manner in which the amount of carbohydrates is calculated, sometimes the various carbohydrate amounts do not add up correctly. In other words, the "Total Carbohydrate" amount might be greater than the number of grams of dietary fiber, sugars, and other carbohydrates added together.

The regulations require that the number of grams of "Total Carbohydrate" be derived from a process known as the "carbohydrate by difference method." What it means is that the water, total fat and protein amounts are determined by chemical assay. What is left over must be carbohydrates. In actuality, this method is not always accurate because some of these "left-over" constituents may not be carbohydrate material. In addition, for products such as yogurt that contain live bacterial cultures, which consume sugar, the total carbohydrates are always substantially less than what the label reports.

Serving Size

The FDA defines serving size as the amount of food customarily eaten at one time. It is based on FDA- and USDA-established lists of "Reference Amounts Customarily Consumed Per Eating Occasion."

These reference amounts, which are part of the current regulations, are broken down into 139 FDA-regulated food product categories, including 11 groups of foods for children under 4, and 23 USDA meat and poultry product categories. They list the amounts of food customarily consumed per eating occasion for each food category, based primarily on national food consumption surveys. FDA's list also gives the suggested label statement for serving size declaration.

For example, the category "breads, rolls" has a reference amount of 50 g, and the appropriate label statement for sliced bread is "__ piece(s) __ (g)" or, for unsliced bread, "2 oz (56 g/__ inch slice)."

The serving size of products that come in discrete units, such as cookies, candy bars, and sliced products, is the number of whole units that most closely approximates the reference amount. For example, cookies have a reference amount of 30 g. The household measure closest to that amount is the number of cookies that comes closest to weighing 30 g. Thus, the serving size on the label of a cookie package in which each cookie weighs 13 g would read "2 cookies (26 g)."

If one unit weighs more than 50 percent but less than 200 percent of the reference amount, the serving size is one unit. For example, the reference amount for bread is 50 g; therefore, the label of a loaf of bread in which each slice weighs more than 25 g would state that a serving size is one slice.

For food products packaged and sold individually, if an individual package is less than 200 percent of the applicable reference amount, the item qualifies as one serving. Thus, a 360-milliliter (mL) (12 fluid-ounce) can of soda is one serving because the reference amount for carbonated beverages is 240 mL (8 fluid ounces).

However, if the product has a reference amount of 100 g or 100 mL or more and the package contains more than 150 percent but less than 200 percent of the reference amount, manufacturers have the option of deciding whether the product is one or two servings.

For example, the serving size reference amount for soup is 245 g. So a 15-ounce (420 g) can can be listed as either one or two servings.