The large print on food labels focus on what are called macronutrients: carbohydrates, fat and protein. Some of the smaller categories convey information about vitamins, fiber, and minerals, as well as the totals of fat and saturated fat contained in food. So, you have no excuse for claiming ignorance about your diet: the truth is in the labels.

Food labels can be confusing to the uninitiated. Go into a big food store and you can be faced with what seems to be a forest of food information: more than 15,000 labels. Add to that fact that every year more than 30,000 new food products can be introduced to the marketplace, and what you're faced with is a jungle of food labels.

That overwhelming wealth of food label information doesn't mean you should throw up your hands in dismay and give up reading and deciphering labels. You should arm yourself against that sea of labels with knowledge and, by understanding them, end your confusion and build your health.

Label History
A hundred years or so ago, food labels were only required to list the name of the food contained inside the package. The contents, quality and processes used to make the food were often a mystery. Little or no disclosure to consumers was made about how their food was created.

By the early 1920s, the federal government, via the Food and Drug Administration (FDA), began requiring food companies to list the net weight of food on labels as well as the names and addresses of food processors and distributors. Finally, by the 1970s, listing basic nutritional information was mandated in a uniform way so that shoppers could have some basis for comparing foods.
Then, in 1990, the Nutrition Labeling and Education Act made major alterations to the kinds of labels that had to be included on food packages.

The FDA and the US Department of Agriculture (USDA) required significant changes to food labels that were supposed to make it easier for consumers to eat healthier diets. The labels requirements of 1994 included five major changes:
• The nutrition information on the label had to be printed in larger, more legible type.
• This condensed information had to be on the back or side of food packaging and titled as "Nutrition Facts." This type of information is also shown in grocery stores near the fresh food displays of fish, fruits and vegetables.
• The label had to include a column of information tagged as the "% Daily Value," designed to help consumers understand how the food could fit into a healthy diet.
• Each label had to include information about fat, cholesterol, fiber, sugar, calories from fat, and other information relevant to designing a healthy diet.
• The computed serving sizes were supposed to be more realistic and reflect the amount of food people actually eat at one sitting.

Label Questions
Consumer questions regarding food labels have led researchers to look into ways to help shoppers comprehend what food labels tell them. These studies are designed to help consumers match up their nutrition requirements with the foods they buy.

For instance, at the University of Illinois at Urbana-Champaign, scientists have devised a label tool called See It, Do It, Teach It to help people improve their diets through comprehension of food label information. " One of the goals of the project was to help...teenaged girls and menopausal women understand how they can get the daily requirement for calcium into their diet in order to help prevent osteoporosis," says Karen Chapman-Novakofski, PhD, associate professor and nutritionist in the school's College of Agricultural, Consumer and Environmental Sciences.

According to the See It, Do It, Teach It program, you should think of food labels as consisting of two sections:
• Food items you should limit: total fat, saturated fat, cholesterol, sodium and, if you're eating a low-carb diet, total carbohydrates
• What you may need to increase: vitamin A, vitamin C, calcium and iron

" Much more attention has been paid to what people should limit rather than the nutrients needed. The average consumer doesn't know, for instance, how much vitamin A 10% of the Daily Value is, or how much calcium 25% of the Daily Value is," Dr. Chapman-Novakofski says.

Upping Calcium Intake
In their eight-week study of people's calcium consumption (Journal of Nutrition Education and Behavior 4/04), the University of Illinois research team found that people didn't know how much calcium was in the food they ate.

After the initial part of the study, in which participants were shown how to look for calcium on labels, "the post-test revealed that the participants significantly increased their calcium intake to 821 mg per day, up from 372 mg per day," notes Dr. Chapman-Novakofski.

" That's a lot closer to the daily requirements of 1,200 mg per day for men and women over 50, 1,000 mg for men and women aged 19 through 50 and 1,300 mg per day for [youths aged] 9 to [18] years," she adds.

Parts of the Label
The first item at the top of a nutrition food label tells you the portion size that the label measures. An important point to remember: these sizes are determined individually by each manufacturer. Consequently, all of the other values on the label are measured per portion.

So, if you are comparing foods made by two different companies that employ very different portion sizes in their nutritional calculations, your label comparisons may be complicated.

