Newswise — In one of the most rigorous studies ever conducted to determine how well people comprehend the information provided on food nutrition labels, researchers have found that the reading and math skills of a significant number of people may not be sufficient to extract the needed information, according to an article published in the November issue of the American Journal of Preventive Medicine.
Using standardized and validated tests for literacy (REALM -Rapid Estimate of Adult Literacy in Medicine) and numeracy (WRAT3 - Wide Range Achievement Test), researchers from Vanderbilt University Medical Center surveyed 200 primary care patients from a wide socioeconomic range. A Nutrition Label Survey (NLS), designed with input from registered dietitians, primary care providers, and experts in health literacy/numeracy to evaluate patient understanding of current nutrition labels, was used to measure comprehension of current food nutrition labels. One part of the NLS 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."
Sixty-eight percent of patients had at least some college education, and 77% had at least 9th-grade level literacy skills. However, 63% of patients had less than 9th-grade numeracy skills. Over 40% had a chronic illness for which specific dietary intervention is important (e.g., hypertension, diabetes), and 23% reported being on a specific diet plan. Most patients reported using food labels and found labels easy to understand.
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.
According to Russell L. Rothman, MD MPP, "The study showed that many patients struggle to understand current food labels, and that this can be particularly challenging for patients with poor literacy and numeracy (math) skills. Poor understanding of nutrition labels can make it difficult for patients to follow a good diet. Of particular concern are situations that involve interpretation and application of serving size. There are many opportunities for health care providers to improve how they talk to patients about using food labels and following diets. There are also opportunities for the FDA to improve how food labels are designed in order to improve how patients take care of their nutrition.
The article is "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.
The article appears in the American Journal of Preventive Medicine, Volume 31, Issue 5 (November 2006) published by Elsevier.
Full text of the article is available upon request.
ABOUT RUSSELL ROTHMAN, MD, M.P.P.Assistant Professor, Internal Medicine and Pediatrics, Vanderbilt Center for Health Services Research
Dr. Rothman received his bachelor's degree in Zoology and Political Science from Duke University in 1992. He received his MD from Duke in 1996. During this time he also completed a master's in Public Policy (M.P.P) at the Sanford Institute of Public Policy at Duke. After this, Dr. Rothman remained at Duke where he completed a Med-Peds residency in 2000. From 2000 to 2002, he served as a Robert Wood Johnson Clinical Scholar at the University of North Carolina in Chapel Hill. During this time, he was a Clinical Instructor in Internal Medicine and Pediatrics, and he performed health services research on clinical issues that span pediatric and adult medicine. In 2002, he joined the faculty at Vanderbilt as an Assistant Professor in the Vanderbilt Center for Health Services Research, and the Med-Peds program. Dr. Rothman's current research focuses on improving care for adult and pediatric patients with chronic disease. He is involved with the Med-Peds residents both for clinical and research related training.
ABOUT THE AMERICAN JOURNAL OF PREVENTIVE MEDICINE
The American Journal of Preventive Medicine (http://www.ajpm-online.net) is the official journal of The American College of Preventive Medicine (http://www.acpm.org) and the Association for Prevention Teaching and Research (http://www.atpm.org). It publishes articles in the areas of prevention research, teaching, practice and policy. Original research is published on interventions aimed at the prevention of chronic and acute disease and the promotion of individual and community health. The journal features papers that address the primary and secondary prevention of important clinical, behavioral and public health issues such as injury and violence, infectious disease, women's health, smoking, sedentary behaviors and physical activity, nutrition, diabetes, obesity, and alcohol and drug abuse. Papers also address educational initiatives aimed at improving the ability of health professionals to provide effective clinical prevention and public health services. The journal also publishes official policy statements from the two co-sponsoring organizations, health services research pertinent to prevention and public health, review articles, media reviews, and editorials.
The American Journal of Preventive Medicine is ranked 14th out of 99 Public, Environmental & Occupational Health titles and 16th out of 105 General and Internal Medicine titles according to the Thomson Scientific Institute for Scientific Information's 2005 Journal Citation Reports.