How much attention do you pay to nutrition labels? Do you count calories? Do you try to buy foods that are iron or calcium enriched? The nutrition label on most foods can be an important source of information for many people about what they’re eating.

But as it turns out, nutrition labels are not as trustworthy as they seem. Not only are they often misleading, but they can be downright incorrect. And much of this stems from what the original purpose of nutrition labels was.

During World War II, the American government was faced with a dilemma: during a time of shortage and rationing, how were they going to keep their soldiers healthy on the war front? They needed to develop a way to make sure every soldier was getting the nutrition he needed—in other words, enough of the right kinds of food. So in 1941 the National Academy of Sciences developed the Recommended Daily Allowances (RDAs).

 You’ve seen these RDAs before. On a nutrition label, they take the form of percentages—in other words, what percent of the RDA of that particular nutrient is contained in one serving of that food. These nutrients include vitamins and minerals such as Vitamin A, Vitamin C, and iron. People who are trying to eat nutritious diets often turn to the nutritional facts label on their food for information on what they’re eating.

For example, by drinking one serving of milk (i.e., one eight ounce glass), Joe is getting 30% of his daily calcium. But think about this for a second. Where is this “30%” coming from? Say Joe is a 6’5” football player. When Rosa, who is 5’5” and half his weight, drinks that same glass of milk… is she also getting 30% of her daily calcium needs? Then there are other things to consider, such as age and activity level. Basically, the RDA is based off the “average” person—and very few people exactly fit that mold.

And that’s not all. Because the RDAs were originally designed to supply the minimum amount of nutrients necessary—a basic rule of thumb the RDAs still follow—the RDAs only supply enough nutrients to keep you from getting nasty diseases like scurvy (caused by severe vitamin C deficiency).  The RDAs were about survival, not long-term health. Even today the numbers used in the RDAs are about supporting basic health from day to day and preventing malnutrition. Think of the RDAs as a crutch to keep you propped up—wouldn’t it be much better to be able to stand on your own feet? The RDAs do not protect against the slow onset of degenerative diseases such as cancer or arthritis, serious concerns in modern times, the way an optimal nutrition program can.

Because of this, many people think that they are getting a large amount of vitamin C from their 10% orange juice, when they are really getting only a very small amount that probably isn’t enough to keep them healthy.

So not only are you getting less nutrition than the “average person” needs to stay healthy, you’re probably getting nowhere near the amount of nutrients your individual body needs. For example pregnant women require 400 micrograms of folic acid to prevent certain birth defects, but the RDA remains stuck at just 180 micrograms. The RDA also does not account for people with chronic diseases or disorders, who often need additional supplements. Some nutrients do not have an RDA at all, simply because not enough is known about what harm a deficiency in that nutrient could cause.

The RDA has been updated periodically, but the basic idea behind it has stayed the same. And it hasn’t been updated since 1989 at all. The 1989 levels were actually lowered in many cases from what they had been in 1980. For example, the 1989 RDA for folic acid was reduced from 400 to 200 mcg. Why? Because the average American was consuming less than the recommended amounts, and they wanted the RDAs to reflect what people actually consumed—after all, since the American people were still functioning and healthy, the amounts they were eating must be all

that was necessary. Yes, that was the logic.

RDAs aren’t the only misinformation nutrition facts labels contain. You may have heard about how trans fats are now a required item on the label. But what you probably don’t know is that if there is less than 0.5 grams of trans fat per serving, the food companies can list that as 0 grams, and are free to label and advertise their foods as “trans fat free.” And don’t forget those magic words, “per serving.” That means that all the manufacturer has to do is reduce the serving size to a point where the amount of trans fat is 0.5 grams or less, and voila, trans fat free food.

Many foods that seem to be trans fat free, then, are actually not. Many packaged baked goods and fried foods contain trans fat. And trans fat is in no way, shape or form good for you. It clogs arteries, causes diseases, and spurs aging. Additionally, most Americans consume more than one serving of a food in a sitting. Even if you think you’re eating a food that’s low in whatever it’s advertising, you have to remember to multiply that by how many servings you’re consuming. You could be eating a “trans fat free food,” and really be loading up on trans fats.

What you need to do is look at the ingredients. Anytime you see the words “hydrogenated” or “partially hydrogenated,” it means that food contains trans fat. So don’t let the label fool you. Stay smart about what you’re eating.

The bottom line is, you can’t rely on food labels to address your personal nutrient needs. Instead of using the percentages given, it would be more informative to calculate the actual amounts of vitamins and minerals you are getting and apply them toward your overall needs. A multivitamin is a good way to supplement that, since it can be very difficult to meet all your nutritional needs through meals in today’s fast-paced world.

So changes need to be made to the RDAs, to bring them up from the bare minimum to the optimal levels—that much is clear. But what are those levels? There is an ongoing debate on what to change the RDAs to. Some questions under consideration include: What are the RDAs meant to do? What happens when there isn’t enough research to know what the right amount is? What about groups that aren’t included in trials, like children and the elderly? In many cases, there isn’t enough scientific knowledge about what levels of nutrients are most optimal. Should there also be a maximum value as well? Several values, like the U.K. system?

The bottom line is that, at least right now, nutrition facts label cannot be relied on for complete nutritional help. You have to take control of your own health.