Another fact to be aware of: the listed portion size may be an odd division of the food within the container and not reflect a common-sense division. For instance, some food packages are labeled as containing 2.5 portions.

And, to make things even more interesting, small boxes of candy that you might think contain barely enough for one helping may be labeled by the manufacturer as having two or more portions. As a result, if you eat the whole box, you often have to at least double the number of indicated calories, etc. to figure out the nutrients and calories you are consuming.

The section of the label that notes calories, calories from fat and percent daily values is listed under the portion size. Here you are told how many calories you consume when you devour one portion and how many of those calories are derived from fat.

This label focus on fat originated when consumers and dietitians were very concerned about Americans' fat consumption and hadn't yet switched their focus to carbohydrate consumption as a prevalent dietary health priority.

Also included on the label: the daily value percentages aimed at showing you how much out of a total day's intake of various nutrients a portion bestows upon you.

These percentage numbers are based on a theoretical analysis of a diet that contains 2,000 or 2,500 calories a day. (A notation at the bottom of the label tells you whether the calculation is based on 2,000 or 2,500.)

Carb Facts
If you've been eating a low-carb diet (or are planning this type of diet), the section of the label that lists carbohydrates may be especially useful. Under this heading, the label lists the totals for fiber and sugar.

No matter what diet you are on, dietary fiber is desirable, since it represents indigestible carbohydrates that both pass through you without conveying any calories and keep beneficial bacteria in your digestive tract healthy.

Most people want to limit their sugar totals, however, since this nutrient may raise your risk of being overweight and, when you eat a lot of it, may contribute to immune problems.

Interestingly enough, when food chemists compute what is in food, they perform lab tests known as assays to distinguish its ingredients. (The manner in which these tests are performed are very strictly regulated by the FDA.)

In fact, just about every nutrient listed on a food label is determined by laboratory test except for the carbohydrate content: the amount of water, fat, crude protein and ash are determined this way. But the total carbs are computed by simply subtracting the total of the other ingredients from the total amount of food, a kind of process of elimination.

So while fat and protein are measured with precise lab tests, carbohydrate totals are figured by the leftovers. (The water and ash, by the way, are not usually listed on food labels.)

Within the general carbohydrate group, are several categories of carbohydrates that produce very different effects in your body. These categories can be divided into sugar, sugar alcohols, dietary fiber and a collection of various chemicals that include organic acids, flavonoids, gums, lignans and others.

According to the FDA, the food label only has to list the total carbs, sugar and dietary fiber. But some food companies now list things like sugar alcohols.

Blood Sugar Effects
Not all of these types of carbohydrates behave the same way in your body. For example, when your body digests table sugar, it turns immediately into blood sugar. So sugar and most other carbohydrate is what we call "digestible carbohydrate." Other carbs, such as sugar alcohol or glycerine, can be digested but do not turn to blood sugar. Still others, such as dietary fiber, are indigestible and pass through your body without impacting your blood sugar level.

To date, the FDA has not focused on these important biochemical differences and treats all carbohydrates alike. This means that when you look at a food label, you do not see a number for the carbs that impact your blood sugar level. To do so, simply subtract the number of grams of fiber from the total number of carbohydrate grams.

Net Carbs
Recently, the phrases "low carb," "net carb" and "impact carbs" have begun to appear on food labels. These are not defined by the FDA; they were put on labels by by companies to help consumers pick out foods that are acceptable on low-carb diets.
To arrive at the total of net carbs, food companies subtract the total amount of fiber and sugar alcohol from the total carbohydrates.

Fiber Calculations
Since the body cannot digest fiber, this nutrient (which is still important for good health) is not calculated into the total amount of carbohydrates. As for sugar alcohols, while-technically speaking-these are carbs and they do have calories, they have little effect on blood sugar and usually are not counted in total carbohydrates.

According to the American Dietetic Association, people with diabetes who are managing their blood sugars using the carbohydrate counting method should "count half of the grams of sugar alcohol as carbohydrates since half of the sugar alcohol on average is digested.

" Fiber is not digested, however. If the serving of food has more then 5 grams of fiber one should subtract the grams of fiber from the total carbohydrate grams." As you can see, when it comes to food, as in most things, knowledge is power. If you want power over your health, you need power over the food you eat. The road to that power is by reading food labels. What's in the food you're eating every day may surprise you.