Consumer Research on Nutrition, Diet, and Health
Below are research abstracts of consumer research studies conducted or supported by the Center for Food Safety and Applied Nutrition.
The FDA Health and Diet Survey: A Data Resource
The Health and Diet Survey is a national consumer survey conducted by the Food and Drug Administration (FDA). The national single-stage random-digit-dialing telephone survey has been commissioned by CFSAN since early 1980’s. Respondents are randomly selected non-institutionalized adults in the 50 states and the District of Columbia. The latest iteration was conducted in 2008.
The purpose of the survey is to track and gather information on consumer awareness, attitudes and practices related to health and diet issues. In particular, the survey focuses on foods and dietary supplements, two categories of the consumer products regulated by the FDA. On diet and health, the survey asks about (1) awareness of the relationship between diet and diseases (cancer, heart disease, high blood pressure), (2) knowledge of fats and cholesterol, (3) knowledge of dietary deficiencies, (4) dietary management practices, and (5) use and impact of food labels. On dietary supplements, the survey asks about (1) prevalence of use, (2) information sources and uses, (3) perceptions of dietary supplements and their labels, (4) substitution of dietary supplements for prescription or over-the-counter drugs, (5) adverse experiences with dietary supplements, and (6) children's and teenagers' use of dietary supplements. The available demographic information includes gender, age, education, race/ethnicity, household size, pregnancy/lactation status, health status, region, and household income. [Contact: Serena Lo]
Chung-Tung J. Lin and Steven T. Yen. 2010. Knowledge of Dietary Fats among US Consumers. Journal of the American Dietetic Association 110(4):613-8.
Dietary advice emphasizes that some dietary fats increase the risk of heart disease (HD) while others decrease the risk if they are substituted for risk-increasing fats. Thus, it is important that consumers understand the differences between dietary fats. Existing evidence, however, suggests troublesome consumer misunderstanding. As part of its continuing effort to promote public health, the US Food and Drug Administration measured consumer awareness and understanding of dietary fats in its Health and Diet Survey ─ 2004 Supplement. After cognitive interviews and pretests of the questionnaire, telephone interviews of randomly selected non-institutionalized adults age 18 and above in the US were conducted between October 12, 2004 and January 21, 2005. Using cross-sectional data collected from 1,798 respondents who completed the survey, this study estimated the prevalence of awareness and understanding of six dietary fats among US adults and identified the characteristics of adults with different levels of awareness and understanding. Descriptive analyses were used, along with logistic regression models, developed to accommodate the survey design and responses. There was a wide disparity among US consumers in their awareness and understanding. Saturated fat was most recognized and understood, while awareness of other fats was much lower. Most importantly, having heard of a fat did not necessarily mean understanding its relationship with HD. Only half of those who had heard of trans fat and omega-3 fatty acids understood that the fats raise and lower the risk of HD, respectively. Only a minority of those who had heard of partially hydrogenated oil and polyunsaturated fat knew the fats raise and lower the risk of HD, respectively. Many admitted being uncertain about how a fat relates to the risk of HD. College or more educated adults had better awareness and understanding. Non-white adults were less knowledgeable. Findings on the awareness and understanding and how they are related to individual characteristics can inform deliberations about educational messages, nutrition programs, and food labeling about dietary fats to promote public health. [Contact: Chung-Tung Lin]
Babgaleh B. Timbo, Marianne P. Ross, Patrick V. McCarthy, and Chung-Tung J. Lin. 2006. Dietary Supplements in a National Survey: Prevalence of Use and Reports of Adverse Events. Journal of the American Dietetic Association (106, 12):1966-1974.
The study examined information collected from the 2002 Health and Diet Survey regarding the use dietary supplements and self-reported health problems that the survey participants believed were related to dietary supplements. Survey respondents were queried as to whether or not they had taken a dietary supplement during the past year and if they had experienced any health problem that they attributed to supplement use. The study found that 73 % of US noninstitutionalized adults aged 18 years or older who spoke English and resided in households with telephones used a dietary supplement in the previous 12 months and 4% of them had experienced an adverse event that they believed might be related to dietary supplement use. Eighty-five % of supplement users reported taking multivitamins/multiminerals and 13.3% of adverse events reported were attributed to multivitamins/multiminerals. A higher proportion of supplement users with adverse events than users without adverse events were concurrently taking supplements and prescription drugs or were
taking supplements instead of prescription drug to treat or prevent a health condition. The study suggests that food and nutrition professionals and other health care professionals should take special care to learn about their patients’ use of these products. [Contact: Chung-Tung Lin]
Alan S. Levy, Sara B. Fein, and Marilyn Stephenson. 1993. Nutrition Knowledge Levels about Dietary Fats and Cholesterol: 1983-1988. Journal of Nutrition Education 25(1): 60-66.
