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3 Nutrient Intake of WIC-Eligible Populations INTRODUCTION A major task in Phase I is to identify nutrients of concern among WIC-eligible subgroups. This task involves using the new Dietary Reference Intakes (DRIs) and the methods recently published by the Institute of Medicine (IOM, 2000a) to assess the nutrient adequacy of the diets of WIC-eligible subgroups. To date, no published studies have reported such analyses. As a result, the Committee conducted analyses applying the DRIs and the recommended methods to assess the nutrient adequacy of the diets of WIC-income-eligible subgroups--infants under age one year, children 1 through 4 years of age, adolescent women 14 through 18 years of age, and adult women 19 through 44 years of age--all from households with incomes in the range to be eligible for the WIC program (WIC-income-eligible subgroups). Although many of these households are already receiving WIC benefits, the intent of the analyses was to determine nutrients of concern to guide the Committee in recommending specific changes in the food packages during phase II of the project. Nutrient adequacy involves determining whether the diets of the various subgroups meet their nutrient requirements without being excessive. This chapter first describes the DRIs and then discusses how they were used in assessing the diets of WIC-income-eligible subgroups. The final sections of the chapter describe the data set used in the analyses and present the results of the analyses. DIETARY REFERENCE INTAKES (IOM, 1997-2004) Over the past decade, knowledge of nutrient requirements has increased substantially, resulting in a set of new dietary reference standards called the Dietary Reference Intakes (DRIs) (IOM, 1997, 1998, 2000b, 2001, 2002a, 2004). The DRIs replace the earlier Recommended Dietary Allowances (NRC, 1989b) and are the appropriate standards to use in determining whether diets are nutritionally adequate without being excessive. 3-1
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3-2 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES Using the DRI for Micronutrients For micronutrients the DRIs include four reference standards--the Estimated Average Requirement, the Recommended Dietary Allowance, the Adequate Intake, and the Tolerable Upper Intake Level (IOM, 1997, 1998, 2000b, 2001, 2003a): · Estimated Average Requirement (EAR): an average daily nutrient intake value that is estimated to meet the requirement, as defined by the specified indicator of adequacy, of half the healthy individuals in the specified life stage and gender group. At this level of intake, the other half of the healthy individuals in the specified group would not have their nutrient needs met. Thus, the EAR is the estimated midpoint (i.e., median) of the distribution of the nutrient requirements for the population in question. · Recommended Dietary Allowance (RDA): an average daily dietary nutrient intake level that is sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals in the specified life stage and gender group. If the distribution of requirements in the specified group is assumed to be normal, the RDA is computed by adding two standard deviations to the EAR. · Adequate Intake (AI): When available scientific evidence is not sufficient to determine an EAR (and, thus, an RDA cannot be determined), then an AI that is assumed to be adequate is set for the nutrient. The AI is the recommended average daily nutrient intake value based on experimentally derived intake levels or approximations of mean nutrient intakes by a group (or groups) of apparently healthy people who are maintaining a defined nutritional state or criterion of adequacy.1 · Tolerable Upper Intake Level (UL): Many nutrients have a UL, which is the highest average daily nutrient intake level that is likely to pose no risk of adverse health effects to almost all individuals in the specified life stage and gender group. As intake increases above the UL, the potential risk of adverse effects increases. The absence of a UL does not imply that there is no potential for adverse effects resulting from high intake of the nutrient, but, rather, that the scientific evidence available at this time does not permit estimation of a UL. Three of the four DRIs--the EAR, UL, and, to a lesser extent, the AI--are appropriate to use in assessing the nutrient intakes of population subgroups (IOM, 1997, 1998, 2000b, 2001, 2002a, 2004). The RDA is intended to be used as a goal for daily intake by individuals and should not be used in assessing group intakes (IOM, 1997, 1998, 2000b, 2001, 2002a, 2004). Table 3-1 presents the DRIs for the micronutrients examined in the assessment of the nutrient adequacy of the diets of WIC-income-eligible populations. Age ranges in the table are inclusive of both the lower and upper ages (e.g., 1-3 years includes children from 1.0 through 3.9 years of age). Age groups used for the DRI reports are somewhat different from the participant groups in the WIC program and appropriate adjustments have been made in the calculations presented in this report to account for these differences.2 1 Examples of defined nutritional states include normal growth, maintenance of normal circulating nutrient values or biochemical indices, or other characteristics of nutritional well-being or general health (IOM, 1997, 1998, 2000b, 2001, 2003a). 2 Tables in the report list the appropriate DRI values for each subgroup within a WIC participant group. The age-appropriate and life stage-appropriate DRI values were used for each individual within a WIC participant group.
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-3 TABLE 3-1 Dietary Reference Intakes Used for Assessing Micronutrient Intakes of WIC- Eligible Subgroups Dietary Component Calcium Iron Zinc Magnesium Vitamin A Vitamin C Vitamin E Vitamin B6 (g/d) (mg/d) (mg/d) (mg/d) (mcg/d, RAE) (mg/d) (mg/d) (mg/d) Infants 0 through 6 mos AI* 0.32*d 0.27* 2* 30* 400* 40* 4* 0.1* UL ND 40 4 ND 600a ND ND ND Infants 7 through 11 mos EAR/AI* 0.34*d 6.9 2.5 75* 500* 50* 5* 0.3* UL ND 40 5 ND 600a ND ND ND Children 1 through 3 y EAR/AI* 0.5* 3.0 2.5 65 210 13 5 0.4 UL 2.5 40 7 65e 600a 400 200b,c 30 Children 4 through 8 y EAR/AI* 0.8* 4.1 4.0 110 275 22 6 0.5 UL 2.5 40 12 110e 900a 650 300b,c 40 Females 14 through 18 y EAR/AI* 1.3* 7.9 7.3 300 485 56 12 1.0 UL 2.5 45 34 350e 2800a 1800 800b,c 80 Females 19 through 30 y EAR/AI* 1.0* 8.1 6.8 255 500 60 12 1.1 UL 2.5 45 40 350e 3000a 2000 1000b,c 100 Females 31 through 44 y EAR/AI* 1.0* 8.1 6.8 265 500 60 12 1.1 UL 2.5 45 40 350e 3000a 2000 1000b,c 100 Pregnant females < 19 y EAR/AI* 1.3* 23 10.5 335 530 66 12 1.6 UL 2.5 45 34 350e 2800a 1800 800b,c 80 Pregnant females 19 through 50 y EAR/AI* 1.0* 22 9.5 290 550 70 12 1.6 UL 2.5 45 40 350e,f 3000a 2000 1000b,c 100 Lactating females < 19 y EAR/AI* 1.3* 7 10.9 300 880 96 16 1.7 UL 2.5 45 34 350e 2800a 1800 800b,c 80 Lactating females 19 through 50 y EAR/AI* 1.0* 6.5 10.4 255 900 100 16 1.7 UL 2.5 45 40 350e,f 3000a 2000 1000b,c 100 NOTE: EAR = Estimated Average Requirement, used when available AI = Adequate Intake, used when necessary, followed by an asterisk (*); ND = not determined, UL not determined due to lack of data of adverse effects; UL = Tolerable Upper Intake Level. aThe UL applies to preformed vitamin A only. bThe UL applies to synthetic forms of vitamin E obtained from dietary supplements, fortified foods, or a combination. cAs -tocopherol; applies to any form of synthetic -tocopherol. dFor infants 0 through 11 months of age, the AI for calcium presented in the table is for formula-fed infants. eThe UL for magnesium represents intake from pharmacological agents only and does not include intake from food and water. fThe UL for pregnant females 31 through 50 years of age is 300 mg magnesium/d and for lactating females 31 through 50 years of age is 265 mg/d. SOURCES: IOM (1997, 1998, 2000b, 2001).
