Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 79
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification 5 Guiding Principles for Selecting Reference Values for Nutrition Labeling The principal task for the Committee on Use of Dietary Reference Intakes in Nutrition Labeling was to provide guidance in translating the science in the Dietary Reference Intake (DRI) reports to reference values that could be used for the next revision of nutrition labeling regulations. The previous chapters have provided an overview of the task, history, and present status of nutrition labeling—in essence the context within which the committee conducted its deliberations. This chapter provides ten principles the committee has developed to guide the establishment of updated reference values for nutrition labeling. The committee’s approach to how the DRIs would be used as reference values for nutrition labeling was defined within the sponsors’ contract language. In particular, this language specified that the purposes of reference values on food labeling are to enable consumers to compare the nutrient content of different food products and to determine the relative contributions of a food to an overall health-promoting diet. The information in nutrition labeling is not intended to be used to plan individual diets. The committee was to identify general guiding principles for use in setting nutrient reference values for nutrition labeling in consideration of the stated purposes. It was to do this by assessing the objectives, rationale, and recommendations for the methodology to select reference values for the nutritive value of food to appear in the Nutrition Facts box. The committee therefore has developed its recommendations using as its main reference materials the nutrient-specific DRI reports (IOM, 1997, 1998, 2000b, 2001, 2002a), the DRI derivative reports
OCR for page 80
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification on applications in dietary assessment (IOM, 2000a) and in planning (IOM, 2003), and the preambles, text, and other background materials of appropriate labeling regulations from the United States and Canada. The committee presents its recommendations as guiding principles—it does not provide nutrient values. Any numbers in the text related to the guiding principles are illustrative only. It is not the committee’s responsibility, or its intent, to make regulatory recommendations. Rather the guiding principles provided in this report were developed as science-based recommendations for the sponsors to accept or reject as appropriate to their own activities. GUIDANCE ON DEVELOPING REFERENCE VALUES Using the Percent Daily Value GUIDING PRINCIPLE 1. Nutrition information in the Nutrition Facts box should continue to be expressed as percent Daily Value (% DV). Section 2(b)(1)(A) of the Nutrition Labeling and Education Act of 1990 (NLEA) (104 Stat. 2353, 2356) requires that nutrition labeling be designed so that it “… enables the public to readily observe and comprehend such information and to understand its relative significance in the context of a total daily diet.” The Food and Drug Administration (FDA) developed the percent Daily Value (% DV) concept to meet this requirement. The % DV was modeled on the “percentage of the U.S. Recommended Daily Allowance,” an approach used in the 1973 version of nutrition labeling to help consumers understand and compare the relative amount of protein, vitamins, and minerals in food. Studies in the United States and Canada do, in fact, support this (see FDA, 1993a; NIN, 1999), although increased educational efforts are needed to optimize its potential use as a consumer tool (Levy et al., 2000). The % DV was selected after careful study, including consumer research and review of public comments (FDA, 1993c). The committee found the rationale for the use of % DV compelling and offers no alternative approaches to the DV concept. The committee recommends that the nutrient content per serving of a food be expressed as a % DV whenever it is possible to establish this value for a nutrient. The committee notes that when it refers to the DV throughout this report, it recognizes
OCR for page 81
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification that the DV is a single term that refers to Reference Daily Intakes (RDIs) and Daily Reference Values (DRVs), which have distinctly different derivations and scientific bases.1 Defining the Population DRIs have been established for 22 distinct life stage and gender groups. These groups were created because the available data indicated that each group has a unique set of nutrient needs that differentiates it from the others (see “Life Stage Groups” in Chapter 4). When using the DRI reports to generate reference values for nutrition labeling of the food supply, the population base needs to better represent the general population through a combination of the distributions represented by these life stage and gender groups. The committee therefore recommends using a base population of individuals 4 years of age and older, excluding pregnant and lactating women, to represent the general population. By the time active children reach 4 years of age, their energy requirements are similar to the energy needs of small, less-active adults (IOM, 2002a). Also, in an earlier review, FDA reported that by 4 years of age children’s food-consumption patterns are similar to those of adults (FDA, 1993c). The committee considered whether current scientific information indicates that children in North America are assuming adult eating patterns at a younger age. However it did not find evidence from food-intake studies to support moving this age division for the general population (Birch, 1999; Milner and Allison, 1999; Nicklas et al., 1991). The committee did identify four distinctive life stage groups that should be considered for nutrition labeling; they are defined in Guiding Principle 8. 1 The RDI “… denote(s) those nutrients whose label reference values have been derived from the National Academy of Sciences (NAS) Recommended Dietary Allowances (RDAs) and Estimated Safe and Adequate Daily Dietary Intakes” (FDA 1993c, p. 2208). DRVs are label reference values originally established for eight nutrients for which there were no NAS RDAs at the time. Based on a body of scientific literature linking diet and the risk of chronic disease, FDA established DRVs as label reference values for total fat, saturated fat, cholesterol, total carbohydrate, dietary fiber, sodium, potassium, and protein based on a 2,000 calorie diet (FDA, 1993c).