Consumer knowledge of dietary fats and cholesterol was analyzed for trends over time and for relationships with demographic characteristics and health and dieting behaviors. The data were obtained from three approximately biennial Health and Diet Surveys conducted by the Food and Drug Administration and the National Heart, Lung and Blood Institute between 1983 and 1988. Statistical methods included regression analysis and factor analysis. The results indicate that consumer knowledge about dietary fats and cholesterol is poor. Respondents with greater knowledge in 1988 were those who were more educated, middle-aged, or white, and those who were on a cholesterol-lowering diet. The regression analysis of 1988 scores indicated that education was the most important predictor of knowledge scores. Being on a self-prescribed cholesterol-lowering diet was related to higher knowledge, but being on a physician-recommended diet was related to higher knowledge scores only for younger respondents. None of the health behaviors, except engaging in regular exercise, was associated with higher knowledge levels. [Contact: Alan Levy]
Food Labeling, Nutrition, and Health
Judy Labiner-Wolfe, Chung-Tung J. Lin, and Linda Verrill. 2010. Effect of Low-Carbohydrate Claims on Consumer Perceptions about Food Products’ Healthfulness and Helpfulness for Weight Management. Journal of Nutrition Education and Behavior 42(5):315-320.
The online experimental study was designed to evaluate effect of low-carbohydrate claims on consumer perceptions about food products' healthfulness and helpfulness for weight management. A total of 4,320 members of a national online consumer panel were randomly assigned 1 of 12 front-of-package claim conditions on bread or a frozen dinner. Seven of the 12 conditions also included Nutrition Facts (NF) information. They were asked to rate, on Likert scales, perceived healthfulness, helpfulness for weight management, and caloric content of products. Participants who saw front-of-package-only conditions rated products bearing low-carbohydrate claims as more helpful for weight management and lower in calories than the same products without a claim. Those who saw the bread with low-carbohydrate claims also rated it as more healthful than those who saw no claim. When the NF label was available and products had the same nutrition profile, participants rated products with low-carbohydrate claims the same as those with no claim. In conclusion, consumers who do not use the NF panel may interpret low-carbohydrate claims to have meaning beyond the scope of the claim itself. [Contact: Chung-Tung Lin]
Linda Verrill and Conrad J. Choiniere, 2009. Are Food Allergen Advisory Statements Really Warnings? Variation in Consumer Preferences and Consumption Decisions. Journal of Food Products Marketing. 15:139–151.
The authors surveyed consumers for preferences on allergen advisory statements on food labels (N = 1,243). They also conducted an experiment to assess how consumers use advisory statements (N = 4,049) to make food consumption decisions. Results show that food allergic individuals, including caregivers to food allergic individuals, and a control group of nonallergic people preferred “Allergen Information: May Contain . . .” over three other statements tested. The experiment revealed measurable differences among the statements in how they are used to make food consumption decisions. Statements rated as more believable and more helpful also received higher ratings on a “likelihood of eating/ serving” measure. [Contact: Linda Verrill]
Chung-Tung J. Lin. 2008. How Do Consumers Interpret Health Messages on Food Labels? Nutrition Today 43(6): 267-272.
How do consumers interpret labeling statements claiming nutritional or health benefits of a food product? What impacts do these statements have on how consumers make shopping decisions? These are important questions for regulators, the industry, and nutrition educators and professionals in communicating with consumers about food labels and dietary choices. To help provide consumers more and better information about foods, the U.S. Food and Drug Administration conducted an Internet study, from January to March, 2006, to understand causal relationships between health claims and other health messages and consumer responses. The study suggests that consumers have different levels of familiarity with different nutrients and diet-disease relationships. Both consumer familiarity with a nutrient or diet-disease relationship and the type of health message can affect consumer interpretation of health messages and their perceptions of products. More detailed health messages appear to have stronger impacts on consumers when the nutrients or diet-disease links are less familiar or unknown. [Contact: Chung-Tung Lin]
Amy M. Lando and Judy Labiner-Wolfe. 2007. Helping consumers make more healthful food choices: consumer views on modifying food labels and providing point-of-purchase nutrition information at quick-service restaurants. Journal of Nutrition Education and Behavior 39(3):157-63.