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3-4 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES TABLE 3-2 Acceptable Macronutrient Distribution Ranges of WIC-Eligible Subgroups Range (percent of food energy intake) Macronutrient Children 1 through 3 y Children and adoles- cents 4 through 18 y Adults Fat 30-40 25-35 20-35 Carbohydrate 45-65 45-65 45-65 Protein 5-20 10-30 10-35 Using the DRI for Macronutrients For macronutrients, a somewhat different set of DRIs has been developed (IOM, 2002a). In the case of food energy, dietary requirements are expressed in terms of estimated energy requirements (EER). An adult EER is defined as the dietary energy intake needed to maintain energy balance in a healthy adult of a given age, gender, weight, height, and level of physical activity. In infants and children, the EER is defined as the sum of the dietary energy intake predicted to maintain energy balance for an individual's age, weight, height, and activity level, plus an allowance for normal growth and development. For fat, protein, and carbohydrate, the DRIs include Acceptable Macronutrient Distribution Ranges (AMDRs) for intakes as a percentage of dietary energy intakes (Table 3-2). In addition, the DRI reports recommend limiting the amounts of saturated fats and cholesterol for all individuals over the age of two years (IOM, 2002a). While trans fatty acids increase the risk of coronary heart disease in adults, they have not been specifically identified as a hazard in infants and children. However, the recommendation to limit trans fatty acids from processed foods in the diet (IOM, 2002a) is presumed to apply to all individuals regardless of age. The WIC Program, in general, and WIC food packages, specifically, should encourage participants to follow these general recommendations. Using the DRI for Other Dietary Components In addition to micronutrients and macronutrients, other dietary components have DRIs relevant to the this analysis of the dietary intakes of the WIC-eligible population. Potassium and fiber have an AI; sodium has an AI for infants under the age of one year and a UL for the other WIC-eligible subgroups; and the category of added sugars3 has a recommendation that the percentage of food energy from added sugars not exceed 25 percent. There is no dietary requirement for added sugars. 3 Added sugars have been defined by USDA as sugars and syrups that are added to foods during processing or preparation (Welsh et al., 1992). This definition is used in assessing dietary intake and is part of the tip of the Food Guide Pyramid--the part of the diet consumers are advised to use sparingly (USDA/DHHS, 1992). Examples of added sugars are granulated sugar, powdered sugar, brown sugar, raw sugar; corn syrup, high-fructose corn syrup, fructose sweetener, liquid fructose; maple syrup, pancake syrup; molasses, and honey. Examples of foods with added sugars are soft drinks, fruit punches, and similar beverages; cookies, cakes, pies; dairy desserts; and candy.
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-5 USING THE DRI TO ASSESS NUTRIENT ADEQUACY To assess the nutrient adequacy of population subgroups, two main questions are of interest: 1. What is the prevalence of inadequate intakes of particular nutrients? 2. What is the prevalence of excessive intakes of particular nutrients? In order to do this assessment the Committee needs to know the characteristics of the usual nutrient intake distribution. The population subgroups of interest are the WIC-income-eligible subgroups. What are the characteristics of the usual nutrient intake distributions? In order to describe the characteristics of the usual intake distribution, and to use the DRIs in assessing diets, it is important to have information on the distribution of usual nutrient intakes. The usual intake of a nutrient is defined as the long-run average intake of the nutrient by the individual (NRC, 1986). Usual intake is not observed; rather, dietary recalls provide data on observed nutrient intakes over some specified period of time. Observed daily intake measures usual intake with error (i.e., error has been introduced into the measurement) (NRC, 1986). Nutrient intake varies from day to day within an individual. This day-to-day variability is "noise," since what investigators are typically interested in is the individual-to-individual variability in usual nutrient intake. Because for most nutrients, the day-to-day variability in intakes can be larger than the individual-to-individual variability, it is very important to "remove" the effect of this additional variability when estimating the distribution of usual intakes (Beaton et al., 1979). The National Research Council (NRC, 1986) proposed a simple additive measurement error model that permits adjusting the data for the presence of the day-to-day variability of intakes. The NRC model assumes that the observed daily intake for an individual can be written as a deviation from the individual's usual intake. Researchers at Iowa State University (ISU) have developed and modified approaches that permit estimating the usual intake distributions with a higher degree of accuracy (Dodd, 1996). The method proposed by Nusser et al. (1996) is known as the ISU method for estimating usual nutrient intake distributions, and is now widely used by the nutrition community (see, for example, Beaton, 1994; Carriquiry, 1999; IOM, 2000a). Software packages are available that produce estimates of the mean and variance of usual intake in the group, as well as of any percentile of interest (see, for example, ISU, 1997). It is important to note that these software packages produce estimates of the usual intake distributions of groups and are typically not used to estimate usual intake of individuals (ISU, 1996). What is the prevalence of inadequate intakes of particular nutrients? Assessing the prevalence of nutrient inadequacy in a group requires estimating the proportion of individuals in the group whose usual intakes of a nutrient do not meet requirements. The Committee used the EAR cut-point method to estimate the prevalence of inadequacy among WIC-income-eligible subgroups. The EAR cut-point method involves estimating the proportion of individuals in a group whose usual nutrient intakes are less than the EAR. It has been shown that, under certain assumptions, the proportion with usual intakes less than the EAR is an estimate of the proportion of a group whose usual intakes do not meet requirements (Beaton, 1994; Carriquiry, 1999; IOM, 2000a). In the case of any nutrient with more than one EAR that applied to a WIC participant group, the analytic approach to estimating the percentage with usual
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3-6 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES intakes less than the EAR involved (1) dividing individual-level observed intakes by the applicable EAR to obtain this ratio for each individual, (2) adjusting the distribution of the intake:EAR ratio using the usual intake adjustment software, and (3) estimating the percentage with the adjusted ratio less than 1. The Committee used this approach in the calculations for children 1 through 4 years of age,4 for vitamin C in smokers and non-smokers,5 and, in some cases, for pregnant and lactating women.6 Given the available information about the distribution of requirements for most nutrients, it appears that the underlying assumptions of the EAR cut-point method hold for most nutrients except iron in pre-menopausal women and food energy. To assess iron adequacy, the probability approach proposed in the NRC report (1986) was used as recommended in the DRI report on iron (IOM, 2001). The probability approach takes account of both the distribution of requirements and the distribution of usual intakes in estimating the prevalence of dietary iron inadequacy in a group (NRC, 1986; IOM, 2001).7 In applying the probability approach to estimating the prevalence of iron inadequacy, the Committee used recent data on the distribution of iron requirements (IOM, 2001). The distribution of iron requirements were not reported for pregnant or lactating women (IOM, 2001); therefore, the percentage of inadequacy of iron intakes was not estimated for these women. In the case of food energy, requirements are expressed in terms of estimated energy requirements (EERs). Since populations in balance should have usual intake and EER distributions with roughly equal mean values, the analysis compares the mean usual intake of food energy with the mean EER for each subgroup to assess energy adequacy. In addition, for fat, protein, and carbohydrate, tables present the usual distributions of intake as a percentage of food energy intake and estimates of the proportion less than the AMDR. 4 The DRI subdivide children into two life stage groups, (1) one through three years of age and (2) four through eight years of age. Thus WIC-eligible children, one through four years of age, fall into two life stage groups with the result that more than one EAR applies to this WIC participant group for most of the nutrients used in these analyses (iron, zinc, magnesium, vitamin A, vitamin C, vitamin E, vitamin B6, and protein) (IOM, 1997, 1998, 2000b, 2001, 2002a, 2004). 5 Because oxidative stress and metabolic turnover of vitamin C are increased in smokers, the recommended intake of vitamin C is increased by 35 mg per day (IOM, 2000b). Thus more than one EAR applies to WIC participant groups that include smokers and non-smokers. 6 EAR are different during pregnancy and lactation for some of the nutrients used in these analyses (iron, zinc, magnesium, vitamin A, vitamin C, vitamin E, vitamin B6, vitamin B12, and protein,) (IOM, 1997, 1998, 2000b, 2001, 2002a, 2004). Although, the data for pregnant and lactating women are combined for these analyses (Tables 3- 8 and 3-10), the applicable EAR was used in the calculation for each individual. Additionally, EAR during pregnancy or lactation vary according to the woman's age for a few nutrients used in these analyses (vitamin C, iron, magnesium, and zinc) (IOM, 1997, 1998, 2000b, 2001, 2002a, 2004). Again, the applicable EAR was used in the calculation for each individual. 7 In the technique (IOM, 2001) used for the analyses in this report for applying the probability approach, a probability of inadequate iron intake (IOM, 2001; Table I-7) is associated with the estimated usual intakes that fall within a certain range (percentile) of observed intakes (IOM, 2001; Table I-4). Combining the associated probabilities of inadequacy across a subgroup then gives the overall percentage of the subgroup with inadequate usual intakes. For the analysis of iron intakes for women, the Committee used the probabilities of inadequacy associated with the ranges of usual intake distribution for mixed populations of menstruating women, either adolescent (IOM, 2001; Table I-6) or adult (IOM, 2001; Table I-7). These mixed populations represent 17 percent oral contraceptive users and 83 percent non-oral contraceptive users as found appropriate from 1995 national survey data (Abma et al., 1997; IOM, 2001).
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-7 For micronutrients without an EAR--that is, for nutrients with an AI--usual intake distributions are presented and mean intakes are compared with the AI. However, for nutrients with an AI, it is important to note that limited inferences can be made regarding the prevalence of inadequacy. If mean intake levels are equal to or exceed the AI, it is likely that the prevalence of inadequacy is low; but if mean intakes are less than the AI, no conclusions can be drawn about the prevalence of inadequacy (IOM, 2000a). In addition, it is possible to infer that the proportion of individuals with usual intakes that exceed the AI is a lower boundary on the prevalence of nutrient adequacy in the group. Most of the AIs for infants are based on the nutrient content of human milk. One exception is calcium, where separate AIs are specified for formula-fed infants (0.32 g/d for 0 through 6 months of age; 0.34 g/d for 7 through 11 months of age) (Table 3-1) versus breastfed infants (0.21 g/d for 0 through 6 months of age; 0.27 g/d for 7 through 11 months of age). Other exceptions are the iron and zinc requirements for infants 7 through 11 months of age, where the content of breast milk is inadequate for most infants (Krebs, 2000; Dewey, 2001; Krebs and Westcott, 2002). Therefore, foods supplying both iron and zinc are needed for all 7- through 11- month old infants, whether breastfed or not. Sources of fortificant zinc should not exceed the UL; this may be a problem with formula-fed infants. What is the prevalence of excessive intakes of particular nutrients? The proportion of WIC-income-eligible subgroups with usual intakes exceeding the UL is an estimate of the proportion of each subgroup at risk of excessive intake levels. This research question of estimating the risk of excessive intake levels can be addressed only by using ULs; however, ULs have not been established for all nutrients. In addition, since some ULs refer to intakes from supplements, and since the data used in the analyses presented in this chapter (see below) do not include intakes from supplements, those nutrients could not be thoroughly evaluated with respect to the percentage exceeding the UL. Specifically, the Committee estimated the proportion at risk of excessive intake levels for calcium, iron, zinc, preformed vitamin A, vitamin C, and vitamin B6, but not for magnesium and vitamin E. In addition, for fat, protein, and carbohydrate, the committee analyzed the usual distributions of intakes as a percentage of food energy intake and estimated the proportion above the AMDR. Data Set The primary data sets used in these analyses are the 1994-1996 and 1998 Continuing Survey of Food Intakes by Individuals (CSFII) (FSRG, 2000).8 The 1994-1996 CSFII provides information on food and nutrient intake over two non-consecutive days for 16,103 individuals of all ages and gender, and of a variety of income levels, racial and ethnic groups, and sociodemographic characteristics (Tippett and Cypel, 1997). The survey, conducted over three years, was designed so that the information collected on any one year would constitute a nationally representative sample of individuals of all ages. The samples were selected using stratified, clustered multi-stage sampling procedures, with an over-sampling of low-income individuals. Food intake data were collected using 24-hour dietary recalls, which included information on the type and quantities of all foods consumed by individuals over two non- consecutive days and the nutrients derived from those foods. The CSFII data sets do not include 8Dietary supplement use was not part of the analyses on this data set.