OCR for page 82
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification Using a Population-Weighted Reference Value GUIDING PRINCIPLE 2. The Daily Values (DVs) should be based on a population-weighted reference value. As noted above, a single reference value is most appropriate for the Nutrition Facts box, but this value must be designed to be meaningful for a base population that is 4 years of age and older. Even this smaller base population is comprised of 13 separate life stage groups in the DRI reports, excluding pregnancy and lactation. These groups are: all children ages 4 to 8 years and for males and females, separate groups based on the following age breaks: 9 to 13 years, 14 to 18 years, 19 to 30 years, 31 to 50 years, 51 to 70 years, and older than 70 years. Although the DRIs can differ for these groups, for many nutrients multiple groups have the same values. Because it is not practical to provide a DV for nutrition labeling for each of the 13 life stage groups, it is necessary to combine the DRIs for the groups to produce a single DV for the general population. The committee considered a variety of ways to compute the DV and concluded that the most scientifically valid approach was to apply weighting based on census data and the proportions of each life stage and gender group in the overall national population. A DV defined in this way will represent a central value of the requirement for the base population, with individual requirements varying around this value. The details are slightly different for nutrients with an Estimated Average Requirement (EAR), where the distribution of the requirements has been defined; for nutrients with an Adequate Intake (AI), where the distribution of requirements could not be defined; and for nutrients with an Acceptable Macronutrient Distribution Range (AMDR), where the reference values are expressed as a range. The rationale, however, is the same regardless of which DRI is provided: because the groups are represented in the base population in different proportions, the DRIs of the groups should be represented in the DV of the base population in the same proportions. Developing Reference Values Based on the Estimated Average Requirement GUIDING PRINCIPLE 3. A population-weighted Estimated Average Requirement (EAR) should be the basis for Daily Values (DVs) for those nutrients for which EARs have been identified.
OCR for page 83
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification The committee recommends that the DVs be based on population-weighted values of the EARs for the different life stage and gender groups. This is because the EAR represents the most accurate reflection of the true contribution of a particular food to total nutrient needs in the general population. A fundamental assumption underlying the committee’s recommendation is that the DV (expressed as % DV) is intended not only to help individuals compare different products within a food type, but also to help them understand nutrition information about foods “… in the context of a total daily diet” (NLEA, P.L. 101-535). To fulfill this function, the DV must take into account that nutrient requirements differ not only by life stage and gender group, but also within any single life stage and gender group. The best point of comparison for the nutrient contribution of a particular food to an individual’s total nutrient needs is the individual’s nutrient requirement, which is almost never known, but can be represented by the median of the requirement distribution (EAR). The logic is described in the following paragraphs. The recommendation that DVs be based on population-weighted EARs arose from the examination of two questions. First, given a distribution of requirements, how should a single numerical characterization be obtained? Second, given a collection of distributions of requirements corresponding to different subpopulations, how should these be combined to produce a single, meaningful DV? The true requirement of any one individual is almost never known, but it can be estimated from the DRIs. For nutrients for which the distributions of nutrient requirements for particular life stage and gender groups have been characterized, the best estimate of an individual’s requirement is the EAR for the life stage and gender group to which he or she belongs. This is because levels of intake above or below the EAR will have a greater likelihood of systematically over- or underestimating an individual’s needs. Mathematically, the most appropriate single numerical characterization of a distribution of requirements is typically the median. For symmetrical distributions, the median is equal to the mean. By definition the EAR is the median of the estimated distribution of requirements for a particular life stage and gender group (IOM, 1997); therefore the EAR represents the best estimate of the nutrient requirement for individuals within a specific life stage and gender group. The probability that any individual in the group has a nutrient requirement above the EAR is 0.5. This probability declines as requirement levels rise above the EAR, falling to 0.025 at the Recommended Dietary Allowance (RDA). The RDA overstates the needs for 97.5 percent of the population in terms of a specific
OCR for page 84
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification criterion of nutrient adequacy. Since the RDA is defined to be 2 standard deviations above the mean, a consequence of the normality assumption is that the RDA is 1.2 times the EAR. This distribution relationship is illustrated in Figure 5-1. For a nutrient with a normal (Gaussian) distribution of requirements and a 10 percent coefficient of variation (CV), the requirements of 95 percent of the population will be within 20 percent (2 standard deviations) of the EAR. Thus the EAR is clearly a better single numerical representation of the requirements for the vast majority of the individuals in the subpopulation than is the RDA. The second issue in calculating DVs based on the EAR is identifying the best approach for combining subpopulation distributions. Intake levels beyond an individual’s requirement have no demonstrable benefit. This argument, applied to the population as a whole, suggests that the DV should be the median of the population distribution of requirements. However in the DRI reports, the requirement distributions are given for subpopulations, not for the total population. FIGURE 5-1 Relationship of the distribution of the population requirements between the Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) for a hypothetical nutrient. Note that 95 percent of the population is within 20 percent of the EAR where 2 standard deviations (s.d.) = 20 percent. The coefficient of variation = 10 percent.
