Because of spam, I personally moderate all comments left on my blog. However, because of health issues, I will not be able to do so in the future.

If you have a personal question about LI or any related topic you can send me an email at I will try to respond.

Otherwise, this blog is now a legacy site, meaning that I am not updating it any longer. The basic information about LI is still sound. However, product information and weblinks may be out of date.

In addition, my old website, Planet Lactose, has been taken down because of the age of the information. Unfortunately, that means links to the site on this blog will no longer work.

For quick offline reference, you can purchase Planet Lactose: The Best of the Blog as an ebook on or Almost 100,000 words on LI, allergies, milk products, milk-free products, and the genetics of intolerance, along with large helpings of the weirdness that is the Net.

Tuesday, September 26, 2006

Food Labels Not Understood by the Sick

We've all heard that the poor get sicker than the more well-off, and we've heard that too many people in the country don't understand what good nutrition means.

Now a study done at the Vanderbilt University Medical Center shows that the sicker are also the less-educated.

The study, "Patient Understanding of Food Labels: The Role of Literacy and Numeracy" by Russell L. Rothman, MD MPP, Ryan Housam, BS, Hilary Weiss, BS, Dianne Davis, RD CDE, Rebecca Gregory, MS RD CDE, Tebeb Gebretsadik MPH, Ayumi Shintani, PHD MPH, and Tom A. Elasy, MD MPH, American Journal of Preventive Medicine, Volume 31, Issue 5 (November 2006), and reported at, looked at 200 primary care patients from a "wide socioeconomic range."

Even so, 63% had less than 9th-grade numeracy skills and 23% had less than 9th-grade literacy skills. This was bound to be a problem, since 40% of the study patients "had a chronic illness for which specific dietary intervention is important (e.g., hypertension, diabetes), and 23% reported being on a specific diet plan."

They asked those in the study basic questions about interpreting and understanding nutrition labels, and to do the basic math required to convert a serving size to a whole package.

One part of the NLS [Nutrition Label Survey] asked subjects to interpret food labels, such as determining carbohydrate or caloric content of an amount of food consumed. The other part asked patients to choose which of two foods had more or less of a certain nutrient, giving patients a 50/50 chance to guess the correct food item. Also, half of the survey questions involved products that were clearly labeled on their package as "reduced carb," "low carb," or designed for "a low-carb diet."

Overall, patients correctly answered 69% (SD 21%) of the NLS questions. For example, only 32% of patients could correctly calculate the amount of carbohydrates consumed in a 20-ounce bottle of soda that had 2.5 servings in the bottle. Only 60% of patients could calculate the number of carbohydrates consumed if they ate half a bagel, when the serving size was a whole bagel. Only 22% of patients could determine the amount of net carbohydrates in 2 slices of low-carb bread, and only 23% could determine the amount of net carbohydrates in a serving of low-carb spaghetti. Common reasons for incorrect responses included misapplication of the serving size, confusion by extraneous material on the food label, and incorrect calculations.

The optimists would say there's good news in the finding that "Most patients reported using food labels and found labels easy to understand."

As a pessimist, I say that most is nowhere good enough. The nutrition labels are designed to be as simple as straightforward as possible while still retaining all the important information. They were tested for years before getting the government's OK. If more than three-quarters of a patient population can flunk understanding them, even for one question, then the labels aren't doing their job.

I don't blame the government for this. Schools are the one who are failing. Or have failed, since presumably all of the patients in the study were adults. Basic literacy and basic numeracy are absolute musts for health, for nutrition, for management of disease, and for every other aspect of life.

People have to be able to understand what they eat as well as the medicines they take and the advice doctors give them. If even a small percentage of the population can't do this, we're facing a health crisis. If large numbers of the population, especially the sicker part, can't do this, the crisis is already here.

Bad, bad news, indeed.

Bookmark and Share


daisha said...


Steve Carper said...

If by "it" you mean lactose intolerance, sure. LI is not a disease, it's a collection of symptoms that occur after you eat food that contains the milk sugar lactose. All you have to do is avoid milk products and you won't - can't - have LI symptoms.

Check my web site at for hundreds of dairy-free milk substitutes. also lists huge numbers of these products.

You don't have to go that far. Lactase pills are available everywhere and they do the job of digesting the lactose for you.

Allergies work the same way. Avoid the food that contains the allergen and you won't get the symptoms.