Sixty-eight consumers in four US cities participated in eight focus groups to discuss their (1) interest in nutrition information on food labels and quick-service restaurant menu boards, and (2) reactions to modifying this information to help highlight calories and more healthful choices. They expressed views on alternative presentations of nutrition information on packaged food items and quick-service restaurant menu boards. The study found that participants (1) were interested in having nutrition information available, but would not use it at every eating occasion; (2) thought that food products typically consumed at 1 eating occasion should be labeled as a single serving; and (3) indicated that an icon on labels and menu boards that signaled more healthful options could be helpful. Findings provided a basis for the development of more systematic studies to better understand whether alternative presentations of nutrition information would help consumers. [Contact: Amy Lando]
Chung-Tung J. Lin, and Jonq-Ying Lee. 2004. Who Use Food Label Information: A Case Study of Dietary Fat. Journal of Food Products Marketing 10(4): 7-37.
This study extends previous research by using a simultaneous-equation model to measure the relationship between fat intake and label use. Using the 1994-6 USDA Continuing Survey of Food Intakes by Individual and Diet and Health Knowledge Survey data, our results suggest individuals who consume a higher percentage of calories from fat are less likely to report searching for fat information on food labels. We also identified the roles played by several psychological variables on information search and fat intake. These findings have important implications on nutrition education and effectiveness of food labels. [Contact: Chung-Tung Lin]
Chung-Tung J. Lin, Jonq-Ying Lee, and Steven T. Yen. 2004. Do Dietary Intakes Affect Search for Nutrient Information on Food Labels? Social Science & Medicine 59(9):1955-1967.
This study explores the association between dietary intakes of these three nutrients and psychological or demographic factors and the search for total fat, saturated fat, and cholesterol
information on food labels. Psychology literature suggests a negative association between intakes of these nutrients and probability of search for their information on food labels. Health behavior theories also suggest perceived benefits and costs of using labels and perceived capability of using labels are associated with the search behavior. We estimate the relationship between label information search and its predictors using logistic regressions. Our samples came from the 1994–1996 Continuing Survey of Food Intakes by Individuals and Diet and Health Knowledge Survey conducted by the United States Department of Agriculture. Results suggest that search for total fat, saturated fat, and cholesterol information on food labels is less likely among individuals who consume more of the three nutrients, respectively. The search is also related to perceived benefits and costs of using the label, perceived capability of using the label, knowledge of nutrition and fats, perceived efficacy of diets in reducing the risk of illnesses, perceived importance of nutrition in food shopping, perceived importance of a healthy diet, and awareness of linkage between excessive consumption of the nutrients and health problems. These findings suggest encouraging search of food label information among consumers with unhealthy dietary habits would need innovative approaches. Yet, nutrition education can be instrumental in
encouraging this search by stimulating motivation and providing technical help. [Contact: Chung-Tung Lin]
Alan S. Levy and Sara B Fein. 1998. Consumers' Ability to Perform Tasks Using Nutrition Labels. Journal of Nutrition Education 30(4):210-217
Consumers' ability to perform common nutritional label use task components, which revealed the effect of prior knowledge, were analyzed for relationships with demographic characteristics, label reading, and health status. Data were from a mall intercept experimental study. Most consumers (78%) accurately compared two products, 58% accurately evaluated nutrient level claims, 45% comprehensively balanced nutrients over a daily diet, and 20% accurately calculated the contribution of a single food to a daily diet, a task that required complex math. The subjects who performed significantly poorer were over 55 years of age, nonwhite, and less educated than those who performed best. Not reading food labels and having a diet-related health condition were also related to poorer performance. Task component analysis showed that all types of subjects shared the same response tendencies when making nutrition judgments. The findings suggest that dietary guidance for consumers will be more effective if it does not require quantitative tasks but relies instead on tasks that are easier for consumers. [Contact: Alan Levy]
Mario F. Teisl and Alan S. Levy. 1997. Does Nutrition Labeling Lead to Healthier Eating? . Journal of Food Distribution Research. 3(28):19-26
Nutrient labeling is found to significantly affect consumer purchase behavior; some evidence that consumers may act as if they hold nutrient (or health risk) budgets is found. Providing nutrient information may allow consumers to more easily switch consumption away from 'unhealthy' products in those food categories where differences in other quality characteristics (e.g., taste) are relatively small between the more and less 'healthy' products, toward 'unhealthy' products in categories where differences may be relatively large (i.e., a 'substitution effect'). If this substitution effect is large, nutrient labeling may not change the overall consumption of 'unhealthy' nutrients and thus may not lead to significant changes in health risk. [Contact: Alan Levy]
Alan S. Levy, Sara B. Fein, and Raymond E. Schucker. 1996. Performance Characteristics of Seven Nutrition Label Formats. Journal of Public Policy and Marketing 15(1):1-15.