OCR for page 85
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification Because it is impractical to provide DVs on the nutrition label for each subpopulation, it is necessary to compute a single number that will summarize the distribution of requirements in the total population. The logic described above argues in favor of choosing a central value of the distribution as the DV. For symmetrical distributions, such as the normal distribution, the mean and the median are identical. However the distribution of requirements for the population, derived from the distributions for the subpopulations, in general will not be symmetrical (see Chapter 4). Therefore the median, with 50 percent of the requirements above and 50 percent below, is preferred to the mean, which is sensitive to extreme values of requirements. In summary, the DV should be defined as the median of the population distribution of requirements. This is represented by the population-weighted EAR for nutrients where the distribution of requirements is known. Derivation of this value takes into account the relative proportions of the population in each of the 13 life stage and gender groups that comprise the target population for the Nutrition Facts box and the EAR and the CV of the requirement distributions for each group. To compute the population distribution of requirements for the DV, the subpopulation distributions are combined using weights obtained from census data. The DV is the median of this resulting distribution. This procedure is easily adapted for different demographic profiles, such as for the Canadian population or for different projected future populations (see Appendix B). Specifically, to calculate the population-weighted EAR for each subpopulation defined by life stage and gender, the requirement for each nutrient is assumed to have a distribution. For nutrients having an EAR, this distribution is assumed to be normal with the median equal to the EAR and a CV of 10 percent. Two exceptions are vitamin A and niacin, which have assumed CVs of 20 percent and 15 percent, respectively. The following text illustrates how the weighting could be approached for nutrients with CVs equal to 10 percent. Slight modifications are required for the two exceptions. Calculation Examples As an example, let the population of interest be females and males ages 4 years and older (excluding pregnant and lactating females) in the United States. As stated earlier there are 13 subpopulations with EARs in this population: all children ages 4 to 8 years, and for males and females, separate groups based on the following age breaks: 9 to 13 years, 14 to 18 years, 19 to 30 years, 31 to 50 years, 51
OCR for page 86
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification to 70 years, and older than 70 years. To calculate the population distribution of requirements, use (a) the distribution of requirements for each subpopulation, and (b) the proportions of each subpopulation in the population. The DRIs provide the distributions of requirements for the subpopulations. The subpopulation proportions are available from U.S. census data (Population Projections Program, 2000). The distribution of requirements for the population is called a mixture of the distributions for the subpopulations. There are 13 subpopulations; the index i with values 1 to 13 is used to distinguish them. Let πi denote the proportion of the population in subpopulation i and let Φi(x) denote the cumulative distribution function (CDF) for the requirements in subpopulation i. The quantity Φi(x) gives the proportion of the subpopulation with requirements less than or equal to x. The population CDF is thus: The median of the population requirement distribution is the value of x where Φ(x) = 0.5. There is no simple formula for this median. However, it is a simple task to calculate Φ(x) for a very large number of values of x. From these results the value of the median can be determined to any arbitrary number of significant digits. The probability distribution function (PDF) provides an alternative view of a distribution. To denote PDFs, φ(x) is used. The relationship between the population PDF and the subpopulation PDFs is similar to that for CDFs: As examples, the CDF and the PDF for vitamin E are depicted in Figure 5-2, and similar plots for riboflavin are depicted in Figure 5-3. Just as the EAR is the best estimate of an individual’s nutrient requirement, there is no single value that would be a better representation of the nutrient requirements of individuals in the population than the population-weighted EAR. The relevance of the population-weighted EAR in relation to the nutrient requirement of any one individual in the population is illustrated in Appendix Tables B-1 and B-2. Using U.S. population predictions for 2005, 54 to 85 percent of the entire population will have requirements that
OCR for page 87
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification FIGURE 5-2 Population cumulative distribution function and probability distribution function for the vitamin E requirement distribution. The vertical line represents the median.