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3-8 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES intake from dietary supplements such as multivitamin and mineral preparations. In addition, the 1994-96 CSFII survey provides sociodemographic information, including income and participation in food assistance programs (Tippett and Cypel, 1997). The overall response rates for the 1994-96 CSFII were 80% for the day-1 and 76% for the 2-day portions of the survey (Goldman and Nowverl, 1997). The 1998 Supplemental Children's Survey was designed to be a one-time supplement to the 1994-1996 CSFII, using the same design and survey methodology of the CSFII (Tippett and Cypel, 1997). Dietary intake data were collected from 5,559 infants and children aged 0 through 9 years over two non-consecutive days between November 1997 and October 1998. The sample was designed to be a stand-alone, nationally representative sample of children in that age range; also, however, it could be combined with the dietary information collected for infants and children up to nine years of age in the 1994-1996 CSFII. Combining the data from the 1998 Supplemental Children's Survey sample and the 1994-1996 CSFII provides a large sample of children for the Committee's analyses.9 Analysis Sample The analysis sample includes WIC-income-eligible respondents from the CSFII 1994-1996 and 1998 (FSRG, 2000) who completed 24-hour dietary recalls either for day-1 and day-2, or day-1 only. WIC-income-eligible respondents lived in households with income less than or equal to 185 percent of the federal poverty threshold and were in one of the following categorical subgroups: · Infants less than one year of age, non-breastfed: total (n = 626); WIC participants (n = 443); and income-eligible nonparticipants (n = 176).10 Because data on the quantity of breast milk consumed are not available, breastfeeding infants were excluded. Although breastfed infants must be excluded from the analyses in this chapter, breastfed infants were considered when feasible in the overall project, primarily in the analyses of nutrition-related health risks and outcomes described in Chapter 5. Because, iron, zinc, and protein have EARs for infants 7 through 11 months of age, this age group (n = 276) was analyzed separately for these nutrients in estimating the percentage with usual intakes less than the EAR. · Children 1 through 4 years of age: total (n = 2,800); WIC participants (n = 1,038); and income-eligible nonparticipants (n = 1,739). Breastfeeding children were excluded from the analyses. · Women of reproductive ages divided into three groups: 14 through 18 years of age not pregnant or lactating (n = 176); 19 through 44 years of age not pregnant or lactating (n = 751); and pregnant or lactating women 14 through 50 years of age (n = 57). Because of small sample sizes, pregnant and lactating women could not be analyzed separately. In addition, because of the small sample of pregnant and lactating women, the Committee placed more weight on the results for low-income women of reproductive age. Although the Committee analyzed both WIC-participant and eligible-nonparticipant subgroups, no noteworthy differences were observed in the data. The data were not analyzed to 9 The response rates are not readily available for the children participating in the 1994-96 CSFII (Tippett and Yasmin, 1997; Goldman and Nowverl, 1997) or the 1998 Supplemental Children's Survey (BARC, 2004). 10 The discrepancy between the total sample size of low-income infants under the age of one year and the sum of the sample sizes of WIC participants and income-eligible nonparticipants is because some respondents have missing data on WIC participation.
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-9 see if any small differences between the WIC participant and income-eligible-nonparticipant subgroups were statistically significant. The complete set of data is represented in Appendix A; however, only data on the total group (WIC-participants and income-eligible-nonparticipants combined) are presented in the body of the report. Nutrients and Dietary Components Selected for Analysis In order to choose which nutrients to consider in these analyses the Committee turned to several recent reports to find nutrients considered to be of public health concern (LSRO, 1995a, 1995b; FNS, 2003; IOM, 1997, 1998, 2000b, 2001, 2002a, 2002b). The following nutrients and dietary components were selected to be examined: · Nutrients previously targeted by the WIC program--calcium, iron, vitamin A, vitamin C, and protein (FNS, 2003); · Other nutrients considered of public health significance--magnesium, vitamin D, vitamin E, vitamin B6, folate, potassium, sodium, and fiber (LSRO, 1995a, 1995b; IOM, 1998, 2000b, 2004; Calvo and Whiting, 2003); · Macronutrients--food energy and the percentage of food energy from fat, carbohydrate, and protein (LSRO, 1995a, 1995b; IOM, 2002a); and · Components of dietary fat (LSRO, 1995a, 1995b; IOM, 2002a, 2002b; WHO, 2003), · Added sugars as a percentage of food energy (LSRO, 1995a, 1995b; IOM, 2002a; WHO, 2003). The following is an illustration of the route the Committee used to choose which nutrients to consider for analysis. The most recent report of the Interagency Board for Nutrition Monitoring and Related Research (LSRO, 1995a, 1995b) classified all of the food components listed in the bullets above as current or potential public health issues. The Committee found at least one other published report that also considered each of these nutrients as a current or potential public health issue. A second set of nutrients were also identified in theLSRO report as potential public health issues but were not examined by the Committee because other reports indicated the nutrients in this second set were not current or potential public health issues that are relevant to the WIC participants. The following are the nutrients listed in the LSRO report that were not analyzed by the Committee and the reasons are indicated: selenium intakes appear to be adequate in the U.S.11 (IOM, 2000; ATSDR, 2003a); fluoride is commonly ingested in water or oral health 11Dietary selenium varies depending on the selenium content of the soil in which plants are grown for human consumption or animal feed. There is substantial variability in the selenium content of any given food product. Food composition tables are based on average content of items from various sources; thus evaluation of dietary intakes in of selenium is inherently inaccurate. There is a potential for significant regional variability in selenium intake in North America; however, this has been largely buffered by the food distribution system in which extensive movement of food products protects individuals residing in areas with low-selenium soil from having low selenium intakes. Data from NHANES III show that serum levels of selenium in the U.S. population are quite adequate, with 99 percent of the population having levels at or above the cut point that is believed to represent maximum function in terms of selenium-dependent biochemical functions (LSRO, 1995a, 1995b; IOM, 2000).
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3-10 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES products rather than in food (IOM, 1997, ATSDR, 2003b); vitamin B12 is not considered a 12 nutrient of concern at the ages of participants in the WIC program (IOM, 1998); fat substitutes were not considered relevant to the WIC population; and alcohol was not considered relevant to the WIC food packages.13 Some isolated food components identified in the LSRO report were considered by the committee only as part of a larger category as follows: saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, trans fatty acids, and cholesterol are considered as part of total fat; and some carotenes were considered as part of total vitamin A RAE (retinol activity equivalents). Data Considerations Several important issues need to be considered when interpreting the results presented on the nutrient adequacy of WIC-income-eligible subgroups. First, there are differences across subgroups in the accuracy of 24-hour dietary recalls. Many studies have documented the underestimation of food energy intakes among adult subgroups, especially among overweight adults (Mertz et al., 1991; Johansson et al., 1998; Schoeller and Schoeller, 2002). To the extent that lower reported food energy intakes are related to lower nutrient intake levels, the prevalence of inadequacy is overestimated for subgroups that exhibit underreporting. In contrast to studies documenting underreporting by adults, some studies suggest that food and nutrient intakes are over-reported for young children (Devaney et al., 2004). If this over-reporting of food energy intakes is associated with higher nutrient intakes, the prevalence of inadequacy for these subgroups would be underestimated. Thus intake data are biased to some extent by under- reporting in data for adults and over-reporting in data for children and conclusions must be tempered by these limitations. A second data consideration concerns vitamin E. Fats and oils are major carriers of vitamin E, but they differ in their vitamin E content, and the amounts and types of fats and oils consumed are especially difficult to assess using diet recall methods (IOM, 2000b). A general data consideration in analyses of the dietary intake of any nutrient is that food composition databases contain mere estimates of the nutrient content of the foods actually consumed during dietary surveys. Because of the wide variations in the vitamin E content of fats and oils, additional concerns have been raised about the accuracy of the vitamin E values of foods in the food composition databases (IOM, 2000b). Thus, there are added reasons to question the accuracy of the reported vitamin E intakes in any data set utilized for the type of analyses described in this chapter. A third data consideration concerns folate. Folate intakes from the 1994-1996 and 1998 CSFII underestimate current folate intakes, since the data were collected prior to the mandatory folate fortification of the food supply. In addition, folate intakes from the 12 Dietary vitamin B12 is obtained primarily from foods that are of animal origin or that have been fortified (Herbert, 1988). Vitamin B12 deficiency can develop if the ability to absorb vitamin B12 is impaired; however, this problem is uncommon in individuals under 50 years of age (LSRO, 1995a). Thus vitamin B12 is not a concern except for individuals on primarily vegetarian diets (IOM, 1998; Herrmann et al., 2001; Obeid et al., 2002; Herrmann and Geisel, 2002; Hermann et al., 2003). The percentage of vegetarians in the general population is likely to be very low (ADA/Dietitians of Canada, 2003), 2.5 percent of the U.S. adult population in 2000 (VRG, 2000). The percentage of individuals following a vegan diet is lower (ADA/Dietitians of Canada, 2003), 0.9 percent of the U.S. adult population (VRG, 2000). Somewhat lower percentages of children (as young as six years of age) and adolescents have been reported to be vegetarian (VRG, 2001). 13 A few micronutrients were not classified as current public health issues. These included: iodine, thiamin, riboflavin, and niacin (LSRO, 1995a).
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-11 CSFII are not available as Dietary Folate Equivalents, which is the form in which folate recommendations are expressed. As a result, folate was not examined in these analyses of nutrient intakes, but is considered in Chapter 5. A final data consideration is vitamin D. The CSFII does not provide data on vitamin D intakes. As with folate, Chapter 5 presents evidence on vitamin D adequacy for the WIC target population. RESULTS AND DISCUSSION Infants Under One Year of Age For infants, requirements for many nutrients are expressed in terms of the AI and methods for assessing nutrient adequacy are limited primarily to comparing mean intakes to the AI. For all nutrients in Table 3-3, mean usual intake exceeded the AI (see below for nutrients in Table 3-3 with EAR). These findings are in agreement with the 2002 Feeding Infants and Toddlers Study (FITS) that used a different data set and found that mean (or median) intakes exceeded the AI for infants 3 through 6 months and 7 through 11 months of age (breastfed and non-breastfed infants combined) for the nutrients listed in Table 3-3 with the exception of potassium and sodium, which were not analyzed in FITS (Devaney et al., 2004). In fact, in both Table 3-3 and FITS, the 10th percentile of the usual intake distribution was equal to or exceeded the AI for the vitamins and minerals examined, suggesting that infants have nutritionally adequate diets. Three nutrients in Table 3-3--iron, zinc, and protein--have an EAR rather than an AI for infants 7 through 11 months. The estimated prevalence of inadequacy (percentage with usual intakes less than the EAR) for iron was 4.5 percent for low-income non-breastfeeding infants. The prevalence of inadequate zinc and protein intake among low-income non-breastfeeding infants was low, less than one percent. Again these findings are in agreement with the 2002 FITS that also found a low incidence of inadequate intakes for iron, zinc, and protein among infants 7 through 11 months (breastfed and non-breastfed infants combined) (Devaney et al., 2004).
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3-16 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES TABLE 3-6 Usual Food Energy Intakes and Estimated Energy Requirements: WIC-Income- Eligible Children, 1 Through 4 Years, Non-Breastfeeding Intake Distribution (percentiles and mean) 10th 25th Median Mean 75th 90th Usual food energy intakes (kcal/d) 1,049 1,240 1,476 1,516 1,750 2,037 EER-Low active (kcal/d) a 883 1,041 1,229 1,216 1,380 1,511 EER-Active (kcal/d) a 889 1,053 1,323 1,301 1,523 1,676 NOTE: EER = Estimated Energy Requirement. a For children ages 1 through 2 years an EER was calculated for each individual using body weight and the age-appropriate Energy Deposition factor (IOM, 2002a). For children ages 3 through 4 years an EER was calculated for each individual using age, body weight, height, the age-appropriate Energy Deposition factor, and the sex- and age-appropriate PA coefficient (Physical Activity coefficient) for the indicated PAL (Physical Activity Level; Low Active or Active) (IOM, 2002a). DATA SOURCE: Intake data are from 1994-1996 and 1998 CSFII (FSRG, 2000). The analysis sample from the CSFII data set included only respondents living in households with income less than or equal to 185 percent of the federal poverty threshold. EER are from IOM (2002a). Intake distributions were calculated using C-SIDE (ISU, 1997). TABLE 3-7 Macronutrients and Added Sugars: WIC-Income-Eligible Children, 1 Through 4 Years a Percent of Food Energy Intake Fat Protein Total Carbohydrate Added Sugars a 40% 20% 65% > 25% 16.8% 12.2% 0.6% 2.0% 5.0% 1.7% 4.3% a For added sugars, data were available only for children 2 through 4 years of age. The recommendation to limit added sugars to less than 25% of food energy intake is to be applied only to children 2 through 4 years of age. DATA SOURCE: Intake data used in calculations are from 1994-1996 and 1998 CSFII (FSRG, 2000). The analysis sample from the CSFII data set included only respondents living in households with income less than or equal to 185 percent of the federal poverty threshold. Recommendations are from IOM (2002a).
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-17 Females of Reproductive Age The diets of women of reproductive age had high levels of inadequacy (Table 3-8). The micronutrients with the highest prevalence of inadequacy were magnesium and vitamin E, where more than 75 percent of non-pregnant and non-lactating women had usual intakes less than the EAR. For vitamin E, the estimated prevalence of inadequacy for adolescent females was 100 percent. Vitamins A, C, and B6 had estimates of the prevalence of inadequacy between 25 and 53 percent for women 19 through 44 years of age. Two remaining micronutrients--iron and zinc-- had more moderate estimates of the prevalence of inadequacy. For females 14 through 18 years of age, only 10 to 11 percent have inadequate intakes of these two nutrients, while for women 19 through 44 years of age, 21 to 22 percent had inadequate intakes. It is noteworthy that inadequacy of iron intakes could not be evaluated for pregnant and lactating women due to technical considerations.14 For pregnant and lactating women, vitamin E had the greatest proportion of individuals whose diets were classified as inadequate. Magnesium and vitamin A had prevalences of inadequacy in the range of 50 to 60 percent, and vitamin C and vitamin B6 had lower prevalences in the range of 30 to 40 percent. Estimates of protein inadequacy were lower than for the other nutrients in Table 3-8. Less than 5 percent of low-income adolescent women had inadequate protein intakes. For low-income women 19 through 44 years of age and for pregnant and lactating women, the prevalence was somewhat higher but still moderate (17.4 percent for low-income women 19 through 44 years of age and 10.8 percent for pregnant/lactating women). For all subgroups, mean intakes of calcium, potassium, and fiber were far less than the AI, suggesting inadequate intakes. Although mean intakes below the AI do not necessarily imply nutrient inadequacy, when mean intakes are far below the AI, concerns about nutrient adequacy may arise. For calcium, potassium, and fiber, mean usual intakes are far below the AI. In fact, for low-income adolescent and adult women 19 through 44 years, even the 90th percentiles of usual intakes of these nutrients are below the AI, suggesting inadequate intakes. Reported intakes of food energy were less than the EER for women of reproductive ages, especially for low-income adult women (Table 3-9). For low-income adult women 19 through 44 years of age, mean reported food energy intake was more than 400 kcal less than the mean EER. The magnitude of this difference would imply a weight loss that has not been observed among low-income women, suggesting underreporting of food energy intakes by adult women. Results on the percentage of food energy from fat, protein, carbohydrate, and added sugars suggested that many adolescent females and almost a third of women 19 through 44 years of age had usual fat intakes outside the AMDR and had intakes of added sugars above 25 percent 14 As noted earlier in this chapter, due to limitations in the data set required for analysis of inadequacy of iron intakes using the probability approach, the percentage of inadequacy of iron intakes was not estimated for pregnant and lactating women.
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a b b b b b ne RAE y %.1 %.9 %.0 %.9 11 20 10 21 8%5. %.7 %.5 %.4 %.9 %.8 %.0 %.8 %.1 %.9 0% %.5 %.2 10 < 14-44 96 75 57 39 52 56 19 44 30 97 95 % } } } } } Wom y 18. 86. 59. .4 5 0 5 0 0 0 0 .0 .0 .0 10 26 30 26 50 55 90 60 70 10 12 12 16 -Eligiblee 31-44 a y 18. 86. 59. .4 5 0 5 0 0 0 0 .0 .0 .0 10 25 29 25 50 55 90 60 70 10 12 12 16 EAR 19-30 C-IncomI y W 97. 37. .5 .9 0 5 0 5 0 0 .0 .0 .0 10 10 30 33 30 48 53 88 56 66 96 12 12 16 14-18 Fiber: nda y 001. 001. 001. 19-44 AI y 301. 301. 301. Potassium, 14-18 y .3 Protein, 90th 980. 950. 291. .9 .7 .2 .7 .1 0 4 8 2 6 6 0 8 1 18 18 13 13 15 27 31 37 81 97 89 14 14 27 67. 69. 11 -44 14 ), eanm 75th 840. 760. 071. .7 .0 .5 .0 .7 1 9 2 4 9 1 0 0 0 15 15 11 11 13 24 25 32 66 68 75 11 11 19 27. 97. 98. and 730. 620. 910. .4 .6 .1 .4 6 7 2 7 9 1 21 21 27 55 56 64 89 85 6 13 12 10 49. 12 14 76. 66. 67. Micronutrients, tiles Mean ercen .8 .8 .3 3 8 5 9 2 6 83 76 4 Selected (pn 710. 580. 870. 12 11 99. 88. 12 21 20 26 52 48 61 12 76. 36. 07. Median of 25th 590. 440. 710. .5 10 29. 58. 07. .0 7 5 5 0 5 4 11 18 16 21 42 34 50 61 51 78 36. 05. 55. Distributioe tak .0 6 2 5 8 4 9 45 35 49 In 10th 500. 330. 570. 78. 47. 37. 75. 10 16 13 17 33 25 41 95. 04. 54. Distributions } } } } } } Intake b b b b b b b b b b b b ouprg y8 y4 y4 y4 y4 Usual Sub -141 y44- y81- y44- y81- y44- y81- 19 Pregnant Lactating 14 19 14 19 Pregnant Lactating 14 -491 y81- Pregnant Lactating 14 -491 y81- Pregnant Lactating 14 -491 y81- Pregnant Lactating 14 -491 Pregnant Lactating 3-8 um RAE) ientr per m as ) TABLE Nut (units day Calciu (g) onIr nc gnesia Animat cg Cnimat Enimat (mg) Zi (mg) M (mg) Vi (m Vi (mg) Vi (mg)
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b b %.5 %.6 %.1 t 10 25 36 4%4. %.4 %.8 ; . se 1) ne 17 10 anth 86 19 200, takni } } less dnani rcenep5 (ISU, 18 es (NRC, MO(I onri of womgniat amit 101. 601. 701. 38 aktin ach pro using withe ap edsuerewn C-SIDE acy tola equ rofd/gkg/660.d adni ans ltivum., equ or 101. 601. 701. 38 tag litybi actlrofg2.12 (e.g anth tedal uspl ts cu en rcenep stage. 001. 601. 701. 38 = EAR obarpehtgn atiolup polt ofegatn eary81h emlp esslem sup coin calerews dy and 14 < % age esgas etaryid ithwsdl tion bui 74. 74. 15. 25 28 29 s,tnelaviu usidetami adudexima for est tsne ehosuoh stridekat was an In 74. 74. 15. eq acc in ). 26 28 29 ity RAE irem perceehteroefrehtdna)1002, ghtiew life ugorht bogkg/501.d to cent es ording es.luav m froe dolar upso eseth takine ing on < requ gr EAR liv activl le ts 032. 082. 462. 86 88 94 92. 13. 83. 15 19 22 retino %eht, fod/htg iron sedab cludint 0042,a2 wei no en ofn licabp ined.b 200, was es 01 = E ironr tio OMI(nemow apeth com odyb dot 741. 721. 132. 76 75 87 52. 62. 33. 14 15 18 RA,tne Fo to nt take.ni kg/g170. EAReth seatad sponderylno 20, 00b or anth ); 20, 491. 441. 841. 68 64 79 22. 22. 82. 12 12 15 remiu tea stribuidethfo ngiattcal agelalfonemow werene na aredpm wom 0002 co lesst edduclin 9981 7, Reqe equ tiles nantg set was 199( 451. 381. 801. 67 62 79 22. 12. 82. inad 12 12 14 erag rcenep prerof egrprofg dual lactatingdna (FSRG, taadI MOI Av edta withe edta 21supl arenemowgniat perceneht tag ght indivih nt ofn CSFII69 201. 091. 501. 58 51 71 91. 71. 32. 11 9 11 egna CSFIeth estim wei eac pr Estim rcen act-lnon, e, edrtopreton of atioin morf = pe for nantg -194991 morfearIA 990. 870. 261. 51 42 64 71. 41. 91. 9 7 9 the age m and EAR,e of tivcu weresnte intake data lepm pre fro sa R the n- termede odr Th are } } } } tak rem sizes, In estimate lepm nor taade EA.dl b b b b b b b b tea y8 y4 y8 y4 y4 y8 an equ is repfonem quire n.emow RAE < analysise sa onri foneiot years.44 tak Th -141 -491 Pregnant Lactating -141 -491 y81- Pregnant Lactating 14 -491 Pregnant Lactating -141 y44- odybgkg/88.0sineiotrpr %eht prr ugh In: Ad 19 Pregnant Lactating = EAR wor of ).sn fo allms < of roth shoerthytrev Fo 19 OURCE aratio 6 Bnim re AI: % 1). es cn um ssia Fib NOTE The 200 nsoitubristdi esehtrofdetami RAE groups. est The not age calculateoT fosRAE S Because The ag DATA ). tal a b c all ltsu eprplare Vita (mg) Protei (g) Pot (g) To (g) EAR. IOM, The was of ad min polaredefethfo 9971
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3-20 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES TABLE 3-9 Usual Food Energy Intakes and Estimated Energy Requirements: WIC-Income- Eligible Women Intake Distribution (percentiles and mean) 10th 25th Median Mean 75th 90th Adolescents, 14 through 18 y Usual food energy intakes (kcal/d) 1,450 1,651 1,922 1,984 2,268 2,617 EER-Low Active (kcal/d) a 1,896 1,993 2,109 2,118 2,233 2,353 Adults, 19 through 44 y Usual food energy intakes (kcal/d) 1,162 1,408 1,710 1,756 2,053 2,407 EER-Low Active (kcal/d) b 1,970 2,048 2,148 2,185 2,280 2,447 NOTE: EER = Estimated Energy Requirement. a For adolescent women (14 through 18 years of age) an EER was calculated for each individual using age, body weight, height, the age-appropriate Energy Deposition coefficient, and the sex- and age-appropriate PA coefficient for the indicated PAL (Physical Activity Level: Low Active) (IOM, 2002a). b For adult women (19 through 44 years of age) an EER was calculated for each individual using age, body weight, height, and the sex- and age-appropriate PA (Physical Activity) coefficient for the indicated PAL (Physical Activity Level: Low Active) (IOM, 2002a). DATA SOURCE: Intake data are from 1994-1996 and 1998 CSFII (FSRG, 2000). The analysis sample from the CSFII data set included only respondents living in households with income less than or equal to 185 percent of the federal poverty threshold. EER are from IOM (2002a). Intake distributions were calculated using C-SIDE (ISU, 1997). TABLE 3-10 Macronutrients and Added Sugars: WIC-Income-Eligible Women Percent of Food Energy Intake Fat Protein Total Added Carbohydrate Sugars 35% 35% 65% > 25% Adolescents, 14 through 18 y 0.2% 27.7% 3.0% 0.0% 2.4% 0.8% 25.0% Adults, 19 through 44 y 1.4% 33.6% 1.9% 0.0% 14.4% 4.5% 19.2% Pregnant or lactating 0.0% 20.1% 0.4% 0.0% 1.5% 0.0% 2.2% DATA SOURCE: Intake data are from 1994-1996 and 1998 CSFII (FSRG, 2000). The analysis sample from the CSFII data set included only respondents living in households with income less than or equal to 185 percent of the federal poverty threshold. Recommendations are from IOM (2002a).
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-21 of food energy (Table 3-10). Only a small proportion had usual fat intakes less than the lower boundary of the AMDR for fat (20 percent), but more than a quarter of adolescent women and almost one-third of women 14 through 44 years had usual fat intakes exceeding the upper boundary. One-quarter of low-income adolescent women had intakes of added sugars that were greater than 25 percent of food energy. Excessive Nutrient Intake Table 3-11 presents estimates of the prevalence of usual intakes above the UL. In general, the risk of excessive intakes was low, less than 1 percent for most WIC-income-eligible subgroups. Some notable exceptions were: · Intakes of sodium appeared excessive. The percentages with usual sodium intakes above the UL were more than 80 percent of low-income children, more than 90 percent of low-income adolescent females and pregnant/lactating women, and nearly three-quarters of low-income adult women. It is noteworthy that the data set used for these analyses did not include dietary sodium added in the form of table salt. · High proportions of non-breastfed infants and small proportions of children ages 1 through 4 years had estimated usual intakes exceeding the UL for zinc and preformed vitamin A. The percentages with usual zinc intakes above the UL were almost 90 percent of low-income, non- breastfed infants and 15 percent of low-income children. The percentages with usual preformed vitamin A intakes above the UL were almost 40 percent of low-income, non-breastfed infants and 16 percent of low-income children. It is noteworthy that the data set used for these analyses did not include intake from dietary supplements.
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3-22 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES TABLE 3-11 Percentage of WIC-Income-Eligible Individuals with Usual Intake Above the UL. Women Infants < 1 y, Children non-breastfed 1 through 4 y Pregnant or 14 through 18 y 19 through 44 y Lactating (14 through 50 y) Calcium UL (g/d) 2.5 2.5 2.5 2.5 2.5 % > UL < 1% < 1% < 1% < 1% < 1% Iron UL (mg/d) 40 40 45 45 45 % > UL < 1% < 1% < 1% < 1% < 1% Zinc UL (mg/d) 4 7 34 40 40 % > UL 88.8% 14.9% < 1% < 1% < 1% Vitamin A, preformed UL (mcg/d) 600 600 2,800 3,000 2,800 % > UL 39.1% 16.4% < 1% < 1% < 1% Vitamin C UL (mg/d) ND 400 1,800 2,000 2,000 % > UL < 1% < 1% < 1% < 1% Vitamin B6 UL (mg/d) ND 30 80 100 100 % > UL < 1% < 1% < 1% < 1% Sodium UL (g/d) ND 1.5 2.3 2.3 2.3 % > UL 86.3% 93.1% 72.4% 98.9% NOTE: ND = not determined; UL = Tolerable Upper Intake Level (for infants, UL values listed in the table are for infants ages 0 through 6 months; for children, UL values listed in the table are for children ages 1 through 3 years). DATA SOURCE: Intake data are from 1994-1996 and 1998 CSFII (FSRG, 2000); data set does not include intake from dietary supplements (e.g., multivitamin and mineral preparations) or sodium intake from table salt. The analysis sample from the CSFII data set included only respondents living in households with income less than or equal to 185 percent of the federal poverty threshold. UL are from IOM (1997, 1998, 2000b, 2001, 2004). SUMMARY The results above provide a comprehensive analyses of the nutrient adequacy of WIC- income-eligible subgroups, focusing on the prevalence of inadequate nutrient intake, risk of excessive intake, and dietary imbalances. The results indicate inadequate intakes of key micronutrients; reported food energy intakes that differ from EERs; too high a percentage of food energy from fat; a low percentage of food energy from carbohydrate; inadequate intakes of potassium and fiber; and excessive intakes of sodium. Low-income infants and young children
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-23 had diets that are more nutritionally adequate than low-income adolescent and adult women of reproductive age. In interpreting these results, several analytic issues should be noted. First, CSFII data do not include nutrients from dietary supplements, which may reduce the prevalence of inadequacy estimated from dietary data alone, as reported in this chapter. Second, the difference between mean EER and mean food energy intakes for adolescents and adults suggested that some individuals were underreporting intakes. If food energy intakes were less than actual energy expenditures for specific subgroups, then individuals could not maintain their weight and these subgroups would then experience weight loss. Given the increase in the prevalence of overweight and obesity, however, underreporting of food intakes is the likely explanation for the difference between mean EER and mean food energy intakes. Given the likely underreporting of food energy intakes by adolescents and adults in general (Mertz et al., 1991; Johansson et al., 1998; Schoeller and Schoeller, 2002), an important question is the extent to which the prevalence of inadequacy for micronutrients was overestimated in these analyses for adolescent and adult women in the WIC population. The answer depends on the extent of underreporting and the correlation between food energy and micronutrient intakes. Nonetheless, given the very high prevalence of inadequacy for some micronutrients--vitamin E and magnesium in particular--and the low intakes of calcium, it is unlikely that underreporting of food intakes could explain fully the apparent inadequacies in the intakes of these nutrients (IOM, 2000b). For children, mean food energy intakes were considerably larger than mean EER for low- income children 1 through 4 years of age. Although the increasing prevalence of overweight and obesity among children was consistent with an excess of food energy intakes over requirements, the magnitude of the difference between mean intake and mean EER suggested that parents or caregivers over-report food intakes of children. To the extent that caregivers over-report the food intakes of children, the rates of inadequate nutrient intakes in this report are underestimates (Devaney et al., 2004). Dietary intakes of vitamin E were inadequate for large proportions of the population in the data sample. For example, among low-income adolescent women, the prevalence of vitamin E inadequacy was 100 percent; vitamin E was the only nutrient with a high prevalence of inadequacy among young children (over 50 percent). Other recent studies also reported inadequate dietary intakes of vitamin E in infants (Devaney et al., 2004), children (Devaney et al., 2004), school age children (Suitor and Gleason, 2002), adolescents (Suitor and Gleason, 2002), and adults (Maras et al., 2004). Vitamin E intakes were inadequate even when dietary supplements were included in the analysis (Devaney et al., 2004). Although clinical vitamin E deficiency is rare, low dietary intake of vitamin E may increase the long-term risk of chronic disease.15 Despite the data limitations regarding food composition and dietary intakes of vitamin E (discussed earlier in this chapter under Data Considerations) the committee cannot 15 Low dietary intake of vitamin E was correlated with an increase in the long-term risk of fatal coronary heart disease in adult populations as shown in a large 14-year longitudinal study in Finland (Knekt et al., 1994) and a large 7-year longitudinal study in Iowa (Kushi et al., 1996). However, dietary intake of vitamin E was not protective against myocardial infarction in a large 4-year longitudinal study in the Netherlands (Klipstein-Grobusch et al., 1999). Low intake of dietary vitamin E was correlated with an increased incidence of cardiovascular disease in two observational studies that also correlated the protective effect of dietary vitamin E with the plasma level of vitamin E adjusted for plasma lipid levels (Ford et al., 2003; Iannuzzi et al, 2002). That vitamin E in excess of recommended dietary guidelines does not have a protective effect was illustrated in a meta analysis of seven clinical trials utilizing supplemental vitamin E (Eidelman et al., 2004).
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3-24 PROPOSED CRITERIA FOR SELECTING THE WIC FOOD PACKAGES ignore the findings from the analysis of the dietary intake data--especially in light of the evidence of the beneficial effects of dietary vitamin E in reducing cardiovascular disease (Knekt et al., 1994; Kushi et al., 1996; Iannuzzi et al, 2002; Ford et al., 2003) and the possibility that vitamin E may serve an important antioxidant role during pregnancy (discussed under Nutrients and Improved Birth Outcomes in Chapter 5). For magnesium, the proportion with inadequate intake was high for low-income adolescent and adult women of reproductive age. Almost all adolescent women, more than three-quarters of low-income adult women in their childbearing years, and more than half of pregnant and lactating women were estimated to have inadequate magnesium intakes. Suitor and Gleason (2002) also found a high prevalence of inadequacy for magnesium among school-age children. Substantial proportions of low-income non-breastfed infants and some children had estimated usual intakes above the UL for zinc (89 and 15 percent, respectively) and preformed vitamin A (39 and 16 percent, respectively) indicating a possible risk of adverse effects. The methods used to set the UL in infants and young children for these two nutrients resulted in a narrow margin between the RDA and the UL (less than two times the RDA in the case of zinc). There has been no evidence of adverse effects from ingestion of zinc as naturally occurring in food (IOM, 2001). However, zinc is added to infant formula and also is used as a fortificant in foods that are commonly consumed by children (e.g., breakfast cereal). While certain animal-derived food sources can contribute to hypervitaminosis A, toxicity is rare without a supplemental source of retinol. Preformed vitamin A is used in infant formula and is also used as a fortificant in foods that are commonly consumed by children (e.g., milk).The finding that a considerable proportion of low-income non-breastfed infants and children had reported zinc and preformed vitamin A intakes that exceeded the UL reinforces the need to avoid unwarranted fortification and supplementation. Therefore, the Committee will consider the source of the nutrient (i.e., naturally-occurring versus fortificant) when proposing foods for the WIC food packages. This approach is in agreement with recommendations by the International Zinc Nutrition Consultative Group (Hotz and Brown, 2004). Finally, although the WIC-income-eligible subgroups had usual iron intakes with lower prevalences of inadequacy than most nutrients examined, it is important to recognize the large body of literature suggesting positive effects of WIC participation on iron intakes (Miller et al., 1985; Brown and Tieman, 1986; Rush et al., 1988a, 1988b; Sherry et al., 1997; Rose et al., 1998; Batten et al., 1990; Pehrsson et al., 2001). Thus, the absence of evidence of substantial iron inadequacy may reflect the success of the WIC program in improving iron intakes. While the discussion and caveats above clearly suggest caution in interpreting the results presented in this report, concerns persist about dietary inadequacies and excesses. Based on the detailed analyses results, the following nutrients are considered high priority. · Low-income infants under one year of age, non-breastfed: No nutrients were identified with a high risk of inadequacy; the prevalence of inadequacy was highest for iron, at 4.5 percent. Priority nutrients related to risk of excessive intakes in non-breastfed infants are zinc, preformed vitamin A, and food energy. · Low-income children 1 through 4 years of age: Priority nutrients identified as lacking in the diets of young children are vitamin E, fiber, and potassium. Nutrients that may be excessive in the diets of young children are zinc, preformed vitamin A, sodium, and food energy. · Low-income women of reproductive age: Priority nutrients identified as lacking in the diets of women 14 through 44 years of age are calcium, magnesium, vitamin E, potassium, and fiber. Nutrients with more moderate, but still high, levels of inadequacy are vitamins A, C, and B6.
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NUTRIENT INTAKE OF WIC-ELIGIBLE POPULATIONS 3-25 Nutrients with lower levels of inadequacy are iron, zinc, and protein. Sodium intakes and fat intakes as a percentage of food energy intakes are excessive in the diets of low-income women of reproductive age.
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Representative terms from entire chapter: