LITERATURE SEARCH STRATEGY

In order to review the most relevant scientific literature available, study staff initially searched a range of online bibliographic databases, including ABI/INFORM, Academic Search Premier, AGRICOLA, ASAPII, EMBASE, New York Academy of Medicine’s Grey Literature Collection, NTIS government documents, PsychINFO, PubMed/ MEDLINE, Science Direct, Web of Science, and WorldCat/First Search. To identify primary literature, staff first conducted general searches on topics relevant to assessment of consumer information processing, use, and understanding of FOP systems and symbols, as well as advertising, marketing, and merchandising of food products. Using the results of the primary search, staff developed key search terms and then conducted secondary searches. They chose search terms based on relevance to the study objectives and topic areas identified by the committee. Searches were limited to English language publications. After the initial search, staff designed a comprehensive search strategy in consultation with librarians at the George E. Brown Jr. Library of the National Academies. Search terms incorporated relevant MeSH (Medical Subject Headings) terms as well as terms from the EMBASE thesaurus. Table D-1 provides an example of how searches were conducted; only a subset of terms from the overall search are shown because inclusion of the entire search in the report was not practical.

TABLE D-1 Example of Searches Using Key Words to Identify Relevant Literature

Staff limited the searches to English language and to publication dates of 2000 and later. The initial search retrieved more than 4,900 citations, including more than 1,000 business citations, which were then sorted into predefined topics identified by the committee. The topical search terms included

•   Advertising/marketing

•   Brand names

•   Brand preferences

•   Choice behavior

•   Clutter

•   Consumer behavior

•   Diet/nutrient intake

•   Education

•   Food choice

•   Food law and legislation

•   Health promotion

•   Health/food beliefs

•   Health/safety

•   Literacy/numeracy

•   Low income/poverty

•   Nutrition labeling information

•   Purchase intention

•   Reformulation

•   Retail/purchasing

•   Socioeconomics

Relevant references obtained from the initial search were then screened and categorized according to the research taxonomy shown in Box D-1, and then annotated by staff. The committee was provided reference lists of key citations in tabulated format for evaluation and rating.

EVIDENCE RATING

Studies were segregated by design into the first level of the literature review and evaluation process as follows:

•   Experimental studies, including randomized controlled trials, field experiments, online or lab experiments

•   Descriptive/observational studies, including cohort, cross-sectional, and ecological designs

•   Reviews

The committee rated experimental studies, including field, laboratory, and online experiments as the strongest type of evidence, but also considered observational and descriptive research. To evaluate this type of evidence, the committee considered the quality of the research design as well as whether the evidence was supportive of any experimental research. Reviews were included but not rated. To evaluate the literature for further consideration and inclusion in the report, the committee assessed the evidence according to the following factors:

•   Inclusion criteria, based on methodological approach, including adequate control group, blinding or no blinding, appropriate statistics

 ο I—Inclusion criteria are reasonable and appropriate

 ο II—Some criteria missing or not adequate

 ο III—Inclusion criteria absent or not satisfactory

•   Generalizability of the study/Population demographics

 ο I—Sample is representative of the target population. Sufficiently large to cover both sexes, wide age range, and other important feature of the target populations (e.g., diet)

 ο II—Sample is representative of a relevant subgroup of the target population, but not the entire population

 ο III—Sample is representative of a narrow subgroup of subjects only, and is of limited applicability to other subgroups

•   Food product category

 ο I—3 or more products

 ο II—2 or fewer products

 ο III—No products in the study

Staff maintained and posted on the committee’s portal a reference database of the evaluated evidence. The database was searchable by keywords, annotations, or other criteria. Bibliographies were updated throughout the study and as committee members requested journal articles and other resources.

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Appendix E

Evaluation of Nutrient Content of Selected Example Foods

¹ used by the committee to assess strengths and limitations of and regulatory issues associated with nutritional criteria for an FOP symbol system based on current regulations for nutrition and ingredient labeling and nutrient content and health claims.

² and the USDA Food and Nutrient Database for Dietary Studies, 3.0. Each product is only one of many examples of products within a category and may not be representative of all products in its category. The items are organized by Food and Drug Administration (FDA) product categories for individual foods, then by lowest to highest reference amounts customarily consumed (RACC) within a category.³

Table E-2 displays the FOP points earned by the product examples based on the following two-step approach for evaluation:

Step 1: Determine whether a product should not earn any FOP points for saturated and trans fats, sodium, or added sugars based on eligibility criteria because the product contains an amount of one or more of the stated nutrient components that is not consistent with the Dietary Guidelines.

Step 2: Determine whether a product that meets the eligibility criteria earns FOP points for saturated and trans fats, sodium, and/or added sugars based on qualifying criteria that assess acceptable amounts.

The first step excludes a food or beverage from earning FOP points for saturated and trans fats, sodium, and added sugars because the amount of any one of these components is considered “too high.” For example, a product “high” in sodium but containing no or low levels of saturated fat, trans fat, and added sugars would not be viewed as consistent with the Dietary Guidelines. Such a product should be excluded from earning FOP points for saturated and trans fats and added sugars even if the amounts of these nutrient components otherwise meet qualifying criteria. In the second step, a food or beverage that meets the eligibility criteria can then be evaluated

¹ It is Institute of Medicine (IOM) policy to not use brand names of products.

² Available online: http://www.peapod.com/ (accessed on various dates throughout 2010 and 2011).

³ Food product categories as identified in 21 CFR 170.3.