OCR for page 88
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification FIGURE 5-3 Population cumulative distribution function and probability distribution function for the riboflavin requirement distribution. The vertical line represents the median.
OCR for page 89
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification are within 20 percent of the population-weighted EAR, and 72 to 95 percent will have requirements that fall within 30 percent of this value for the list of nutrients examined. Using Canadian 2006 population predictions, 55 to 86 percent will be within 20 percent and 73 to 96 percent will be within 30 percent of the population-weighted EAR. The observed ranges highlight two important differences among nutrients: (a) the variation in requirements within the life stage and groups, represented by the CV of the requirement distribution, differs among the nutrients, and (b) the requirements for some nutrients differ more markedly among life stage and gender groups than do others. For nutrients with considerable variation in requirements within and among gender and life stage groups (e.g., vitamin A), the “spread” around the population-weighted EAR is greater than for those nutrients that have requirements that are less variable (e.g., iodine). Nevertheless the modeling in Tables B-1 and B-2 confirms that a population-weighted EAR is relevant to the vast majority of individuals in the target population. Thus it provides a reasonable basis for a DV that individuals can use to evaluate the nutrient contributions of a particular food to the total diet. The Population-Weighted EAR and the RDA The committee’s recommendation to use population-weighted EARs as the basis for the DVs represents a move beyond past practice in light of new scientific evidence. Past practice based DVs on the highest of the RDAs or Recommended Nutrient Intakes for all individuals in the population. The logic behind this choice was to set a value that was high enough to cover the needs of almost every individual in the population. Because the RDA was set to include a margin of safety, it was considered a prudent choice for nutritional advice for the general public. Furthermore, when the existing DVs were set, the EAR concept had not been developed, and the only quantification of requirements was in the form of RDAs. In many cases using the highest RDA yields DVs that are so high that they are essentially irrelevant for most of the population. On the other hand, a rationale that has been given in support of using the highest RDA is that there should be some special attention given to the most vulnerable group, which is defined to be the group with the highest requirements, thought by some to be young children. Examination of the DRIs reveals, however, that the group with the highest requirements (with the exception of iron for women of childbearing age) is typically males, including young males. These high intake requirements are based on the rapid growth of this age
OCR for page 113
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification choices. For example, studies conducted by FDA during the design of the Nutrition Facts box found that while consumers preferred to have both % DVs and absolute amounts on the label, they did a better job using the label that contained % DVs alone (NIN, 1999). In addition, studies have repeatedly shown that when some consumers see large numbers next to a nutrient, they conclude that there is a large quantity of that nutrient in the food, regardless of the units of measure or the relative amount compared to the DV (FDA, 1993a). However the overall conclusions that have been drawn based on earlier research typically reflect consumers’ use of nutrition labeling without experience, education, training, or guidance. Recent studies have focused on the education of special populations. Training programs and studies with children and adults with diabetes (Baylor College of Medicine and Texas Children’s Hospital, 2001; Kessler and Wunderlich, 1999; Miller and Brown, 1999; Miller et al., 2002), patients with chronic heart failure (Neily et al., 2002), and clinically obese patients seriously striving for weight loss (Fishman, 1996) have demonstrated success in teaching patients to use the Nutrition Facts box to make appropriate food choices. With diabetes education in particular, the focus of training sessions, in priority order, is on: (1) serving size, (2) grams of total carbohydrate, and (3) grams of fat. For those diabetic patients who are trained to count carbohydrate grams, there is an added emphasis on grams of dietary fiber in nutrition labeling. For diabetic patients with renal complications, the training also includes a focus on grams of protein, total calories, and milligrams of sodium. In the United States most diabetic training, especially with children, does not use the % DV, but rather has the absolute amount as its focus (Personal communication, B. Schreiner, Baylor College of Medicine and Texas Children’s Hospital, 2003). The decision to add absolute amounts of micronutrients to the Nutrition Facts box should be based primarily on the information that will enable consumers to make healthy food choices. If making healthy food choices is the primary goal of the Nutrition Facts box, then adding absolute amounts should help achieve that goal. Therefore, the committee recommends that absolute amounts of micronutrients be added to the Nutrition Facts box because this addition has significant potential health value to the consumer. Units of Quantity Over time the scientific understanding of micronutrients has grown and the units of measure for expressing micronutrient quan-