The authors evaluate seven nutrition label formats to determine consumer comprehension and acceptance of displayed information. They test comprehension of five tasks: comparing two products, judging healthfulness, verifying claims, estimating servings needed to meet the daily requirements for a nutrient, and balancing nutrients in a daily diet. Performance scores were higher on some tasks--particularly dietary management ones--for formats that displayed nutrient amounts in percentages than for those that displayed nutrient amounts in metric units, even when interpretational aids were included on the metric formats. The two most preferred formats were metric formats with an interpretational aid. The findings have an important impact on decisionsabout the final nutrition label format required by the Food and Drug Administration. [Contact: Alan Levy]
Christine J. Lewis and Elizabeth A. Yetley. 1992. Focus Group Sessions on Formats on Nutrition Labels. Journal of the American Dietetic Association 92(1):62-66
Four consumer focus group sessions, with a total of 40 participants, were conducted to gather information on the utility and appropriateness of selected components of nutrition label formats.. The formats reviewed were bar graphs, pie charts, numeric listings, and adjectival descriptors such as high and low. Participants were asked to compare food labels using various format types and to discuss the utility and interpretability of the formats. The outcomes suggested that these consumers did not find pie charts useful. They considered bar graphs confusing or unnecessary when numeric values were provided. Participants expressed concern that adjectival descriptors could be misleading. The numeric listing format they considered the most useful consisted of two columns of numbers: one listing the amounts of food components present in a serving of the food, and a second listing either the percentage of the label reference value (e.g., the US Recommended Daily Allowance) or the quantity established as the label reference value. Participants repeatedly stressed their interest in a simple label. The results form one component of the Food and Drug Administration's efforts to evaluate nutrition label formats and will be used in conjunction with ongoing experimental and quantitative research studies. [Contact: Linda Verrill]
Alan S. Levy, Sara B. Fein, Raymond E. Schucker. 1992. More Effective Nutrition Label Formats Are Not Necessarily Preferred. Journal of American Dietetic Association 92(10):1230-1234.
An experimental design was used to compare performance and preference for five nutrition label formats. Four performance measures--accuracy and false-positives in identifying nutrient differences, time required, and correctness in judging which product was more nutritious-- were derived from a product-comparison task. A sample of 1,460 food shoppers over 18 years old was recruited by a shopping mall-intercept method. Results of the study demonnstrated that preferences and performance do not necessarily agree. The Control format, which had no nutrition profile information, performed the best but was liked the least. The Adjectival format, which provided nutrition profile information in the form of descriptive adjectives, was the most preferred. Results also showed that listing Daily Reference Values or nutrition profile aids increased preference but either did not affect performance or decreased it, depending on the specific aid and performance measure. Formats that some subjects liked for having adequate information others disliked for being hard to use. Formats that some subjects liked for being easy to use others disliked for having inadequate information. Age, education, and race were related to all of the performance measures except judgment of relative nutrition. Only gender was related to preference. Results of the study are useful as guidance for the development of consumer education materials. [Contact: Alan Levy]
Alan S. Levy, Raymond E. Schucker, Janet E. Tenney, and Odonna Mathews. 1988. Consumer Demand for Detailed Nutrition Information: A Case Study. Journal of Nutrition Education 20(4):161-166.
We monitored sales of a nutrition information booklet in 25 Baltimore, Maryland, and 85 Washington, DC, supermarkets for 72 weeks. The Giant Food Inc. supermarket chain introduced the booklet titled "Special Diet Alert Guide" in conjunction with the Special Diet Alert shelf label nutrition information program. We estimated that 9 to 10% of Baltimore households and 7% of Washington households that patronized Giant stores purchased a Special Diet Alert Guide at some point during this period. Much of the demand occurred in the first 12 weeks. Promotional advertising of the program had a positive impact on booklet sales, but the effect was significantly larger in Baltimore stores. The generally higher level of interest in the guides observed among Baltimore shoppers compared to Washington shoppers is discussed in terms of the previous experience that Washington shoppers had with an earlier version of the guide. [Contact: Alan Levy]
James T. Heimbach. Risk Avoidance in Consumer Approaches to Diet and Health. 1987. Clinical Nutrition 6(4):159-162.
Advice to the public to avoid or limit various food components has come from all sources, with all levels of scientific support. Therefore, a major task facing the nutrition education community to reacquaint the public with the idea that food choice can be based not only on avoidance but also on a search for positive nutritional value. This is not to say that concern with over- consumption of various food components will or should disappear, but it is possible that a more even-handed evaluation of risk and benefits from food could replace the one-sided concern with risk avoidance that currently dominates the public's approach to diet and health. [Contact: Linda Verrill]
Alan S. Levy and Raymond C. Stokes. 1987. Effects of a Health Promotion Advertising Campaign on Sales of Ready-to-Eat Cereals. Public Health Reports 102(4):398-403.
