INSTITUTE OF MEDICINE
Food and Nutrition Board
January 28, 2015
Mr. Jay Hirschman
Director, Special Nutrition Services
Office of Analysis, Nutrition and Evaluation
Food and Nutrition Service
U.S. Department of Agriculture
Dear Mr. Hirschman:
The Institute of Medicine (IOM), in response to a request from Congress that the U.S. Department of Agriculture Food and Nutrition Service (USDA-FNS) review and assess the nutritional status and food and nutritional needs of the population eligible for the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and update the WIC food packages to be consistent with the 2015 Dietary Guidelines for Americans (DGA), considering the health and cultural needs of an increasingly diverse WIC population, while remaining cost-neutral, established the Committee to Review WIC Food Packages (the committee). This letter report is the first of three reports in this review, and builds on the previous committee’s work (IOM, 2006). In 2003, USDA-FNS asked the IOM to conduct a two-phase evaluation of the WIC food packages, including in phase I reviewing the nutritional needs of WIC participants and proposing priority nutrients and nutrition recommendations. In phase II the committee was asked to use its initial assessment to recommend specific changes to the WIC food packages. An important recommendation of the 2003 committee was to establish a program to allow purchases of vegetables and fruits, excluding white potatoes. In this letter report, the committee presents a reevaluation of the white potato exclusion, with consideration to the original rationale.
The current committee was charged with the following task (see Appendix B for the complete Statement of Task): To review the scientific literature published since the 2006 report as well as government reports and other relevant publications to assess the current WIC food packages for consistency with the DGA; review the nutritional requirements of the WIC population and conduct analyses of dietary and energy intakes; conduct analysis of food expenditures of the WIC population; review and assess the effect of cultural food preferences on nutritional needs and food intake patterns; and develop plans for cost analyses on WIC food package components, food group and subgroup costs, and information on program participation. Following this report, phases I and II of the Review of WIC Food Packages study will update the findings presented here, evaluate the current WIC food packages as outlined in the statement of task, and recommend updates, in the context of the 2015 DGA.
A component of the committee’s task, which is the subject of this report, was to evaluate the exclusion of white potatoes from purchase with the cash value voucher (CVV). This included assessment of nutrient and energy intake from white potatoes among WIC participants and WIC-eligible nonparticipants who are pregnant and breastfeeding and nonbreastfeeding postpartum women, and children ages 1 to less than 5 years.1 The analysis was to include a comparison of white potato consumption among these groups before and after the enactment of regulations in 2009, which allowed the purchase of vegetables and fruits (excluding white potatoes) with the CVV, against key recommendations of the 2010 DGA. Analyses were also to include nutrient intake referenced to the Dietary Reference Intakes (DRIs) and estimates of adequacy of nutrient intakes. Food intakes for each food group/subgroup represented in the 2010 DGA were also to be assessed. The Healthy Eating Index (HEI) 2010 and a second dietary quality index to be selected by the committee were to be used as comparators to assess healthy eating scores before and after exclusion of white potatoes from the WIC food package. A sensitivity analysis for WIC and WIC-eligible groups was to be conducted to assess nutrient and food group intake values relative to the DGA as well as to project changes in indicators of diet quality when fresh white potatoes are included in the WIC CVV. The committee was asked to make specific evidence-based recommendations, based on its evidence review and grounded in the most recently available science and reports. These recommendations should be consistent with the current DGA, consider the health and cultural needs of the WIC popula-
1 In phases I and II of this study, infants less than 1 year of age will be included in the population subgroups of interest.
tion, and be administered effectively and efficiently nationwide and in a cost-effective manner.
Approach to the Task
In response to its charge, the committee developed criteria, derived from the 2006 WIC report, but specifically applicable to the evaluation of white potatoes in the WIC food package. The criteria are as follows:
- The package reduces the prevalence of inadequate and excessive nutrient intakes in participants.
- The package contributes to an overall dietary pattern that is consistent with the DGA (for individuals ages 2 years and older).
- The package contributes to an overall diet that is consistent with established dietary recommendations for children 1 to less than 2 years of age.
- Foods in the package meet the health and cultural needs of the WIC population and can be administered effectively and efficiently nationwide in a cost-effective manner.
- Indexes of diet quality are not substantially altered when white potatoes are included in the CVV.
The committee engaged in a series of data and information collection and evaluation activities as described below. Applicable methodologies and underlying rationales are provided here and in the appendixes.
Public Data Gathering, Sponsor, and Public Comment Sessions
A data-gathering workshop, public comment session,2 and sponsor session were held October 14–15, 2014, in Washington, DC. Workshop presentations included information on national trends in the production and consumption of white potatoes; WIC voucher purchase patterns; nutrient content of white potatoes; nutrient bioavailability and relationships to health outcomes; and white potato products and processing. In the open meeting with the study sponsor, USDA-FNS staff provided up-to-date information on the design and implementation of the WIC program and its component parts and briefed the committee on the USDA’s expectations for this work (see Appendix C for the workshop and sponsor session agendas).
2 Public comments are accessible through the National Academies Public Access File. Email: email@example.com.
The committee developed an approach to review and evaluate the range of evidence available through general and focused literature searches. Because of limitations in time and resources, the committee was not able to conduct a systematic evidence-based review of the literature. Alternatively, the committee opted to conduct a comprehensive review of peer-reviewed published evidence, as well as of non-peer-reviewed evidence to identify relevant scientific and government reports. The committee also reviewed commissioned data collection and analyses of the response to the 2009 WIC food package implementation describing changes in food consumption of WIC participants, white potato consumption patterns, program administration issues related to exclusion of white potatoes from the CVV, health impacts related to white potato intake, and vendor and stocking issues linked to use of the CVV (see Appendix D for the search strategy). Additional evidence was gathered from the IOM reports on other nutrition assistance programs, childhood obesity, weight gain during pregnancy, and the DRIs, as well as a search of government reports for relevant information.
Nutrient profile evaluation The nutrient profile of white potatoes was assessed in relation to the nutrient profiles of other WIC-eligible vegetables and fruits. Vegetable and fruit group and subgroup nutrient profiles were compiled from the most recent USDA Center for Nutrition Policy and Promotion (CNPP) food pattern models (Personal communication, P. Britten, USDA/CNPP, December 9, 2014), along with selected representative foods to illustrate the range of nutrient levels provided by that group. Data for foods were sourced from the USDA National Nutrient Database for Standard Reference, Release 27 (USDA/ARS, 2014).
Nutrient and energy intakes and food group and subgroup intakes The primary source of data on food and nutrient intake was the What We Eat in America (WWEIA) component of the National Health and Nutrition Examination Survey (NHANES) (USDA/ARS, 2007–2010). The data used included dietary intake data (foods and nutrients from food sources but not from dietary supplements) and demographic information including age, gender, and physiological status, e.g., pregnant or lactating or postpartum women (0–6 months after delivery). The committee compared nutrient intakes to the DRIs to assess adequacy of nutrient intake.
Data on forms (fresh, frozen, canned, dehydrated without addition of fats, oils, sugar, or sodium) of white potatoes (which includes white, russet, red, yellow, fingerling, blue, or purple) typically consumed both at home and
away from home, and their respective proportions were also obtained from NHANES using the Food Patterns Equivalent Database (FPED), a file that identifies the food group and subgroup intakes associated with the DGA. Historical and recent trends in the production and availability of white potatoes and forms were evaluated using data from the USDA National Agricultural Statistical Service (NASS) and Economic Research Service (ERS). Analysis of NHANES was conducted for five low-income (defined as ≤ 185 percent of the poverty-income ratio) population subgroups3:
- Women, ages 19 to 50 years
- WIC participants,
- WIC-eligible (pregnant, breastfeeding, or postpartum) nonparticipants, and
- WIC-ineligible (neither pregnant, nor breastfeeding, nor postpartum) nonparticipants,
- Children ages 1 to less than 5 years
- WIC participants,4 and
- WIC-eligible nonparticipants.
These subgroups allow for comparison of nutrient and food intake of all individuals on WIC, compared to individuals who qualify, but do not participate in the program. In addition, WIC-ineligible, but low-income women could become eligible at a later time with a change in physiological status.
To assess nutrient and energy intakes among WIC participants, WIC-eligible, and low-income but noneligible population groups, the committee examined the 2007–2008, 2009–2010, and 2011–2012 NHANES datasets. Although the 2011–2012 dataset had been released as this report was in preparation, two critical components were not yet publicly available5:
3 PC Software for Intake Distribution Estimation (PC-SIDE) and the Iowa State University method were implemented to estimate usual intake distributions of nutrient and major food group intakes.
4 Capturing WIC participation is dependent upon accurate reporting in NHANES. The committee’s comparison of the weighted total number of recipients reporting WIC as well as extensive experience with reporting of program like WIC suggest that WIC use is underreported, and some WIC recipients are in group b or c for women and group b for children. There is also a challenge in identifying the low-income group as eligible: The concept of income reported in NHANES does not correspond to state-level income requirements for eligibility. Some individuals may be income ineligible but may still legitimately participate in the program if adjunctively or automatically eligible due to participate in Medicaid, Temporary Assistance for Needy Families (TANF), or the Supplemental Nutrition Assistance Program (SNAP).
5 An inquiry from the IOM to the USDA Agricultural Research Service indicated that the 2011–2012 NHANES FPED database would be released by the end of 2014. This was not compatible with timely delivery of this report.
(1) the identifier indicating which respondents report being WIC program participants and (2) the corresponding FPED, needed to determine DGA food group and subgroup intakes and to compute the HEI. Without these components the 2011–2012 NHANES dataset could not be used for this task. Therefore, only the 2007–2008 and 2009–2010 NHANES datasets were used for the analyses reported here.
Inspection of the NHANES data revealed that there were limited numbers of women of childbearing age, defined as 14 to 50 years old. Women ages 14 to 18 years were not included in the analysis because the data were not consistently available in NHANES to identify those among them who were WIC participants.6 Additionally, the subgroups of pregnant, breastfeeding, and postpartum WIC participants were too few in number for separate analyses. Therefore, the data were grouped as follows: (1) the 2007–2008 data were combined with the 2009–2010 data given that food intake was similar among women in both datasets; (2) women of childbearing age were considered to be those aged 19 to 50 for consistency across the combined datasets; and (3) data for pregnant, breastfeeding, or postpartum women were combined for all analyses. The analyses of nutrient and food intakes, therefore, evaluated all categories of women against the DRIs and food group recommendations for women who were neither pregnant nor breastfeeding.7 Similarly, children in the group 1 to less than 2 years of age were combined with those aged 2 to less than 5 years. Further details on the data analysis methodology are noted in the appendix data table footnotes.
For the five population subgroups delineated above, nutrient intake distributions were compared to the DRIs (IOM, 1997, 1998, 2000, 2001, 2002/2005, 2005, 2011a) (see Appendix E) and food group intakes were compared to the intakes of food groups as recommended in the 2010 DGA (USDA/HHS, 2010a). In this report, the committee focused on nutrients of concern as outlined in the 2010 DGA8 (USDA/HHS, 2010a). The intake of white potatoes was obtained through analysis of the intake of white potatoes eaten in all food items (through the FPED) of the WWEIA and matched into two forms: potentially WIC-eligible and not WIC-eligible. To be categorized as potentially WIC-eligible, white potatoes had to be consumed at home and eaten in food items likely to be prepared from ingredi-
6 No women ages 14–18 years were identified in the public use versions of the 2007–2008 dataset as participating in WIC. Additionally, the WIC identifier has not been released for women ages 14–18 years in the public use version of the 2009–2010 NHANES dataset.
7 The approach of the IOM (2000) was applied in which, when combining groups with different Estimated Average Requirements (EARs), intakes in one of the groups are re-scaled so that they can be compared to the EAR of the other group.
8 Nutrients of concern as listed in the 2010 DGA are vitamin D, potassium, calcium, and dietary fiber. Additional nutrients of concern for women are folate, iron, and vitamin C (for iron absorption).
ents purchased in a form allowable for other vegetables based on current regulations: fresh, frozen or canned, without added sugars, fats, or oils and dehydrated without added sugars fats, oils or sodium, as described in the Federal Register published in March 2014 (U.S. National Archives and Records Administration, 2014). Because most of the white potatoes available in frozen, canned, or dehydrated forms do not meet the requirements, if the food item was clearly identified as coming from one of these forms, the food item was considered to be in the “not WIC-eligible” form. White potatoes consumed at home but not purchased in allowable forms (e.g., potato chips) or consumed away from home in any form were categorized as not WIC-eligible white potatoes. The current intake of potentially WIC-eligible white potatoes was used as a baseline when estimating plausible scenarios for changes in intake in the sensitivity analyses.
Assessment of diet quality The diet quality of WIC participants and WIC-eligible nonparticipants was evaluated using the 2010 HEI (Guenther et al., 2013). Options for a second index were considered by the committee, based on its evaluation of the literature on existing diet quality indexes other than the HEI, and with consideration to three criteria: (1) the index can be applied to adults and children, (2) 24-hour recall data are applied, and (3) the index is based on a metric other than comparison to the DGA. After reviewing potential indexes, the committee determined that responding to the task would require an index that focuses mainly on nutrient content to provide a contrast to the food-group focus of the 2010 HEI. However, the committee found that existing nutrient-based indexes could not be applied directly for two reasons. First, they could not be applied because they use Daily Values based on a 2,000 calorie diet as reference standards for nutrient intake rather than age-appropriate DRI values. Second, they do not necessarily include all of the nutrients and dietary components the committee was interested in assessing, based on current knowledge about nutrients of concern in the diets of young children and women of childbearing age (the 2010 DGA) and the committee’s assessment of the nutrient intakes of WIC populations. The committee developed an adapted nutrient-based diet quality index to be scored by comparison to the DRI values. Given the time needed to test this index, it is not presented here and will be used in the next phases of this study.
A sensitivity analysis was conducted to project the effect of including potentially WIC-eligible white potatoes in the CVV on (1) changes in intake levels of white potatoes compared to other vegetables and fruits, (2) intakes of nutrients of concern consistent with the 2010 DGA, and (3) diet quality.
Scenarios, developed by the committee, were based on the NHANES intake data as described above, applying various ad hoc assumptions about how participants might change purchase and consumption patterns between white potatoes and other CVV eligible foods.
The “baseline” scenario is that there would be no change in white potato purchases or consumption. For the sensitivity analysis, two scenarios of increased potato consumption were modeled under a constraint to be cost neutral (a change in cost within approximately ± $0.10) and included (1) a modest increase in at-home potato consumption equal to twice the current consumption of white potatoes of a form eligible under current CVV specifications for vegetables and fruits; and (2) a large increase in at-home potato consumption equal to twice the current total consumption of white potatoes (at home plus away from home) in all forms. The goal of the sensitivity analysis scenarios was to examine reasonable changes in intake. Although adding one cup is easier to describe, it does not allow tailoring the change to be proportional to current intake of women and children. To maintain cost neutrality, two conditions were applied to compensate for each level of increase in potato consumption: (1) to offset the cost of purchasing white potatoes, purchases of other vegetables and fruits were decreased in proportion to their current intake; or (2) purchases of other vegetables only were decreased in proportion to current intake. No changes were made to consumption of food groups other than vegetables and fruits (such as grains, protein foods, or dairy). These models were tested for children and women separately. The addition of calories or fat due to butter or other toppings added to white potatoes was not evaluated. Although the committee recognized that such toppings may be added to vegetables, no data were available to determine that these additions were more likely for white potatoes than for the vegetables that they would potentially replace in the various scenarios. The WIC program is intended to facilitate acquisition of foods into the home, with nutrition education provided to encourage healthy preparation. However, within the vegetable subgroups, nutrient profiles, and thus nutrient densities, are similar so the committee did not consider the addition of toppings to white potatoes in its modeling.
Costs for each vegetable subgroup and for fruit were estimated in two ways: assuming all fresh items, and assuming a mix of fresh and canned vegetable items based on those reported to be commonly consumed by WIC participants and other low-income populations. Further details of these analyses are described in Appendix F. Outcomes evaluated under each scenario included changes in food group intakes compared to recommendations contained in the 2010 DGA, changes in nutrient intakes compared to the DRIs, and changes in dietary quality, scored by the HEI. All nutrient analyses focused on “nutrients of concern” as defined in the 2010 DGA,
namely potassium, dietary fiber, calcium, and vitamin D for the general population, and folate, iron, and vitamin C for women capable of becoming pregnant, pregnant, or breastfeeding (USDA/HHS, 2010a).
Findings and conclusions of the committee are summarized below, organized by tasks provided by the sponsor for committee consideration.
Task 1: Compare white potato consumption among the population subgroups of interest before and after the enactment of regulations in 2009, finalized in 2014, to exclude white potatoes from the WIC food packages.
Purchasing Patterns for White Potatoes
In reviewing the literature, the committee identified studies indicating that changes in vegetable and fruit purchase patterns after the CVV implementation may vary geographically. In Andreyeva and Luedicke’s (2014) study of 2,137 WIC-participating households in New England, examination of scanner data of grocery store purchases demonstrated increased purchasing of vegetables and fruits by 17.5 percent and 27.8 percent, respectively, following the change to the new WIC food package. Conversely, Gleason and Pooler (2011) found that the proportion of families in Wisconsin purchasing vegetables decreased from 63.2 percent to 59.9 percent, while the proportion purchasing fruit remained the same. However, none of the available studies included information on white potato purchases in conjunction with the CVV.
The committee reviewed studies describing purchasing patterns that occur when supplemental funds are provided for vegetables and fruits. Chiasson et al. (2013) found that vegetable consumption increased 3.5 percent among children 1 to 4 years of age, when comparing a 5-month period before the package change to a 5-month period in 2011. In one study conducted before implementation of the CVV, women enrolled in a California WIC program that were provided $40 monthly as a vegetable and fruit voucher most frequently purchased carrots, tomatoes, lettuce, broccoli, and potatoes, respectively, of vegetables (Herman et al., 2006). Potatoes made up approximately 10 percent of total supermarket purchases of fresh vegetables. Overall, vegetable and fruit intake increased as a result of the intervention (Herman et al., 2006). This study suggests that if white potatoes were not excluded from the voucher, they would likely be among the top 10 most frequently purchased vegetables. Inasmuch as the voucher in this study was four times that provided to women in the WIC CVV, it is
difficult to estimate how these findings would translate to the current $10 and $8 CVV for women and children participants, respectively.
The committee was unable to identify studies indicating specifically how WIC households would change their use of the CVV if white potatoes could be purchased. However, given a set amount for the CVV, if WIC participants bought more fresh white potatoes with the CVV, they would likely spend less on other fresh produce. USDA ERS reports estimate that fresh white potatoes, which the NHANES analysis suggests are the most commonly consumed form of potato at home by WIC participants, are among the least expensive when compared to other vegetables and fruits permitted for purchase with the CVV (USDA/ERS, 2011a). Liebtag and Kumcu (USDA/ERS, 2011b) reported that vegetable and fruit prices vary regionally, which limits the ability to predict the effect of changes in use of the CVV nationally.
Finding The literature review indicated that insufficient evidence is available to support that including white potatoes in the CVV will alter purchasing patterns. There is some evidence that provision of fruit and vegetable benefits in the revised WIC food packages increased overall purchases of vegetables and fruits among households participating in WIC in New England. The committee did not find sufficient evidence on purchasing behavior of WIC participants to determine whether white potatoes would displace currently available vegetables and fruits or white potatoes currently purchased with other funds if permitted for purchase with the CVV. Compared to all other vegetables and fruits permitted for purchase with the CVV, fresh white potatoes are among the least expensive per serving, thus their purchase with the CVV may have only a minimal effect on the purchase of other vegetables and fruits purchased with the voucher.
National Trends in Potato Production, Use, and Consumption
The committee examined long-term potato availability data (as a proxy for consumption) to understand fluctuations in demand that may have occurred relative to the 2009 exclusion regulation. In 2012, total U.S. potato production was 38 billion pounds, down from a high of more than 40 billion pounds produced in 1996 (USDA/ERS, 2014a). During the same period, exports increased steadily while per capita availability (fresh weight equivalent) fell from a high of nearly 145 pounds in 1996 to a low of 110 pounds in 2011 (USDA/ERS, 2014a). Although per capita production of white potatoes is now nearly the same as it was in 1980, product use has changed. In 1980, 63.6 pounds of white potatoes per capita were used for processed foods (e.g., frozen form, primarily french fries, potato chips,
dehydrated form, and canned), while 51.1 pounds per capita were used as table stock or “fresh.” Preliminary data indicate that in 2013, processed uses increased to 80.6 pounds per capita, while table stock uses declined to 36.1 pounds (USDA/ERS, 2014b). The shift in production from the fresh market into processed potato products is likely attributable to changes in consumer preferences, changes in retail markets including food service, and processing technologies (Richards et al., 1997; USDA/ERS, 1997).
The USDA’s Loss-Adjusted Food Availability Data Series provides an estimate of food available for consumption, after adjustment for losses in the system due to spoilage, removal of inedible components in processing, and other waste (USDA/ERS, 2014a). It is a useful measure of trends in consumption over time, both in aggregate as well as per capita basis, and converted into units equivalent to measures used in the DGA. Since 1970, consumption of all vegetables has been increasing (measured in terms of loss-adjusted availability per week), reaching 12.4 cup-equivalents per capita per week during the 1990s (calculated on a weekly basis from the Loss-Adjusted data series). By 2012, however, consumption had fallen by about 1 cup-equivalent per capita per week to 11.4 cup-equivalents.
Overall, consumption of starchy vegetables has fallen, especially since the mid-1990s. In 2012, total potato consumption represented more than one-third of the total loss-adjusted vegetable availability. Consumption of total white potatoes fell from more than 5 cup-equivalents per capita per week in 1996 to 4.3 cup-equivalents per capita per week in 2012. During the same period, consumption of fresh white potatoes dropped from more than 2 cup-equivalents per capita per week in 1996 to just more than 1.5 cup-equivalents per capita per week in 2012. The amount of potatoes consumed in other forms (chips, frozen products, canned and dehydrated potatoes) has remained nearly steady in the same period (USDA/ERS, 2014a).
Finding Although there has been a long-term decrease in loss-adjusted availability of fresh white potatoes (used for all forms of potentially WIC-eligible white potatoes) per capita, beginning well before the 2009 WIC food package changes, the committee was not able to identify changes in the availability of white potatoes in potentially WIC-eligible forms (i.e., fresh, canned, or frozen without added fat or added sugars), compared to non-WIC-eligible forms (e.g., chips, fries) nor to identify any change in potato consumption in response to the 2009 introduction of the CVV that excluded white potatoes from purchase. There is no evidence to show that the introduction of the CVV to WIC has had an effect on overall demand for white potatoes.
National Survey Data on White Potato Consumption
A direct comparison of vegetable or fruit consumption before and after the 2009 exclusion of white potatoes from the CVV was not possible using the available NHANES datasets. Although the 2009–2010 NHANES database captures approximately 15 months of CVV use, the committee could not determine either the date of interview for the respondent or the state of residence. This information is required to determine if the individual respondent would have received the CVV as part of the WIC benefits. In addition, changes in potato consumption between the survey years 2007–2008 and 2009–2010 were relatively small, and some of the group sample sizes were too small to make any statistical comparisons across the two sample periods.
The committee’s analysis of the food groups and subgroups from the combined 2007–2010 NHANES data included white potatoes consumed in all types of products, including those consumed in a form likely prepared at home from fresh potatoes only (i.e., not dehydrated, canned, or frozen).
Some differences were apparent between WIC and WIC-eligible populations and location of eating (see Appendix G). A relatively large share of the white potatoes consumed by WIC participants (32 percent for children and 46 percent for women) was eaten away from home. About two-thirds of the white potatoes consumed by all low-income children ages 1 year to less than 5 years were consumed at home. Among children participating in WIC, of all white potatoes consumed, 40 percent were consumed at home and in a form that was likely prepared from potentially WIC-eligible white potatoes (for this analysis, prepared at home from fresh potatoes), and 19 percent were eaten at home in the form of potato chips. Twenty-three percent of the white potatoes that these children consumed were in the form of french fries eaten away from home. In contrast to the patterns for white potatoes, consumption of almost all other starchy vegetables among the low-income WIC children (85 percent) occurred at home (see Table G-1).
Among low-income women, the patterns were similar, although compared to the children, women WIC participants consumed relatively fewer potatoes at home in comparison to WIC-eligible nonparticipants (54 percent compared to 65 percent). Among all low-income women, over half of white potatoes were consumed at home (54 percent for the women who participated in WIC). Similar to the children, more than 40 percent of all potatoes consumed by the women participating in the WIC program were consumed at home in a form that was likely prepared from fresh potatoes. Women participating in WIC consumed 26 percent of their intake of white potatoes away from home in the form of french fries or other frozen potato products (see Table G-2).
Finding Approximately 40 percent of all potatoes consumed by the WIC population are consumed at home in a form that is likely to be prepared from potentially WIC-eligible white potatoes.
Conclusion The data to conclude whether or not exclusion of white potatoes from the CVV has affected the availability of white potatoes to WIC participants were unavailable at the time of the committee’s analysis. The committee was unable to determine if the exclusion of white potatoes from purchase with the CVV had any effect on the consumption of potentially WIC-eligible forms of white potatoes by WIC participants or low-income nonparticipants. This was because the complete data from 2011–2012 NHANES survey needed for the most direct assessment of the impact of the 2009 exclusion were not available.
Task 2. Determine the nutrient intake (mean and distribution) for each nutrient for which a Dietary Reference Intake has been established.
Nutrient Intakes of WIC Populations
The committee examined the adequacy of intakes for seven nutrients that were deemed “of concern” by the 2010 DGA. Five of these nutrients have an Estimated Average Requirement (EAR),9 and thus it is possible to estimate the prevalence of dietary inadequacy. All nutrients are presented for both children and women, although vitamin C, iron, and folate are considered of concern for women only. As shown in Appendix H, dietary inadequacy was very high for vitamin D (77–87 percent) for both WIC children and children who were WIC-eligible but not participating (see Tables H-1 and H-2). Sunlight is also a source of this nutrient, but the increased risks of certain forms of cancer associated with sun exposure are well-documented (IOM, 2011a). The prevalence of calcium inadequacy among children was much lower (8–13 percent), and overall the prevalence of inadequacy was higher for WIC-eligible nonparticipating children than children participating in WIC for all nutrients of concern. The other two nutrients of concern, potassium and dietary fiber, have an Adequate Intake (AI) rather than an EAR. For children, mean intakes of both of these nutrients were well below the AI, indicating that the prevalence of inadequacy may be very
9 The EAR is the intake level expected to satisfy the needs of 50 percent of the people in that age group based on a review of the scientific literature. The AI is used when a recommended average daily intake level based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people are assumed to be adequate.
high. Although potassium intakes were higher for WIC children compared to non-WIC children, dietary fiber intakes were slightly lower. The prevalences of inadequate intakes for both WIC children and children who were WIC-eligible but not participating were very low for vitamin C (less than 1 percent) and folate (2.1–2.8 percent), and had a slightly wider range for iron (1.3–3.4 percent).
Also shown in Appendix H are nutrient intakes for WIC and WIC-eligible but nonparticipating women, as well as for a third group of women, those who reside in low-income households, but are not WIC-eligible because they are not pregnant, breastfeeding, or postpartum (see Tables H-3 through H-5). The prevalence of inadequacy was undesirably high for all nutrients with an EAR, and mean intakes of both potassium and dietary fiber were well below the respective AIs. No consistent differences in the magnitude of the inadequacies were noted across the three populations. Although the prevalence of iron inadequacy ranged from 9 percent to 20 percent across the three populations, these numbers are an underestimate of the true prevalence values for the groups that included pregnant women because it was necessary to use the much lower nonpregnant iron EAR distribution to calculate the prevalence.
The results for women should be interpreted with some caution due to the small sample sizes for WIC and WIC-eligible women (n = 96 and 51, respectively). Furthermore, because these samples include a mix of pregnant, breastfeeding, and nonpregnant/nonbreastfeeding women, it is not possible to state whether the prevalence of inadequacy is higher or lower across these three subgroups of women. Likewise, the group of low-income but WIC-ineligible women is different from the two WIC-eligible groups because none of them is pregnant, breastfeeding, or up to 6 months postpartum.
Finding The intakes of calcium, vitamin D, potassium, and fiber of low-income children fall short of current DRIs, and women’s intakes of all seven nutrients of concern (vitamin C for iron absorption, folate, vitamin D, calcium, potassium, iron, and dietary fiber) are in need of substantial improvement. Differences between WIC and WIC-eligible groups were small for both women and children, but inadequacies were consistently lower for WIC children compared to WIC-eligible but nonparticipating children for all nutrients except dietary fiber.
Nutritional Value of White Potatoes
White potatoes in potentially WIC-eligible forms do not contain any of the “food components to reduce” identified in the 2010 DGA. They do contain two “nutrients to increase,” namely potassium and dietary fiber
(USDA/HHS, 2010a). Potatoes also contain vitamin C, which is “recommended for specific population groups,” namely women capable of becoming pregnant (USDA/HHS, 2010a). In its data-gathering workshop, the committee heard evidence that because white potatoes are so widely consumed in the American diet, they can be considered a major source of dietary fiber (Slavin, 2008). Additionally, the committee was presented with evidence that white potatoes ranked higher than dark green, red-orange, and other starchy vegetables when considering nutrients available on a cost basis (Drewnowski and Rehm, 2013).
Nutrient Profile Evaluation
Public comments that were received by the committee included statements that white potatoes are of minimal nutritive value. To determine the nutritional value of white potatoes, the committee used USDA nutrient profiles to compare cup-equivalent amounts of white potatoes with other starchy vegetables as well as other WIC-eligible vegetable and fruit food groups (see Appendix I, Table I-1). The committee further compared the nutrient profile of white potatoes against the nutrients of concern as outlined in the 2010 DGA (USDA/HHS, 2010a).
Finding With the exception of vitamins C and folate, the nutrient content of vegetables and fruits within subgroups did not vary greatly. Overall, the nutrient profile of white potatoes was similar to that of other starchy vegetables. Because they are widely consumed, white potatoes provide useful quantities of potassium and fiber in the diets of Americans.
Conclusion The nutrient profile of white potatoes does not support their exclusion from the CVV, given that their nutrient content is similar to that of other starchy vegetables that are permitted for purchase with the voucher. Because white potatoes are particularly high in potassium, increased consumption may help reduce deficits of potassium in the diets of both children and women.
Task 3. Determine the mean intake (mean and distribution) for each food group and subgroup presented in the Dietary Guidelines for Americans (DGA). Compare these to the levels recommended in the DGA.
Starchy Vegetables in the Dietary Guidelines for Americans
The 2005 Committee to Review the WIC Food Packages (IOM, 2006) based its recommendation to exclude white potatoes from purchase on a
comparison of available consumption data with recommended daily food group amounts in the USDA Food Guide for consumption of starchy vegetables in the 2005 DGA (USDA/HHS, 2005a). Food intake data at that time indicated that consumption of starchy vegetables met or exceeded these suggested amounts (Briefel et al., 2004; FSRG/USDA/ARS, 1999; USDA/ARS, 1997, 2002), and showed that white potatoes were the most widely used type of vegetable (Briefel et al., 2004; Cavadini et al., 2000; FSRG/USDA/ARS, 1999; IOM, 2006; USDA/ARS, 1997, 2002).
The current committee conducted analyses on mean intakes of white potatoes and other starchy vegetables relative to the 2010 DGA (USDA/ HHS, 2010a). Starchy vegetables include corn, peas, potatoes, lima beans, and cassava; all fresh, frozen, and canned forms can contribute to meeting this recommendation. The recommendation for consumption of starchy vegetables was increased in the 2010 DGA: from 2.5 to 3.5 cup-equivalents per week (0.36 to 0.50 cup-equivalents per day) for children consuming the range of 1,200–1,400 kcal/day, and from 3.0 to 5.0 cup-equivalents per week (0.42 to 0.71 cup-equivalents per day) for adult women consuming 2,000 kcal/day (USDA/HHS, 2010a). The Dietary Guidelines Advisory Committee (DGAC) applied the USDA’s redesigned recommended food patterns in 2010, which used a food pattern modeling approach to realign the vegetable subgroups. As a result, a new vegetable subgroup was added (red-orange vegetables) and amounts of the other vegetable subgroups were either increased (starchy vegetables) or decreased (dark green vegetables, beans and peas, and “other” vegetables) (USDA/HHS, 2005b). Daily recommendations for total vegetables are currently as follows: 0.2 cups dark green vegetables, 0.2 cups of beans and peas, 0.8 cups of red and orange vegetables, 0.6 cups of “other” vegetables, and 0.7 cups of starchy vegetables, for a total consumption of 2.5 cups of vegetables daily (at a daily intake of 2,000 kcal). Evaluating 2001–2004 NHANES data, the 2010 DGA reported that “typical American diets” met 59 percent of the recommended intake of vegetables (USDA/HHS, 2010a).
Food Group Intakes Among the WIC Population
Analyses of 2007–2010 NHANES data (see Appendix G) show that WIC children were consuming, on average, 2.0 cup-equivalents/week of starchy vegetables (0.29 cup-equivalents/day × 7 days), or only 64 percent of their recommendation based on the 2010 DGA (see Table G-1). WIC women were consuming 2.8 cup-equivalents/week (0.40 cup-equivalents/ day × 7 days), or only 56 percent of their 2010 DGA recommendation (see Table G-2).
Intakes of other vegetable subgroups are even lower relative to the 2010
DGA recommendations (see Table 1).10 Dark green vegetable intakes were only 17 percent and 29 percent of recommended intakes for children and women, respectively, while red-orange vegetable intakes were 48 percent (for children) and 36 percent (for women) of recommendations. Likewise, total vegetable intakes were low, at 44 percent of recommendations for children, and 45 percent for women. Women’s total fruit intakes (including juices) were only 50 percent of the DGA recommendation, but children’s total fruit intake was 122 percent of the recommendations. The distribution of food group intakes is shown in Appendix J, Tables J-1 through J-5.
Finding WIC participants’ intakes of all of the vegetable subgroups were below recommendations, as were intakes of fruit for women participants. Intakes of starchy vegetables were closer to recommendations than intakes of the other vegetable subgroups, but were still considerably below the 2010 DGA recommendations.
Conclusion Intakes of all vegetable subgroups should be improved, including those of starchy vegetables. Because the 2010 DGA recommendations for starchy vegetable intake have increased compared to the 2005 DGA, intakes no longer meet or exceed these recommendations as was the case in the 2006 IOM report. Thus, the basis for excluding white potatoes that was used by the 2005 committee no longer applies.
Task 4. Determine the score (mean and distribution; by category and total) on at least two established indexes of overall diet quality (including the Healthy Eating Index-2010 and at least one other index).
The committee used data from NHANES 2007–2010 to estimate mean scores for the components of the HEI-2010 as well as the mean total score (see Appendix K, Table K-1). WIC children had a higher score than other low-income children not participating in WIC (52.6 and 50.3, respectively). In contrast, women participating in WIC had a mean HEI score very similar to low-income women not participating in WIC (46.6 and 46.9, respectively). The score ranged from approximately 31 to 36 for all low-income women at the 10th decile to 56 to 62 at the 90th decile (see Appendix K, Table K-2).
10 Recommended food group intakes for children were developed based on a 1,300 kcal diet weighted for 1- to < 5-year-olds per the method outlined in IOM (2011b) and as presented in Table 1 (page 33). Although under-reporting of foods is likely with 24-hour recalls for adults (Subar et al., 2003), it is unknown to what extent fruit and vegetable intake would be affected.
Finding All of the population subgroups had mean HEI-2010 scores indicating that, on average, these populations achieved approximately half of the maximum score considering 12 key recommendations in the 2010 DGAs. For women, of the four subscores for intake of vegetables and fruits, intakes of total vegetables achieved the highest value, while intakes of greens and beans (which includes dark green vegetables, mature beans, and peas) were lowest for both WIC and non-WIC women participants. For children, subscore for total fruit reached the highest value of fruit and vegetable scores. A nutrient-based score will be applied in phase I of this study.
Conclusion The overall quality of the diets of both WIC participants and WIC-eligible nonparticipants, as measured by the HEI, is in need of improvement, especially for greens and beans.
Task 5. Address the health and cultural needs of a widely diverse WIC participant population.
The addition of the CVV to the WIC food package was designed to make vegetables and fruits available to WIC participants, increase the consumption of diverse kinds of vegetables and fruits, and be culturally acceptable (IOM, 2006). By aligning the WIC food packages with the 2005 DGA, the revised food package in general, and the CVV in particular, were intended to contribute to the nutritional health of WIC participants consistent with the evidence available at the time.
White Potatoes and Health Outcomes
In its review of published literature, the 2010 DGAC report, and evidence presented in its workshop, the committee did not find any direct evidence linking consumption of white potatoes with adverse health outcomes or risk of chronic disease among WIC-eligible or low-income populations. Therefore, the committee primarily relied on evidence from general adult populations.
The committee reviewed evidence on associations between consumption of vegetables and fruits and potential health outcomes in general. The 2010 DGAC conducted a systematic review of the relationship between vegetable and fruit intake and various health outcomes in generally healthy adults (body weight, cancer, cardiovascular disease [CVD], and type 2 diabetes [T2D]) (USDA/HHS, 2010b). The evidence was rated moderate for an inverse relationship of increased fruit and vegetable intake for some cardiovascular outcomes, insufficient to assess a relationship to blood pressure or cholesterol, modest for decreased weight gain, and insufficient for
weight loss. Evidence was limited and inconsistent to suggest an association with T2D. The DGAC also noted a significant and consistently protective relationship between intake of nonstarchy vegetables and fruits and risk of all cancers, but evidence was insufficient for a relationship between starchy vegetables and site-specific cancers. In addition, the 2010 DGAC concluded that there were significant and positive associations with health outcomes linked to a minimum of five daily servings of vegetables and fruits, with additional benefits linked to more than five servings per day.
Evidence presented at the committee’s workshop indicated that consumption of potatoes could have a favorable impact on several measures of cardiovascular and metabolic health (McGill et al., 2013). Evidence was also presented indicating that potassium intake was low among particular racial and ethnic groups; for example, non-Hispanic black women consumed significantly less potassium than other women, although a relationship with cardiovascular health was not shown (Personal communciation, M. Storey, Alliance for Potato Research and Education, presented to the committee at its workshop held on October 14, 2014).
The committee considered the question of white potatoes and glycemic index (GI) because of its particular concern about the risk of diabetes mellitus (DM), including T2D or gestational diabetes mellitus (GDM) among women participating in WIC. As noted in the data-gathering workshop, white potatoes are high in starch, and their GI value11 varies based on variety and preparation from low (boiled Carisma potatoes at 53) to moderate (baked Russet potatoes at 72) to high (microwaved Russet potatoes 98). Microwaved Russet potatoes have a higher GI at 98, but Pontica potatoes have a moderate GI (79) when microwaved but a high GI (93) when baked (Personal communication, J. Slavin, University of Minnesota, presented to the committee at its workshop held on October 14, 2014). Thus, it is difficult to predict any impact of including white potatoes based on GI. The 2010 DGAC found strong evidence that there was not an association of GI with body weight or weight loss, or any cancers. There was insufficient evidence to determine a relationship between GI and CVD, but a moderate body of inconsistent evidence supporting some association of GI with T2D. The national prevalence of GDM in 2009–2010 was 9.2 percent (DeSisto et al., 2014). However, the prevalence of T2D or GDM is difficult to estimate for the WIC population at present because information on diabetes is taken at intake and may change over the course of pregnancy and participation in WIC. Based on 2014 survey results from Los Angeles County, California,
11 The glycemic index (GI) is an in vivo measure of the blood glucose response to a standard amount of carbohydrate from a food relative to a reference food (glucose or white bread). The GI value ranks foods on a scale from 0–100 according to the extent to which they raise postprandial blood glucose values; foods ranked less than 55 are considered low GI.
the prevalence of GDM is 12 percent, varying with ethnicity (from 6.6 to 17.6 percent), suggesting that prevalence in WIC participants may be higher than in the general population (Personal communication, S. Whaley, Public Health Foundation WIC Enterprises, January 12, 2015). Thus, the committee considered whether, for WIC participants with T2D or GDM, the consumption of white potatoes (in forms potentially permitted for purchase) has implications for diabetes management. Currently, two small systematic reviews support the usefulness of low GI foods in diets to manage both T2D and GDM (Ajala et al., 2013; Viana et al., 2014), but not diets restricted in energy or carbohydrate (Viana et al., 2014).
Finding The evidence reviewed indicates that consumption of vegetables and fruits (including white potatoes) may have some long-term health benefits. The committee found no direct evidence that consumption of white potatoes affects the health outcomes of WIC participants. Although the evidence was limited by the number and quality of studies, the committee found that consuming low GI foods may be useful for dietary management of GDM and T2D.
White Potatoes and Cultural Needs
WIC services are delivered in each of the 50 states, American Samoa, the District of Columbia, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands in addition to 34 Indian Tribal Organizations (USDA/FNS, 2012). Consequently, the population served by the WIC program is geographically and culturally diverse. Yet, few studies have examined cultural differences in white potato consumption or purchases among WIC participants by race/ethnic or cultural/geographic differences in use of the CVV. The committee therefore examined evidence for a relationship between the current WIC food package and increases in the purchase and consumption of both vegetables and fruits.
Several studies included subjects from culturally diverse groups. Odoms-Young et al. (2014), in a study of Hispanic and African-American WIC participants in Chicago, Illinois, found that the revised package was associated with significant increases in fruit intake only among Hispanic women and increases in the number of types of vegetables consumed only among African-American mothers and their children. Whaley et al. (2012) found small but significant increases in fruit and vegetable intake among a sample of WIC recipients (women and children), approximately 80 percent of whom were Hispanic. A study in Wisconsin found that although more than three-quarters of WIC participants used their CVVs, almost 5 percent more participants did not use any food instruments (checks or CVVs) between 1 month before to 18 months after implementation of the CVV
(Gleason and Pooler, 2011). Nonuse of the CVV was disproportionate among some WIC subpopulations. This change was seen across participant categories and racial and ethnic groups, but non-Hispanic Black and non-Hispanic American Indian/Alaska Native participants appeared more likely to use none of the checks provided (Gleason and Pooler, 2011). Reasons for nonuse were not known.
Finding Studies reviewed by the committee suggest that the evidence was insufficient to clearly quantify the effect and magnitude of food package changes among racial or ethnic groups.
Conclusion Although the GI value of foods may have implications for prenatal care in individuals with T2D or GDM, the GI value of white potatoes varies too widely to predict the effects on health if included in the CVV. Based on the limited evidence available, it is not clear that allowing the purchase of white potatoes with the CVV would affect certain WIC subpopulations compared to others. Should white potatoes be permitted, WIC participants could still purchase a wide variety of vegetables and fruits with the CVV that take into account their cultural food preferences.
Task 6. Conduct sensitivity analyses to estimate the effect of including white potatoes in the CVV in terms of (1) food group and nutrient intakes relative to the 2010 DGA (and DRIs), and (2) changes in dietary quality when fresh12 white potatoes are included in the WIC Food Package.
The committee conducted a sensitivity analysis to estimate the effect of including white potatoes in the CVV on intakes of food groups, nutrients, and the HEI. A summary of the output from this analysis is presented in Tables 2a (children) and 2b (women). As noted in the data analysis section of this letter report, four scenarios were tested for children and four for women. Appendix L provides one example scenario for children (see Table L-1a) and one example scenario for women (see Table L-2a) as well as the related nutrient calculations (see Tables L-1b and L-2b). Finally, Table L-3 in Appendix L shows the cost data used for the scenarios. Presented in Tables 2a and 2b are the results from scenarios testing modification of the intake of fresh vegetables only (not canned, frozen, or dehydrated) in response to increased potato intake. The costs of canned
12 The term “fresh” was included in this task by the sponsor of the study. Although the committee considers that potentially WIC-eligible white potatoes include all forms currently approved for other vegetables, the NHANES data used for the sensitivity analysis includes only fresh forms, as described above.
and frozen vegetables tend to be lower (see Appendix L, Table L-3), so that larger changes in the amounts of vegetables purchased were needed to maintain cost-neutrality. However, these differences had only a small effect on changes in intakes in the various scenarios.
The projected changes are small across scenarios because the CVV covers approximately 5 percent of monthly food costs for women 19 to 50 years of age based 2014 Thrifty Food Plan estimates (USDA/CNPP, 2014). Small increases in energy intake (less than 2 percent across all scenarios) were seen. In addition, although the sensitivity analyses examined a relatively large increase in daily potato consumption (doubling of total potato intake), the monthly cost of this increase was small, approximately $1.37 for children (see Table 2a) and $1.85 for women (see Table 2b). Thus, even with this extreme scenario, the percent of the CVV that would be spent on white potatoes was not large (17 percent of the $8 children’s CVV and 19 percent of the $10 women’s CVV). Tables 2a and 2b show the increases and decreases in consumption of vegetables and fruits based on a modest or a large change in potato consumption. As shown in the first two columns of Table 2a, if inclusion of white potatoes in the CVV led to a 0.09 cup-equivalent/day increase in a child’s potato consumption, this would result in a 19.7 percent increase in consumption of starchy vegetables, a 0.4–1.2 percent decrease in consumption of other vegetables subgroups and up to a 2 percent decrease in fruit consumption.
All changes in intake were determined to be cost-neutral within approximately $0.10 per month. Because fresh white potatoes (the most commonly consumed form at home) are relatively inexpensive, using the CVV to purchase 1 to 3 pounds per month has a minor effect on intakes of the other DGA food groups and subgroups. However, these sensitivity analyses rely on several ad hoc assumptions about how the purchases with the CVV would be redistributed if white potatoes were to be allowed. Owing to a lack of behavioral data on the response of WIC participants to changes in allowable vegetables and fruits with the CVV, the quality of these assumptions is unknown.
The committee also examined the potential effect of these changes in potato consumption on HEI scores. Four of the HEI subscores would be affected by changes modeled by the committee. These are total vegetables, greens plus beans, total fruit, and whole fruit. Changes in these subscores were estimated using the scenario for children that projected the effect of a moderate change in potato purchases using the CVV (0.09 cup-equivalents/ day) and assumed that intakes of purchases of both fruit and vegetables would decline to compensate for the cost of the white potatoes. With this scenario, energy intake would increase slightly (0.6 percent) and total vegetable intake would increase by about 10 percent while greens and beans would decrease by less than 1 percent and total fruit and whole fruit would
decrease by 2 percent and 4 percent, respectively. Because all of these HEI components have the same maximum score (5 points), the overall effect on the HEI is positive, but small. These relative percentages would also apply to the other sensitivity analysis scenarios.
Finding Based on several scenarios and a set of reasonable assumptions about purchase changes, projected food group and subgroup intakes, when compared to the 2010 DGA, were only slightly changed, moving women and children from below recommended intakes for starchy vegetables to closer, or slightly above the recommendation. Likewise, projected nutrient intake changes were small across the scenarios, in part because the variability in nutrient content is relatively small across all vegetable categories that are permitted for purchase.
Conclusion Various cost-neutral shifts in the intake of categories of fruits and/or vegetables to accommodate higher consumption of fresh white potatoes would not appreciably impact nutrient or food group intake, or the HEI scores, for women or children. Further, if potato consumption increases, then intakes of starchy vegetables would move closer to the 2010 DGA recommendations, although small declines in meeting recommendations for other vegetable subgroups may be seen.
Task 7. Ensure that the program can be administered effectively and efficiently across the nation in a cost-neutral manner.
Administration of the Current CVV
The committee collected information on program administration to assess the potential effect of including white potatoes in the CVV. Although various forms of vegetables and fruits are permitted at the national level (U.S. National Archives and Records Administration, 2014), state-level program administration varies. Fifteen states and 2 of 34 Indigenous Tribal Organizations (about 20 percent of all WIC agencies) allow the CVV to be used to purchase only fresh vegetables (USDA/FNS, 2011). In addition, although USDA regulations require authorized vendors to stock at least two different fruits and two different vegetables, minimum stocking requirements vary from state to state. California, for example, requires vendors to stock at least five different fruits and five different vegetables (U.S. National Archives and Records Administration, 2014). The committee identified one study indicating that, at the time of the evaluation, approximately 42 percent of vendors allowed minor substitutions for vegetables and fruits under the CVV, suggesting that white potatoes are at present, frequently inappropriately purchased (USDA/FNS, 2013).
Vendor response to past program changes was also considered. One study, presented to the committee in its workshop, found that fruit availability in stores increased following the 2009 regulation to exclude white potatoes from the CVV (Gleason, 2011), possibly due to stocking requirements. Gittelsohn et al. (2012) reported that overall, vendor response to the 2009 food packages changes were positive. Havens et al. (2012) reported that the availability of fruit but not vegetables increased after the 2009 WIC food package changes in 45 Hartford, Connecticut, certified WIC vendor corner stores. Three small, regional studies indicated that the variety of vegetables available increased in Philadelphia (Hillier et al., 2012), New Orleans (Rose et al., 2014), and across seven Illinois counties (Zenk et al., 2012). Additionally, the fact that at least three food companies created a one-pound size loaf of 100 percent whole wheat bread to match the revised WIC food package guidelines indicates that market adaptations to the WIC program have occurred in the past. Regarding administrative burden, monthly data on overall WIC program caseloads indicates no remarkable change in number of cases in the 12 months after implementation of the CVV (USDA/FNS, 2014).
Finding Overall, the committee found that vendors have been able to administer the CVV and the exclusion of white potatoes from purchase with the CVV.
WIC Participant Satisfaction with the CVV
The study by Gleason and Pooler (2011) showed high satisfaction with the CVV by WIC participants. They also found that, at 18 months after implementation, only 45 percent of children and pregnant women used the full CVV, and only 63 percent used the CVV to purchase any vegetable. Additionally, use of the full voucher varied by ethnicity, ranging from 30 percent for non-Hispanic Native Americans or Alaskan Natives to a high of 65 percent for non-Hispanic Asian and Pacific Islanders (Gleason and Pooler, 2011). Ritchie et al. (2014) reported that more than 90 percent of 2,996 participants interviewed were generally satisfied with the 2009 WIC food package revisions. No data were identified that assessed WIC participant response to exclusion of white potatoes from the CVV.
Finding Although WIC participants report satisfaction with the CVV, a significant proportion do not take full advantage of the voucher. The reasons for their failure to use the CVV fully are not currently understood.
Conclusion Exclusion of white potatoes from purchase with the CVV has not been documented as a concern among WIC participants. Based on the 2009 vendor response to food package revisions, future vendor adaptations to further revisions can be anticipated. If vendors opted to count white potatoes toward the minimum stocking requirement, this could potentially impact the variety of vegetables available to WIC participants, particularly in smaller stores and in states that have implemented the federal requirement of only two different vegetables. Because the proposed policy change results in no change in the amount of money WIC households are allotted, it would be reasonable to consider that there might be no change in their overall purchases of fruit and vegetables if there is no change in the availability of other WIC-eligible vegetables and fruits.
In response to its task, and based on its findings and conclusions, the committee offers four recommendations, considered in the context of maintaining the CVV as culturally suitable, cost-neutral, efficient for nationwide distribution, and nonburdensome to administration.
- The committee recommends that the U.S. Department of Agriculture allow white potatoes as a WIC-eligible vegetable, in forms currently permitted for other vegetables in the cash value voucher, pending changes to starchy vegetable intake recommendations in the 2015 Dietary Guidelines for Americans (DGA). If there are relevant changes in the 2015 DGA, the committee should reevaluate this recommendation.
The WIC food package must align with the current DGA, which means that the CVV must be aligned with recommended intakes of categories of vegetables and fruits. The recommendation of the report WIC Food Packages: Time for a Change (IOM, 2006) was based on the 2005 DGA. The recommendation for intake of total vegetables and starchy vegetable increased in the 2010 DGA; however, the intakes of total vegetables, starchy vegetables, and white potatoes did not change appreciably. The committee determined that inclusion of white potatoes in the CVV would not adversely affect and may slightly improve the intakes of potassium; would not adversely affect long-term health if consumed in alignment with the DGA; would offer WIC participants more choice of ways to meet their preferences for vegetable consumption or at minimum would not reduce
them; and might reduce the administrative burden for vendors by reducing restrictions for the CVV use. Nonetheless, concerns regarding effective implementation of the recommendation remain. These concerns require action to ensure that allowing purchase of white potatoes with the CVV does not (1) adversely affect achieving the Dietary Guidelines recommendation to consume a variety of vegetables and to limit intakes of saturated fat and sodium, or (2) limit the availability in other categories of vegetables offered by vendors.
- The committee recommends that the U.S. Department of Agriculture and the U.S. Department of Health and Human Services collaborate to achieve expansion of data collection on dietary intakes for pregnant, breastfeeding, and postpartum women in the National Health and Nutrition Examination Survey.
The committee’s ability to respond to the USDA’s request for specific analyses was compromised by a lack of data on dietary intake for adequate numbers of pregnant, breastfeeding, or postpartum women at any income and, especially, for low-income women in general and WIC participants in particular. These data are critical to future evaluations of changes in the WIC food packages.
- The committee recommends that the U.S. Department of Agriculture undertake a separate, comprehensive examination of currently available data to assess the effectiveness of the current cash value voucher in meeting participants’ food pattern and dietary intake goals as recommended by the Dietary Guidelines for Americans, including use of white potatoes in the context of cultural diversity among WIC participants.
The committee’s ability to respond to the USDA’s request that its recommendations be able to be “administered effectively and efficiently nationwide” was hampered by the lack of comprehensive national data on numerous aspects of the implementation of the WIC Program and, in particular, the use of the CVV.
- The committee recommends that the U.S. Department of Agriculture allocate resources to support studies related to (1) participant satisfaction with the cash value voucher (CVV); (2) the strategies participants use to decide how much of the CVV to spend; (3) the
- strategies participants use to decide how to apportion this benefit among the vegetables and fruits, between vegetables and fruits, and between the CVV and other food purchases; (4) how vendors have changed the WIC-eligible vegetables and fruits they stock because of the implementation of the CVV; and (5) how the CVV and its implementation have affected vendors.
The committee’s ability to construct a thorough, relevant, and evidence-based sensitivity analysis for this report was hampered by a lack of information about how participants have thought about and used the CVV. Moreover, the committee’s ability to understand the satisfaction of either WIC participants or vendors with the CVV or understand how either WIC participants or vendors thought about how to use the CVV was also hampered by a lack of information.
TABLE 1 Summary of Daily Food Group Recommendations and Intakes
|WIC Children (n = 643)||WIC Women (n = 96)|
|Food Group||Recommendation||Mean Intake||Percent of Recommended Intake||Recommendation||Mean Intake||Percent of Recommended Intake|
|Starchy Vegetables (c-eq/d)||0.5||0.3||64||0.7||0.4||56|
|Dark Green Vegetables (c-eq/d)||0.1||0.02||17||0.2||0.06||29|
|Red-Orange Vegetables (c-eq/d)||0.4||0.2||48||0.8||0.3||36|
|Total Vegetables (c-eq/d)||1.4||0.6||44||2.5||1.1||45|
|Protein Foods (oz-eq/d)||3.1||2.8||90||5.5||5.1||93|
NOTES: c-eq/d = cup-equivalents/d; g-eq/d = gram-equivalents/d; oz-eq/d = ounce-equivalents/d. See Appendix J for intake distributions.
DATA SOURCES: Mean intake data are from NHANES 2007–2010 for low-income individuals identified as participating in WIC: low-income children 1–4.9 years of age and women 19–50 years of age (USDA/ARS, 2007–2010). Food group intake recommendations are from the 2010 Dietary Guidelines for Americans (USDA/HHS, 2010a). Food group recommendations for children are weighted in a 1:3 ratio using 1,000 and 1,300 (averaged from 1,200 and 1,400) calorie food patterns, following the methodology applied by the IOM (2011b). Recommendations for women are for 2,000 kcal diet.
TABLE 2a Sensitivity Analysis Summary for Children Participating in WIC
|Moderate Increase in White Potatoes||Moderate Increase in White Potatoes, No Change in Fruit||Large Increase in White Potatoes||Large Increase in White Potatoes, No Change in Fruit|
|Changes from Baseline Assumptions|
|Change in white potatoes, c-eq/d||0.09||0.09||0.24||0.24|
|Cost of white potatoes, $/month||$0.51||$0.51||$1.37||$1.37|
|Increase in % of starchy veg recommended||19.7%||19.4%||52.1%||51.7%|
|Decrease in % of other 3 veg subgroups recommended||0.4–1.2%||0.8–2.3%||1.5–4.3%||2.1–5.9%|
|Decrease in % of fruit recommended||2.0%||NA||7.3%||NA|
|Results from Changes to Baseline|
|Increase in total vegetable intake, c-eq/d||0.08||0.07||0.20||0.19|
|Decrease in fruit intake (without juice), c-eq/d||0.02||NA||0.07||NA|
|% Increase in energy intake||0.6%||0.7%||1.5%||1.1%|
|% Increase in dietary fiber intake||1.5%||1.9%||3.3%||1.4%|
|% Increase in potassium intake||2.0%||2.2%||5.1%||4.1%|
|% Change in other nutrients of concern*||0–0.7%||0–0.9%||0–1.3%||0–0.9%|
NOTES: c-eq/d = cup-equivalents/d; NA = not applicable. An example of calculations for one scenario can be found in Appendix Tables L-1a and L-1b. Cost calculations are in Appendix Table L-3 and based on all fresh substitutions.
* Nutrients of concern as listed in the 2010 DGA (USDA/HHS, 2010a): calcium, iron, potassium, vitamin C, folate, vitamin D, and dietary fiber.
DATA SOURCES: NHANES 2007–2008 and NHANES 2009–2010 data for low-income children 2–5 years of age (USDA/ARS, 2007–2010). Food group recommendations per 2010 Dietary Guidelines for Americans (USDA/HHS, 2010a); nutrient intakes were compared to the RDA/AI for children 1–3 years of age and 4–8 years of age as listed in Table E-1. Food group recommendations are weighted in a 1:3 ratio using 1,000 and 1,300 (averaged from 1,200 and 1,400) calorie food patterns, following the methodology applied by the IOM (2011b). Nutrient profiles of the food subgroups are presented in Table L-1b.
TABLE 2b Sensitivity Analysis Summary for Women Participating in WIC
|Moderate Increase in White Potatoes||Moderate Increase in White Potatoes, No Change in Fruit||Large Increase in White Potatoes||Large Increase in White Potatoes, No Change in Fruit|
|Changes from Baseline Assumptions|
|Change in white potatoes, c-eq/d||0.14||0.14||0.33||0.33|
|Cost of potatoes, $/month||$0.80||$0.80||$1.85||$1.85|
|Increase in % of starchy veg recommended||19.2%||19.1%||44.5%||44.3%|
|Decrease in % of other 3 veg subgroups recommended||1.0–1.9%||1.2–2.3%||2.4–4.6%||3.0–5.8%|
|Decrease in % of Fruit Recommended||1.1%||NA||2.6%||NA|
|Results from Changes to Baseline|
|Increase in total vegetable intake, c-eq/d||0.12||0.11||0.27||0.25|
|Decrease in fruit intake (without juice), c-eq/d||0.02||NA||0.05||NA|
|% Increase in energy intake||0.7%||0.8%||1.7%||1.9%|
|% Increase in dietary fiber intake||1.9%||2.0%||4.0%||4.6%|
|% Increase in potassium intake||2.7%||2.9%||6.5%||6.7%|
|% Change in other nutrients of concern*||0–1.1%||0–1.3%||0–2.6%||0–3.0%|
NOTES: c-eq/d = cup-equivalents/d; NA = not applicable. An example of calculations for one scenario can be found in Appendix Tables L-2a and L-2b. Cost calculations are in Appendix Table L-3 and based on all fresh substitutions.
* Nutrients of concern as listed in the 2010 DGA (USDA/HHS, 2010a): calcium, iron, potassium, vitamin C, folate, vitamin D, and dietary fiber.
DATA SOURCES: NHANES 2007–2008 and NHANES 2009–2010 data for WIC women 19–50 years of age (USDA/ARS, 2007–2010). Food group recommendations per 2010 Dietary Guidelines for Americans (USDA/HHS, 2010); nutrient intakes were compared to the RDA/AI for women 19–50 years of age as listed in Table E-1. Nutrient profiles of the food subgroups are presented in Table L-1b.
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