OCR for page 114
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification tities have changed. In Table 5-3 proposed units for expressing DVs are provided for every nutrient that has an EAR or an AI. The following guidelines were used in deciding what the proposed units should be: The unit of quantity for nutrition labeling should be consistent with the EAR or AI. Thus the units for vitamin A, vitamin D, vitamin E, folate, and copper should be changed to reflect the new DRIs. Where the current unit is appropriate and consistent with the unit in the DRI report, it should be retained. For nutrients where there are no DRI values because the report has not been released (electrolytes), the current units should be retained. Implications of Changes to the Label Reference Values In response to the study task and perspectives presented at the workshops, the committee considered several implications of using the population-weighted EAR or AI or making other changes to reference values for food labeling. In particular the committee discussed nutrient content claims, saturated fat and cholesterol claims, health claims, food formulation, and overages. The committee does not intend for this section to reflect an in-depth review of these issues, but rather to highlight several areas where it recommends careful consideration of the impact of potential changes. The tables included in this section were developed using the formulas and methodology described earlier in this chapter and the illustrative examples of population-weighted values and population estimates from the tables in Appendix B. The resulting numerical values are illustrative only because the development of actual numerical values would necessitate discussions and decisions about the selection of the best representative numbers for each variable in the formulas. In addition, decisions about issues such as units, numerical rounding, population estimates, and certain aspects of the calculations would need to be made before calculations could be done to generate the actual numbers. While outside the direct task of the committee, nutrient content and health claims in the United States are dependent on the DVs. The workshop presentations helped to make it clear to the committee that manufacturers were concerned about the impact of changes in the DVs on the criteria for making nutrient content and health claims.
OCR for page 115
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification TABLE 5-3 Proposed Units of Quantity for Nutrients Nutrient Current Unit Proposed Unit Comment Change needed Vitamin A IU μg RAE DRI unit is RAE; carotenes will provide the sole source of vitamin A for vegans (show RAE in footnote) Vitamin D IU μg DRI unit is μg Vitamin E IU mg DRI unit is mg; the amount shown should be α-tocopherol Folate mg μg DFE Because fortified foods contain folic acid, this form should be converted to food folate using DFE calculation (show DFE in footnote) Choline mg AI unit is mg, but UL unit is g Copper mg μg DRI unit is μg No change needed Vitamin K mg Thiamin mg Riboflavin mg Niacin mg Although NE is the DRI unit, the label should only refer to preformed niacin Vitamin B6 mg Vitamin B12 mg Biotin mg Pantothenic acid mg Shorten name to pantothenate Vitamin C mg Calcium mg Magnesium mg Phosphorus mg Fluoride mg Chromium mg Iodine mg Iron mg Manganese mg Molybdenum mg Zinc mg Potential change unknown Sodium mg Units may change pending release of the DRI report on electrolytes Potassium mg Units may change pending release of the DRI report on electrolytes Chloride mg Units may change pending release of the DRI report on electrolytes NOTE: IU = international units, RAE = retinol activity equivalents, DRI = Dietary Reference Intake, DFE = dietary folate equivalents, AI = Adequate Intake, UL = Tolerable Upper Intake Level, NE = niacin equivalents.
OCR for page 116
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification New labeling regulations also make the following discussion of the proposed changes more relevant in Canada. Nutrient content claims have been permitted in Canada for food for special dietary use since 1974 and for all food meeting the compositional criteria for specified claims since 1988. For the first time, amendments to the Canadian Food and Drug Regulations (Canada, 2003) permit five health claims on food, including a claim for dental caries on the labels of certain chewing gums, candies, and breath-fresheners that contain a specified amount of fermentable carbohydrate. Nutrient Content Claims For a food to qualify to serve as a “good” source of a nutrient, it must contain 10 to 19 percent of the DV per reference amount customarily consumed (RACC). An “excellent” or “high” food source must contain at least 20 percent of the DV per RACC (21 C.F.R. 101.54(b), (c), (e). As shown in Table 5-4, the amount of nutrient per RACC for a food to qualify for a good or excellent/ high claim would be lower in most cases if the DVs were based on the population-weighted EAR or AI than if they were based on the current DVs. The example population-weighted EAR is similar to the current DV for vitamin C and lower for most other nutrients—by 22 (folate) to 66 percent (vitamin B12, copper, and iron). Because the units of measure for the DV and population-weighted EAR differ for vitamins A and E, it is not readily apparent how the qualifying amounts for these label claims might potentially differ. Population-weighted AIs for calcium, vitamin K, and fiber may be slightly higher by approximately 10 to 20 percent than the current DVs; the population-weighted AI would most likely be lower than the current DV for vitamin D (~30 percent), pantothenic acid (~52 percent), and biotin (~91 percent). Currently protein content expressed as a % DV and the criteria for protein content claims are based on the amount of protein in a food after protein digestibility-corrected amino acid scores (PCDAAs) are applied. The committee recommends that the reference value for protein be based on the difference between the sum of the reference values for carbohydrate (based on the midpoint of the AMDR for carbohydrate) and fat (based on the midpoint of the population-weighted midpoint of the AMDR for fat for children and adults). If a protein DV based on an AMDR of greater than 10 percent of energy was adopted, consideration would need to be given to the criteria for expressing protein content as a % DV, as well as to the
OCR for page 117
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification criteria for protein content claims. The committee discussed some of the implications—both with and without PDCAAs—of a 75-g DV on protein label declarations and criteria for protein content claims. Under the current regulations a good source of protein contains at least 10 percent of the DV per RACC. Therefore a good source of protein based on a DV of 75 g would require 7.5 g of protein per RACC. By way of comparison, a large egg contains 6 g of protein per RACC (50 g), peanut butter contains 8.1 g (2 tbs), and canned navy beans contain 9.7 g (130 g). With or without adjustment for PDCAAs, the egg would not qualify as a good source. Peanut butter would qualify as a good source if not adjusted for PDCAAs, but it would not qualify if adjusted (4.7 g/RACC by the Food and Agriculture Organization/World Health Organization pattern and 5.4 g/ RACC by the Food and Nutrition Board/Institute of Medicine pattern). Canned navy beans would qualify as a good source whether or not PDCAAs were adjusted (7.8 g by both patterns). In a mixed diet that contains ample protein, the correction factors probably are not important. However the factors would become important when evaluating an individual food’s contribution to protein intake—especially in circumstances where the diet lacks variety and is relatively low in energy content (e.g., when meal replacement drinks and bars are used in supplemental feeding or weight-management programs). Because of the complexities associated with evaluating the contribution of protein to a health-promoting diet, the committee suggests a thorough evaluation of the regulatory and nutritional implications of the use of PDCAAs in this context. Saturated Fat and Cholesterol Content Claims In general, the criterion for a “free” content claim is the lower limit of analytical accuracy for a given nutrient, the criterion for a “low” content claim is about 5 percent of the DV, and the criterion for a “reduced” content claim is at least 25 percent less than the reference food. A lower DV for saturated fat and cholesterol may reduce the amounts per RACC required to meet the criteria for free and low claims, perhaps making it more difficult to make these claims about food. It is therefore important to take into consideration that the ability to meet current criteria for reduced cholesterol claims also may be affected by a lower DV for saturated fat. Health Claims Specific Nutrient Requirements. Each health claim has specific nutri-
OCR for page 118
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification TABLE 5-4 Illustrative Comparison of the U.S. Daily Value (DV) and a Possible DV Calculated Using a Population-Weighted Approach Nutrient DV Good Excellent Nutrients that have a Population-Weighted EAR Vitamin A 5,000 IU 500 1,000 Vitamin C 60 mg 6 12 Vitamin E 30 IU 3 6 Thiamin 1.5 mg 0.15 0.30 Riboflavin 1.7 mg 0.17 0.34 Niacin 20 mg 2 4 Folate 400 μg 40 80 Vitamin B12 6 μg 0.6 1.2 Copper 2 mg 0.2 0.4 Iodine 150 μg 15 30 Iron 18 mg 1.8 3.6 Magnesium 400 mg 40 80 Molybdenum 75 μg 7.5 15 Phosphorus 1,000 mg 100 200 Selenium 70 μg 7 14 Zinc 15 mg 1.5 3 Nutrients that have a Population-Weighted AI Biotin 300 μg 30 60 Calcium 1,000 mg 100 200 Choline —f Chromium 120 μg 12 24 Fluoride —f Manganese 2 mg 0.2 0.4 Pantothenic acid 10 mg 1 2 Vitamin Dg 400 IU (10 μg) 40 (1) 80 (2) Vitamin K 80 μg 8 16 Fiber 25 g 2.5 5 NOTE: Good source and excellent source refer to nutrient content claims. Under current regulations, a food must contain 10 to 19 percent of the DV to serve as a good source of a nutrient. An excellent (or high) source must contain at least 20 percent of the DV. aEAR = Estimated Average Requirement, AI = Adequate Intake. bAs retinol activity equivalents (RAE). 1 RAE = 1 μg retinol, 12 μg β-carotene, 24 μg α-carotene, or 24 μg β-cryptoxanthin. The RAE for dietary provitamin A carotenoids is twofold greater than retinol equivalents (RE), whereas the RAE for preformed vitamin A is the same as RE. cAs α-tocopherol. α-Tocopherol includes RRR-α-tocopherol, the only form of α-tocopherol that occurs naturally in foods, and the 2R-stereoisomeric forms of α-tocopherol (RRR-, RSR-, RRS-, and RSS-α-tocopherol) that occur in fortified foods and supplements. It does not include the 2S-stereoisomeric forms of α-tocopherol (SRR-, SSR-, SRS-, and SSS-α-tocopherol), also found in fortified foods and supplements.
OCR for page 119
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification Population-Weighted EAR or AIa Good Excellent 529 μg RAEb 53 106 63 mg 6 13 12 mg α-tocopherolc 1 2 0.92 mg 0.09 0.18 0.95 mg 0.10 0.19 11.1 mg NEd 1.1 2.2 314 DFEe 31 63 2.0 μg 0.2 0.4 684 μg 68 137 93 μg 9 19 6.1 mg 0.6 1.2 286 mg 29 57 33 μg 3 7 588 mg 59 118 44 μg 4 9 7.5 mg 0.75 1.5 28 μg 2.8 5.6 1,091 mg 109 218 460 mg 46 92 27 μg 2.7 5.4 3.2 mg 0.32 0.64 2 mg 0.2 0.4 4.8 mg 0.48 0.96 6.9 μg 0.69 1.38 95 μg 9.5 19 28 gh 2.8 5.6 dAs niacin equivalents (NE). 1 mg of niacin = 60 mg of tryptophan. eAs dietary folate equivalents (DFE). 1 DFE = 1 μg food folate = 0.6 μg of folic acid from fortified food or as a supplement consumed with food = 0.5 μg of a supplement taken on an empty stomach. fNo DV established. gFor vitamin D, IU is the current unit of expression for nutrition labeling; μg is the unit of expression for the Dietary Reference Intakes. hBased on an AI of 14 g/1,000 kcal and 2,000 kcal reference calorie level.
OCR for page 120
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification ent criteria, among other criteria, for determining the eligibility of a food to make the claim. Generally a food must be a good or excellent/high source of nutrients associated with risk reduction and a low source of nutrients associated with increased risk (see Table 5-4) (FDA, 1993d). Table 5-5 summarizes selected nutrient requirements for health claims that may be affected by changes in the DV. Determination of possible effects on the criteria for sodium-and potassium-related claims is pending the DRI report on water and electrolytes. General Nutrient Criteria for Health Claims. In addition to meeting specific nutrient requirements to qualify for a health claim, a food must contain 10 percent or more of the DV, without fortification, for one of the following six nutrients: vitamin A, vitamin C, iron, TABLE 5-5 Current Nutrient Requirements for Health Claims Claima Nutrient Requirementsb Calcium and osteoporosis High in calcium Sodium and hypertension Low sodium Dietary SFA and cholesterol and CHD risk Low SFA Low cholesterol Fiber products, fruits, and vegetables and cancer Good source of fiber Fruits, vegetables, grains, and soluble fiber and CHD risk Low SFA Low cholesterol 0.6 g soluble fiber/RACC Fruits and vegetables and cancer Good source (without fortification) of one or more of vitamin A, C, or dietary fiber Folate and neural tube defects Good source of folate Soluble fiber from certain food and CHD risk Low SFA Low cholesterol Soluble fiber/RACC on nutrition label Soy protein and CHD risk Low SFA Low cholesterol Plant sterol/stanol esters and CHD risk Low SFA Low cholesterol Potassium and risk of high blood pressure and stroke Good source of potassium Low sodium Low SFA Low cholesterol aSFA = saturated fatty acid, CHD = coronary heart disease. bList includes only those possibly affected by a change in Daily Value. RACC = reference amount customarily consumed.
OCR for page 121
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification calcium, protein, and fiber. In those cases where the population-weighted EAR or AI is less than the current DV, more food products may qualify for a health claim. A higher DV for fiber, based on the AI for a 2,000-calorie reference value, however, may disqualify some food products from bearing a health claim. Disqualifying Nutrients. Food that contains more than a specified level of fat, saturated fat, cholesterol, or sodium are disqualified from making a health claim, even though all other criteria might be met. The disqualifying amount is typically 20 percent of the DV. Lowering the DV for saturated fat and cholesterol might make it more difficult for a food to qualify for certain health claims. DVs based on a population-weighted EAR or AI concept or other recommended principles may have mixed implications for claims in nutrition labeling under current regulatory criteria. Regardless, the committee believes that the principles presented in this report provide the most accurate scientific approach to using the DRIs to determine reference values for nutrition labeling. Effects of Nutrition Labeling on Food Formulation While discussions about the Nutrition Facts box typically revolve around its impact as a tool to help consumers make more healthful food selections, it must be recognized that the regulations governing the Nutrition Facts box and the associated nutrient content claims also influence the formulation of products. Manufacturers often adjust the quantities of particular ingredients or discretionary fortificants so that their products can be shown in the Nutrition Facts box to have a higher percent DV for some nutrients and a lower percent DV for others, thereby meeting the criteria for particular content claims. Thus any changes to the DV or to the list of nutrients included in the Nutrition Facts box can be expected to have some effect on the nutrient profiles of processed food. Furthermore, implementation of the recommended principles for discretionary fortification is expected to affect the inclusion of nutrients and their amounts suitable for fortification. Overages In the United States, for the purpose of determining compliance with nutrition labeling regulations, nutrients added to fortified or fabricated food (e.g., vitamins and minerals) are classified as Class I (21 C.F.R. 101.9(g)). A food containing a Class I nutrient is deemed to be misbranded if the amount of the nutrient in a composite
OCR for page 122
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification sample (collected and analyzed in accordance with regulations) is not at least equal to the value declared on the label. This requirement differs from that for Class II nutrients, which are those that naturally occur (i.e., are indigenous) in food. The nutrient content of a composite sample containing a Class II nutrient must be equal to at least 80 percent of the value declared on the label. In order to ensure compliance with label declarations, fortified nutrients are often added in excess (an overage). The amount of overage to ensure compliance depends on several factors, including the chemical stability of the nutrient itself, the manufacturing process (e.g., where in the process a vitamin or mineral is added; how well the vitamin or mineral is incorporated into the product; the conditions of time, temperature, pressure, and moisture), and the conditions used to simulate abusive handling throughout the distribution and retail chain (because manufacturers cannot control conditions after a product leaves their factories and distribution centers). In the United States reasonable excesses of vitamins and minerals over labeled amounts are acceptable within current good manufacturing practices. In attempting to comply with the regulation for Class I nutrients, some manufacturing practices may result in unnecessary, excessive overages. Excessive overages would be of concern for those nutrients with a low margin between the DV and the lowest UL and for which a serious adverse effect is the basis for the UL. Even in the absence of the potential for an adverse effect, excessive overages, which may not be captured in food composition databases, complicate the evaluations of nutrient intakes and nutritional status. Positive Health Message and Public Health Benefit in Nutrition Labeling The tone of the message conveyed by the elements in the Nutrition Facts box merits careful consideration because the box serves as an important public health communication tool. When the Nutrition Facts box is revised, the committee suggests that thought be given to the selection, organization, and display of nutrients as these elements may impact the tone of the public health message. The Nutrition Facts box currently can be construed as presenting a negative message because many of the required nutrients that appear in bold print on the top of the Nutrition Facts box (e.g., cholesterol, fat, and sodium) are those that consumers are expected to restrict in order to reduce their risk of chronic disease. There is no similar
OCR for page 123
Dietary Reference Intakes: Guiding Principles for Nutrition Labeling and Fortification emphasis made by grouping, format, or letter size of those nutrients for which consumers are encouraged to increase their intake (e.g., calcium). The priorities of required nutrient selection, label design, and other factors need to be reviewed in light of the potential positive message tone and educational value that could be presented for nutrients included on the label. In 1973 the selection of nutrients and food components to be included on nutrition labeling was primarily based on ameliorating nutritional deficiencies and on illustrating the positive and negative nutrient content of food. In 1990 FDA critically reviewed these nutrients, modified the list, and placed more emphasis on food components associated with chronic diseases and less emphasis on nutrient-deficiency diseases. In particular the revision placed emphasis on those nutrients that reflected the primary public health objective of a reduction in the risk of cardiovascular disease and the secondary objective of a reduction in the risk of cancer. Periodic reviews of the key scientific issues of public health significance and whether these issues are being addressed by nutrition labeling will help to maintain the scientific currency of the information provided to consumers. These reviews should include discussions with scientific experts to ascertain if the nutrients listed in the Nutrition Facts box reflect the most current scientific understanding of the nutrition, health, and disease relationships important for public health. Appropriate revisions to nutrition labeling should be considered based on these discussions. While changes in the nutrients required in the Nutrition Facts box can have significant ramifications for food manufacturers, the representation of public health issues and positive health messages only can be accomplished by these periodic reviews and, if necessary, revisions to the list of nutrients required in the Nutrition Facts box.
Representative terms from entire chapter: