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7 RATIONALE AND RECOMMENDATIONS FOR LONGER-TERM rMPLEMENTATION Some Committee recommendations of importance to data users are appropriate for implementation over a longer term than those in Chapter 6. These recom- mendations are discussed in this chapter. The Committee acknowledges that implementation of these recommendations will require time, money, and research. However, it urges that each of the recommendations found in this chapter be given full consideration. Like the recommendations in Chapter 6, the recommendations in this chapter have been developed as a result of the Committee's information-gathering processes and reflect an ef fort to respond to the needs identif fed by survey data users. The recommendations in this chapter are related primarily to modifications in food intake methods to include more detailed information in the survey data bases, modifications in food intake information to expand and improve data bases on the composition of foots, and the handing of the data themselves. SURVEY PURPOSES AS GUIDES This report has previously referred to the importance of considering modifications of the surveys in the context of their separate purposes. The purposes of the surveys serve as useful guides for identifying the agencies most likely to be involved in undertaking the Committee's recommended activ- ities or those most likely to serve as lead agencies if the Committee's recom- mentations involve more than one agency or organization. Indeed, the Com- mittee has uset the separate survey purposes as guides in developing some of its reco~entat ions . The Committee has developed recommendations both in relation to the separate core survey purposes and from its perspective of the conjoint use of the survey data bases in a system of nationwide food and nutrition monitoring (see Chapter 5~. The recommendations in this chapter provide an opportunity to consider the broadening of future uses of the separate core survey data base.. FOOD INTAKE METHODS Data users have identified several needs relates directly to food intake methods. The Committee appreciates the importance of USDA's continuing pro- gram of intramural and extramural research on food intake methods and comments that effort.
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- 88 - Given the primary purposes of the NFCS ant its importance in the broad array of questions that must be addressed through nationwide foot and nutrition monitoring, the Committee recommends a continuing commitment to that research program. The Committee also recommends that DHHS adopt a similar program of intramural and extramural research on methods, some of which could be jointly undertaken with USDA. Several of the recommendations fount in this chapter depend on the results of research projects in progress. Others may require additional limited research. Still others are likely to involve agency commitments of research or personnel resources. The Committee regards these research commitments an necessary, feasible, and cost-effective. CONTINUED STUDY OF SURVEY METHODS In citing the importance of replicated observations of 1-day intakes (Chapter 6), the Committee envisions the use of these data to derive estimates of the dis tribution of "usual" intakes among individuals . In turn, such dis- tributions would be used to consider the prevalence of high-risk intakes, whether such a risk is represented by low or high intake. The Committee recognizes that for this purpose, where data are analyzed by appropriate statistical techniques, in the longer term it may not be necessary to continue to obtain 3 data-days of intake of all survey subjects. However, such a longer-term design question must be addressed from the background of the analysis of existing shorter-term data sets and, possibly, special data collections. The Committee strongly recommends that USDA continue its investigations of survey methods. It suggests that USDA, with the appropriate statistical resources, then examine the design requirements of tietary-data collection for proposed approaches to tata analysis ant interpretation. Other complementary approaches address the question of systematic under- estimation of dietary intake. In earlier recommendations, the Committee addressed some aspects of this concern regarding improving information on the intake of dietary supplements (underestimation of essential nutrient intake) ant discretionary food components (underestimation of energy and nutrient intake). In addition, physiologic studies to validate intake methods, espe- cially total energy intake, may be needed. The Committee recommends that the agencies form a joint working group to evaluate newer methods for validating energy intake and expenditure es timates .
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- 89 The goal of the evaluation should be to identify systematic error in estimating dietary intake of energy and determine the bese method for correction. USE OF UNIVERSAL PR~IICT CODES Inadequate and inconsistent descriptions of food products create problems in food coding and the estimation of the nutrient content of foods. One pos- sible way of reducing this problem would be to make use of the universal product codes (UPCs) that now appear on nearly all canned and packaged food products and even on some fresh items that are repackaged in ~ tores 7. The use of these codes permits automation in recording packaged foods (for instance in home interviewa). It remains to be determined whether the system of UPCs can become an effective part of the data collection process. However, the nature of the codes (their universality), the potential ease of obtaining information from their use, and the precision (specificity) of their description of foods suggest both their utility and the potential ease of incorporating them into the survey coding process. The Committee suggests that, to respond to user needs for greater specificity in food descriptors, consideration be given to the use of UPCs in developing standardized food codes for the food consumption and dietary intake surveys. The Committee also recommends that, if automated data collection applications of UPCe are shown to be feasible, such automation be incorporated into the survey data collection methods. INFORMAT ION ON MEDICAT IONS Many prescription and over-the-counter (OTC) medications can affect food consumption, dietary intake, or nutritional 8 tatus . Patients taking some medications may be advises to avoid particular foods or classes of foods when there is come likelihood of a food~drug interaction. Some medicines interfere with the absorption and use of nutrients. Other medications may substantially increase a sub ject's total dietary exposure to a particular nutrient or other foot component. Still other medications can affect the qualitative and quan- titative data on biochemical indexes of nutritional status. Thus, qualitative and quantitative information on meticatione unset by survey subjects can be important in interpreting the qualitative and quantitative nature of the data reported in the survey data bases. The data bases on dietary intake in each of the separate core surveys should contain more detailed qualitative and quantitative information on
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- so medications being consumed by survey subjects, especially medications affecting nutritional status. Interagency efforts, perhaps through a joint working group, should be used to define the nature and extent of the information to be contained in each o f the survey data bases ant to design questions for the separate surveys. On the basis of the survey purposes, the Committee suggests that 1)HHS serve as the feat agency in this effort. The Committee further recommends that this process be sustained to foster the continuing incorporation of information as new needs emerge. BRAND-NAME INFORMAT ION Some data users expressed a need for more product brand-name identi fi- cation of food items reportedly consumed by survey subjects. Users noted that incorporation of such information into the survey data base tapes would foster wider and easier use of the survey data. However, consumer use of specific brand-name items can vary, e.g., with price and availability. In addition, product label information, if uset for nutrient-dependent questions, may not accurately reflect the amounts of the nutrients consumed. Moreover, information on brand-name products may be even less reliable when gathered outside the home setting, because such information cannot be verified. The latter circumstance is lees likely to have a major design implication for the NFCS, because the NFCS is conducted entirely in respondents ' homes. However, for the NHANES, with it. dietary interviews conducted in mobile exams ination vans, the validity and ret lab ility of brand-name information that is collected may be questionable. There may be major design implications for the NHANES, if its dietary interviews were moves deco the household setting solely to facilitate the verifiable collection of brand-name information related to foot consumption ant dietary intake. A further consideration in the incorporation of product brand-name infor- mation into the survey data bases is related to the degree of specificity that would be imposed on data collection in large national surveys. Under what circumstances does the imposition of such specificity on large national surveys become inappropriate, and when are smaller, specialized surveys more appropr late ? The Committee recommends deferring specific modifications designed to increase collection of product brand-name information in national surveys on food consumption and dietary intake until information on the utility of UPCs or other automa~ced systems for collecting such data can be analyzed. The Committee
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- 91 - recognizes the needs of some usere for this kint of information. However, it is concerned that immediate modification of food intake methods to collect such data before itch validity, reliability, and utility in reporting food consumption and dietary intake are demonstrated may be premature. INFORMATION ON IMPEI)IMENTS 'to FOOD - INTAKE Various characteristics of survey subjects (e.g., food intolerances ) and their environments (e.g., means of transportation) can seriously affect their food choices and dietary patterns; those choices and patterns affect food consumption and dietary intake. Individual characteristics and environmental factors (including income) can be major determinants of food choices. rently, impetimente to and determinants of food choices are not easily com- parable or identifiable across the survey data bares. Such food-selection factors can also be important in the selection, design, implementation, and monitoring of food and from highly selective public education programs to vention programs. Impediments to and determinants Cur- nutrition programs ranging broader national inter- of food selection are thus impor tent to both the independent ant the con joint us es of the core survey data banes. The Committee Bugged to that the separate survey data bases contain some minimum of identical information on determinants of food intake. The Committee further sugges to that the nature and extent of the core questions be determined and developed by a joint interagency working group in a manner similar to that sugges ted for the addition of information on the use of medications by Survey subjects. Many of these determinants may be more closely relates to health Status than to foot intake. For this reason and with the survey purposes as guides, the Committee sugges ts that DHHS serve as the lead agency in this effort. IMPROVEMENTS IN INFORMATION ON COMPOSITION OF FOODS , Some Committee recommendations in Chapter 6 included ~ tandardization and prompt expansion of the data bases on the composition of foods. Effective longer-term improvements in information on the compost ition of foods are also needed. Implementation of some of these longer-term improvements depends on research in analytic methods, and implementation of others depends on the come mitment of research resources.
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- 92 Recommendations in this section are related to research on analytic methods ant to expansion of the Fate on nonnutritive foot components, foot ingredients, and inadvertent components of foods. These recommendations were designed to respond ~ in a continuing, feasible, and cost-effective manner -- to users' needs for more complete and more detailed data on what is being consumed. RESEARCH ON ANALYTIC METHODS FOR NUTRIENT DESTINATION Several assessments of analytic methods used for the quantitative deter- mination of nutrients present in foods have been reported. A recent assesement38 is summarized in Tab le 7-l and illus theater that analytic methods for a number of nutrients are not considered "adequate" for deter- mining the content in foods . This Rugged to that currently availab le quanti- tative information on these nutrients may be of questionable reliability. In the view of the Committee, a priority goal of federally supported research should be improvement in the analytic methods needed to develop public data on the composition of Foote. With the survey purposes as guides, the Committee recommends that USDA serve as the lead agency in efforts to expand and improve qualitative and quantitative data on the composition 0 f foods . The Committee sugges ts that a review of the s Lance of analytic methods will be required to develop a more complete data base on the composition of foods. The Committee recommends that research resources be provided, where necessary, to develop the appropr late ant validated analytic methods needed. The development of methods is particularly important for foot components about whose dietary intake in the United States, whether high or low, there is scienti fic concern . The Committee believes that a broat-based effort for the development 0 f these methods is needed and sugges ts that further programs for their development use the resources of academia, government, and industry. USDA and DENS, perhaps by establishing an interagency working group, should address the need for written criteria (e.g., both minimal standards and adequate standarda) for the analytic methods used in qualitative and quantitative assessments of the composition of foods, evaluation of current methods for food analyses, and strategies for establishing acceptable assay techniques for the chemical analys is 0 f foods .
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— 93 — In the view of the Committee, it is important ensure consistency, comparability, precision, and reliability in analytic meehode and in the dissemination of information about both methods and the determinations that result. The Corm ittee suggests inclusion of representatives of both the National Bureau of Standards and such appropriate scientific organizations as the American Chemical Society, the American Society of Testing Methods, ant the Association of Official Analytical Chemists in efforts undertaken to improve the analytic methods needed to expand ~ tandartized pub kc data on the compos it ion o f foods . DATA ON NONNUTRITIVE FOOD COMPONENTS Data from food consumption surveys have many current and emerging epidemi- ologic applications. Some uses are baset on hypotheses that the intake of food components, either singly or in combination, can be or is (directly or indirectly) related to the cause or aggravation of human diseases. These disease-related hypotheses are often linked to the ingestion of nonnutritive foot components. An obvious example is the concern about dietary exposure to and ingestion of nonnutritive presumptive human carcinogens in the food supply. Naturally occurring nonnutritive substances of plant and animal origin have been shown to have detrimental effects -- examples are enzyme inhibitors, goitrogens, }athyrogene, and hemagglutinins. Considerable qualitative infor- mation on these compounds in available. However, very little available quantitative information is suitable for incorporation into a Late base on the composition of foods. This lack of information results, at least in part, from the absence of a systematic effort to gather information suitable for incorporation into such data bases. Con- siderable research on and development of appropriate analytic methods will probably be necessary to obtain the data. The development of tats on nonnutritive components in food would benefit the users of national survey data on food consumption and dietary intake. Earlier in this report, the Committee has recommended the development of appropriate analytic methods and expansion of a standardized data base on the composition of foota. Similar recommendations are applicable to the longer-term development of standardized data on nonnutritive food components.