The objective of this study was to determine how the sales of various segments of the high fiber and non-high fiber, ready-to-eat (RTE) cereal market were influenced by a health message advertising campaign about the possible benefits of a high fiber, low fat diet for preventing some types of cancer. The fiber statements in the media campaign were endorsed by the National Cancer Institute (NCI). The campaign was undertaken by the Kellogg Company to promote its line of high fiber cereal-products, including Kellogg's All-Bran . The data base consisted of computerized purchase data from 209 Giant Food, Inc. supermarkets in the Baltimore, MD, and Washington, DC, metropolitan areas. All the RTE cereals products in the stores were classified according to their fiber content and competitive market positions compared with Kellogg high fiber cereals. Estimates of market share for the various classes of RTE cereal products were obtained weekly for each store during a period of 64 weeks, beginning 16 weeks before the start of the campaign. Shifts in market share between high fiber and non-high fiber cereal classifications indicate substantial increases in consumer purchases of Kellogg high fiber cereals, particularly All-Bran, beginning with the start of the Kellogg advertising campaign. Growth in market share of high fiber cereals continued during the entire 48-week evaluation period, with much of the later growth in non-Kellogg high fiber cereals. Growth in sales of high fiber cereals was mainly at the expense of low fiber cereals such as a granola-type products. The implications of these results for the competitive and educational effectiveness of commercially sponsored health and diet messages are discussed. [Contact: Alan Levy]
Alan S. Levy, Odonna Mathews, Marilyn Stephenson, Janet E. Tenney and Raymond E. Schucker. 1985. The Impact of a Nutrition Information Program on Food Purchases. Journal of Public Policy and Marketing 4(1):1-13.
A quasi-experimental repeated measures design using a matched set of 20 test and comparison supermarkets in the Washington, D.C. and Baltimore, Md., metropolitan areas was used to evaluate a nutrition information program called "Special Diet Alert" (SDA) introduced by Giant Food, Inc. into Washington, D.C. stores in March 1981. The objective of the SDA program was to help supermarket shoppers find products for special diet needs by providing brand-specific (i.e., individual product level) shelf markers that identified products considered low or reduced in sodium, calories, cholesterol, and fat, supplemented by take-away information booklets available from a rack in the store which listed SDA brand names and specific nutrient values. Market shares of these products were tracked over the two-year evaluation period in Washington, D.C. and Baltimore stores. The pattern of differential sales trends across 16 individual food categories was complicated, but sales of shelf-marked products increased on the average 4 to 8 percent more over the two-year evaluation period in Washington, D.C. than in Baltimore, Md. stores. The average magnitude of effect attributable to SDA was modest in comparison with other factors influencing consumer purchases, highlighting the need for powerful evaluation designs to assess the effectiveness of information programs that operate in the context of many other more powerful influences. Further research is needed to determine which aspects of the SDA program were critical to its success, but one obvious difference between SDA and other in-store nutrition information programs that have been reported in the literature was the use of individual brand-specific shelf markers to deliver nutrition information to shoppers rather than prominently displayed sectional posters and detailed educational pamphlets. [Contact: Alan Levy]
Robert G. Orwin, Raymond E. Schucker, and Raymond C. Stokes. 1984. Evaluating the Life Cycle of a Product Warning: Saccharin and Diet Soft Drinks. Journal of Evaluation Review 8(6):801-822.
The effect of the saccharin warning label on sales of diet soft drinks was modeled with an autoregressive integrated moving average (ARIMA) process. Retail price trends and attendant publicity were modeled concurrently to separate these effects from those due to the warning. Results indicated that the label produced a small yet statistically significant reduction in sales, with an abrupt onset and, thus far, permanent duration. Reasons for the absence of decay effects, limitations of interpretability, and ideas for improving future evaluations of warning labels are discussed. [Contact: Linda Verrill]
James T. Heimbach and Raymond C. Stokes. 1982. Nutrition Labeling and Public Health: Survey of American Institute of Nutrition Members, Food Industry, and Consumers. American Journal of Clinical Nutrition 36:700-708.
Five hundred thirty-one members of the American Institute of Nutrition, 177 persons from the food industry, and 107 consumers from a Food and Drug Administration mailing list responded to a survey dealing with nutrition labeling of foods. They identified obesity and heart disease as the major diet-related national health problems and chose information about calories, sodium, fat, protein, iron, calcium, and carbohydrates as most useful to the public. [Contact: Linda Verrill]