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— 94 — FOOD INGRED TENTS Little quantitative information on foot ingredients is availab le in a form suitable for incorporation into Fate bases on the composition of foods. In most cases, such technical data will be relatively difficult to acquire, because the number ? kinds, and amounts of these compounds may depend as heavily on the food production process as on the food product formulation. The Committee does not expect the immediate addition of quantitative infor- mation about food ingredients into data bases on the composition of foods. However, the Committee recommends that such additions to data bases on the composition of foods be considered as a longer-term goal. Committee recommendations for the development of appropriate analytic methods ant expansion of a standardized data base on the composition of foods are also applicable to the development of standardized data on food ingredients. INADVERTENT COMPONENTS OF FOODS Concern about the chemical contaminants that directly or indirectly enter the food sys tem is increas ing . For example, chemical s pit Is can contaminate individual food products . Compounds can enter the food sys tem through contam- ination of water or by soil, microbial organisms, or molds. Examples of subjects of concern are heavy metals and aflatoxins in foods. Few data are available on the amounts of these compounds 1 ikely to be found in foods . Much current knowledge on these compounds is obtained from data on the regulatory recall of contaminated foods. But quantitative data originating from recall actions may not be useful for standardized data bases on the come position of foods. Recall-related data involve foods that were not eaten, but rather were recalled from the food supply because of the presence of sub- stances in amounts higher than permitted. Moreover, current analytic methods used to measure such substances may be designed solely to determine whether the amounts of these substances were greater than some particular specified amounts. Those methods to not yield good data on the usual or expected amounts of substances that occur in amounts Smaller than the amounts resulting in product recalls. Future data users would benefit if analytic data on the usual or expected amounts of chance contaminants were available in a standardized data base on the compos ition of foods . The Committee does not believe that it is feasible to expect the immediate addition of quantitative information on inadvertent food components to data bases on the compos ition of foods . However, the Committee recommends, over the longer term, a systematic approach to the
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- 95 development of this information. Committee recommendations for the development. of appropriate analytic methods ant an expanded data base on the composition of foods are applicable to the development of standardized data on inadvertent components of foods . GENERAL USER NEEDS The data users' conferences were designed specifically to develop infor- mation on and recommendations for modifications in survey methods. However, the Committee has chosen to include recommendations on come general user needs that were identified during its own information gathering process. The recom- mendations included here are related to storage and maintenance of data tapes. Implementation of these additional but more general recommendations, although not specifically a part of the Committee's charge, would also serve the needs of future data users. The Committee therefore urges their consideration. DATA TAPE STORAGE . The use of these data for analyses of changes in food consumption, dietary intake, and health status with time and their use for other trend analyses imply a continuing need for the data tapes over time. Some users have sug- gested the need to ensure the storage and maintenance of data base tapes to prevent their physical deterioration. This suggestion may also be applicable to other data taper and is not of interest solely when data are collected on food consumption, dietary intake, and health status. The Committee suggests review of the technology of data tape storage. It further suggests that the agencies undertake continuing efforts to ensure that the information collected and stored on these tapes be protected from physical deterioration. The Committee suggests that USDA, DHHS, and other interested agencies, along with representatives of the National Archives and Records Service, consider the technical means that may be needed to ensure that data tape information from federally funded surveys be stored and maintained in a manner most likely to prevent their physical deterioration. SUGARY In addition to recommendations for near-term implementation, the Committee has addressed data users' needs that are likely to be implemented over a longer-term. The Committee accepts the premise that these additional recom- mendation~ will require both time and research resources. However, it urges
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- 96 - their full consideration. The Committee has u~ed the purposes of the separate surveys as guides for identifying the agencies most likely to be involved or to be feat agencies in implementation of there recommendations. Data users have identified several needs for data that are related to food intake methods, including the need for continuing support of methodologic investigation, the need for detailed identification and description of foods consumed by survey subjects, the need for more detailed identification of medications taken by survey subjects, and broader information on impediments to food intake. The Committee recommendations related to these user needs are based, in general, on their utility for users and with recognition of the need for research or personnel resources before their implementation. Some users also identified needs for more detailed and highly specific information on the composition of foods. Although the Committee regards the collection of these data as worth while, it expects broad expansion of the public data base on the composition of foods to require a continuing, long- term commitment to the resource needs of such an ef fort . Some general user needs are also included in the Comer ittee 's recommen- dations. Although not specifically within the Connnittee's charge, the general recommendations are des igned to respond to needs of both current and future data users for more detailed and long-term use of survey data. .
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~ 97 — Tab le 7-l . State of Me thods for Nutrient Analys is in Foodoa Probab it ity o f Correct Analy~cic Value Category High Good Fair Poor Carbohydrates, Fiber, Individual Fiber and Sugars - Sugars S tar ch Lipids Choles terol Sterols Total Fat Homeric Fatty Acids Common Fatty Acids Minerale/lnorganic Calcium Total Iron Arsenic Cobalt Nutrients Copper Selenium Chromium Molybdenum Magnes ium Fluor ine S i 1 i con Phosphorus lotine Tin Potass ium Manganes e Vanadium Sodium Heme Iron Zinc Nonheme Iron Proteins and Total Most Amino Some Amino Amino Acids Nitrogen Acids Acids Total Protein Vitamins Niac in Ribof lavin ~hiamin Vitamin B6 Vi tamin A Carotenes vitamin B12 Vitamin C Vitamin D Hi tamin E Folacin Pantothenic Acid Biotin Cho 1 ine Vi tamin R aAdapted from Stewart.38
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Representative terms from entire chapter: