Good nutrition is an essential part of healthy childhood.

Transcription

1 Current Research Nutritional Quality of the Diets of US Public School Children and the Role of the School Meal Programs MELISSA A. CLARK, PhD; MARY KAY FOX, MEd RESEARCH ABSTRACT Background Good nutrition is essential to healthy childhood. Because the school meal programs the National School Lunch Program and the School Breakfast Program are so widely available, they are in a unique position to influence the nutritional quality of children s diets. Objective This article assesses the nutritional quality of the diets of US public school children and explores the relationship between children s participation in the school meal programs and the nutritional quality of their diets. Design Data were collected as part of the third School Nutrition Dietary Assessment Study (SNDA-III), a nationally representative study fielded during school year Data on children s dietary intakes were collected through in-person 24-hour dietary recalls. Nutritional quality of children s diets was assessed by estimating the prevalence of inadequate and excessive intakes of energy and nutrients. Subjects/setting The analysis is based on a nationally representative sample of 2,314 children in grades 1 through 12 from 287 public schools. Statistical analyses performed Nutrient adequacy and excess were assessed by comparing usual nutrient intake distributions to Dietary Reference Intakes and the Dietary Guidelines for Americans Propensity score matching was used to examine the relationship between school meal program participation and the prevalence of inadequate and excessive intakes. M. A. Clark is a senior researcher, Mathematica Policy Research, Inc, Princeton, NJ. M. K. Fox is a senior researcher, Mathematica Policy Research, Inc, Cambridge, MA. STATEMENT OF CONFLICT OF INTEREST: See page S55. Address correspondence to: Melissa A. Clark, PhD, Mathematica Policy Research, Inc, PO Box 2393, Princeton, NJ MClark@Mathematicampr.com Address reprint requests to: Jackie Allen, Mathematica Policy Research, Inc, PO Box 2393, Princeton, NJ jallen@mathematica-mpr.com Published by Elsevier Inc. on behalf of the American Dietetic Association /09/ $0.00/0 doi: /j.jada Results The majority of public school children in the United States had nutritionally adequate diets, but 80% had excessive intakes of saturated fat and 92% had excessive intakes of sodium. School meal program participation was associated with reduced prevalence of nutrient inadequacy but with increased prevalence of excessive sodium intakes. Conclusions School meal programs play an important role in the nutritional adequacy of children s diets. However, the association between program participation and excessive sodium intakes, along with the high prevalence of excessive saturated fat intakes among all students, suggest areas for improvement in the meals these programs provide. J Am Diet Assoc. 2009;109:S44-S56. Good nutrition is an essential part of healthy childhood. However, national survey data show that some children do not get enough of the vitamins and minerals needed to maintain health and support growth and development (1). Moreover, poor diet and physical inactivity, which may lead to an energy imbalance, are major contributors to the alarming increases in childhood obesity seen in the United States during the past 2 decades (2). Because of their widespread availability, the school meal programs the National School Lunch Program (NSLP) and the School Breakfast Program (SBP) are in a unique position to influence the nutritional quality of children s diets. On an average school day, more than 30 million children eat a school lunch and more than 10 million eat a school breakfast (3). The first School Nutrition Dietary Assessment Study (SNDA-I), conducted in school year , found that children s average daily intakes of most vitamins and minerals met or exceeded the Recommended Dietary Allowances, but that average energy intakes as well as intakes of fat, saturated fat, and sodium exceeded recommended levels (4,5). In addition, SNDA-I found participation in the NSLP to be associated with increased intakes of several key nutrients, but also to be associated with increased intakes of fat, saturated fat, and sodium. Since SNDA-I, the Food and Nutrition Service of the US Department of Agriculture (USDA), which administers the school meal programs, has launched a number of initiatives to improve the quality of school meals (6). The second SNDA study (SNDA-II), conducted in school year , found that the fat and saturated fat content of the average school lunch had decreased since school year S44 Supplement to the Journal of the AMERICAN DIETETIC ASSOCIATION

2 (ie, SNDA-I) without sacrifice of vitamin and mineral content, but that there was still room for improvement (7). Moshfegh and colleagues (1) used data from the National Health and Nutrition Examination Survey to assess dietary intakes of the US population and found that the majority of school-aged children had adequate usual intakes of most key nutrients but excessive intakes of sodium. Female adolescents aged 9 to 18 years had inadequate intakes of several nutrients, including vitamins A, C, and E; folate; magnesium; and phosphorus (1). Devaney and colleagues (8) analyzed data from the and 1998 Continuing Survey of Food Intakes by Individuals (CSFII) and reported similar findings (8). They also found that about a quarter of female adolescents had usual fat intakes that exceeded the Acceptable Macronutrient Distribution Range (AMDR) defined in the Dietary Reference Intakes (DRIs). Gleason and Suitor (9,10) assessed the quality of children s diets and the association between school meal participation and diet quality using data from the CSFII. They found that participation was associated with increased intakes of several vitamins and minerals but also with increased intakes of fat. However, the CSFII data were collected in the early stages of a major national initiative to improve school meals and may not reflect the changes observed in the quality of school meals since SNDA-I. This article uses data from SNDA-III to assess the nutritional quality of the diets of US public school children and to explore the relationship between children s participation in the school meal programs and the nutritional quality of their diets. SNDA-III data have an important advantage over the CSFII and National Health and Nutrition Examination Survey data, in that estimates of the nutrient content of foods consumed in NSLP and SBP meals are based on school menu and recipe data rather than solely on children s descriptions of foods consumed. Thus, the SNDA-III data provide a more accurate picture of children s usual nutrient intakes on school days. The analyses address two specific research questions: What is the nutritional quality of the diets of US public school children, as measured by the prevalence of inadequate and excessive usual intakes of energy and nutrients? And what is the relationship between children s participation in the school meal programs and the nutritional quality of their diets? METHODS Sample Design SNDA-III was based on a nationally representative sample of public school children in grades 1 through 12. The study s multistage sampling approach first sampled school food authorities, then schools served by these school food authorities, and then children who attended these schools. Children were randomly sampled, from lists of all children enrolled at the sampled school, to complete a 24-hour dietary recall and child interview. Parents of all sampled children were asked to complete a parent interview. The analysis sample for this article comprises all children who completed a dietary recall and whose parent completed a parent interview 2,314 children in 287 schools in 94 school food authorities. The response rate for the 24-hour dietary recalls and child interviews was 63%, given that the school was participating in the study. The response rate for the parent interview, given that the child had completed the in-school dietary recall and child interview, was 89%. Approximately 35% of children in the analysis sample were randomly selected to complete a second 24-hour recall 666 (29%) children in the analysis sample completed these second 24-hour recalls. Data from the second 24-hour recalls were used, in conjunction with data from the full sample of 2,314 children with first 24-hour recalls, to estimate usual energy and nutrient intakes (11). Additional details about the SNDA-III sample are provided by Gordon and colleagues (12). Data Collection All data collection instruments and procedures were reviewed and approved by the Food and Nutrition Service of the USDA, the 2004 Education Information Advisory Committee of the Council of Chief State School Officers, and the Office of Management and Budget. In addition, the study worked with any institutional review process a school district required. Depending on school district requirements, active or passive consent forms were used to obtain informed consent from parents or guardians of children to be interviewed. Dietary recalls were collected between January and June 2005, with a modified version of the Automated Multiple Pass Method software (version 2.3, 2003, Agricultural Research Service, Food Surveys Research Group, Beltsville, MD). Children in middle and high schools were interviewed in the morning and reported the previous day s intake (from midnight to midnight). Because young children tend to have difficulty recalling their intake, children in elementary schools were interviewed in two parts and with parental assistance. These children were first interviewed during the school day, after lunch if possible, and were asked to report everything they had consumed that day since awakening. They were then interviewed a second time to report intake for the rest of the 24-hour period. These second interviews were conducted the next day if possible, and were conducted no more than 48 hours after the first interview. Parents attended the second in-person interviews and were asked to help their children recall and describe the foods and beverages consumed. In addition to information on the types and quantities of food and beverages consumed, the dietary recalls collected data on the time each item was consumed, the reported eating occasion (eg, breakfast, brunch, lunch, supper, dinner, or snack), and where each item was obtained. For items obtained at school, children were asked to identify a specific location from which the items were obtained (eg, a specific cafeteria line, vending machine, snack window or cart, canteen, or school store). Data on intake of dietary supplements were not collected. The child and parent interviews collected information on demographics and eating habits. The child interview consisted of questions pertaining to eating habits, attitudes toward school meals, school meal participation, and activity levels. The parent interview consisted of questions pertaining to the child s health, eating habits and activity levels, parent s attitudes toward school meals, February 2009 Supplement to the Journal of the AMERICAN DIETETIC ASSOCIATION S45

3 and household demographics and food security. Data from the child and parent interviews were used in the propensity score matching procedure. Data Preparation USDA s SurveyNet coding system (version 3.14, 2004, USDA Agricultural Research Service, Beltsville, MD) was used to link each item reported in the 24-hour recalls to the Food and Nutrient Database for Dietary Studies (version 1.0, 2004, USDA Agricultural Research Service Food Surveys Research Group, Beltsville, MD). Subsequently, for foods and beverages that were obtained at school from reimbursable meal sources and were reported on school menus, nutrient values from the Food and Nutrient Database for Dietary Studies were replaced with nutrient values from the analysis of school menus (13). This step ensured that NSLP and SBP foods were represented in the analysis as accurately as possible. For example, rather than hamburgers or cheese pizzas obtained at school being consistently represented by the default values available in the nutrient database, the nutrient value of the hamburgers and pizzas actually served in each child s school were used. Thus, if a school purchased extra-lean hamburger patties or pizzas made with less or low-fat cheese, this was reflected in the 24-hour recall data. Automated checks built into the Automated Multiple Pass Method and SurveyNet systems helped ensure data quality and consistency. In addition, data were checked for extreme nutrient values that may have resulted from entry errors, and results were reviewed by coding supervisors. Data were recoded only when there was an obvious coding error or when the reported value was clearly implausible. ANALYTIC METHODS Definition of School Meal Program Participation To determine whether a child participated in the NSLP or SBP on the day referenced in the 24-hour recall, information on the foods reported by children was combined with information from the school menus and children s selfreports of whether they ate a regular school lunch that day. (Children were not asked whether they ate a regular school breakfast. ) Because of differences in mealplanning requirements, the definition of school meal participation differed slightly depending on whether the school used food-based menu planning or Nutrient Standard Menu Planning (see Crepinsek and colleagues [13]). In schools with food-based menu-planning systems, children were counted as NSLP participants if they reported consuming at least three of the five required food items (ie, one grain, one meat/meat alternate, two fruits and/or vegetables, one milk) for lunch, and all three were obtained from the school cafeteria and were on the school menu or if they reported consuming at least one of the five required food items, and the item was obtained from the cafeteria and was on the school menu, and also reported consuming a regular school lunch that day. In Nutrient Standard Menu Planning schools, children were counted as NSLP participants if they reported consuming at least one entrée and one side for lunch and both were obtained from the cafeteria and were on the school menu, or if they reported consuming at least one entrée or side obtained from the cafeteria that was on the school menu and also reported consuming a regular school lunch that day. Similar rules were used to define SBP participants. In schools with food-based menu planning, children were classified as SBP participants if they reported consuming at least one of the four required food items for breakfast (ie, two grains or two meat/meat alternates, one fruit or vegetable, one milk), and this item was obtained from the cafeteria and was on the school menu. In Nutrient Standard Menu Planning schools, children were counted as SBP participants if they reported consuming at least one required item for breakfast (including milk) that was obtained from the cafeteria and was on the school menu. All children who were not defined as participants were instead classified as ; these children may have obtained their meal from home or some other source outside the school or from some nonreimbursable source within the school (such as a vending machine or à la carte line), or they may have skipped the meal entirely. Estimating Usual Nutrient Intake Distributions The types and amounts of food and beverages a person consumes vary from day to day. The SNDA-III 24-hour dietary recalls collected data on intakes on a single day, but the DRIs are based on usual intakes rather than intakes on a single day. To account for day-to-day variation in estimating children s usual nutrient intakes, the personal computer version of the Software for Intake Distribution Estimation (version 1.0, 2003, Iowa State University, Ames) was used. Using the single 24-hour recall collected for all 2,314 children and the second recall collected for the subsample of 666 children, this program applied methods developed by Nusser and colleagues (14) to estimate usual nutrient intake distributions, as well as the proportion of individuals with usual intakes above or below user-defined cutoff values. Estimating the Prevalence of Adequate and Excessive Nutrient Intakes The nutritional quality of children s diets was assessed by estimating the prevalence of inadequate and excessive usual nutrient intakes. To do so, the distribution of children s usual intakes was compared to the DRIs, following the procedures recommended by the Institute of Medicine (11). For most vitamins and minerals with an Estimated Average Requirement (EAR), the EAR cut-point method was used to estimate the percentage of the population with adequate intakes (11,15). For iron, because the distribution of requirements is not symmetrical for menstruating women, the probability approach the Institute of Medicine recommends for estimating the prevalence of adequate intakes was used (11). EARs have not been defined for calcium, potassium, and fiber, so it was not possible to assess the prevalence of adequate intakes. Instead, mean usual intakes were compared to Adequate Intakes (AIs). Subgroups with mean usual intakes at or above the AI can be assumed to have diets that are nutritionally adequate; however, no firm conclusions can be drawn about nutritional adequacy when mean usual S46 February 2009 Suppl 1 Volume 109 Number 2

4 intakes are less than the AI (11). For sodium, usual intakes were compared to the Tolerable Upper Intake Level (UL) to estimate the percentage of children with excessive intakes. For total fat, carbohydrate, and protein, usual intake distributions, expressed as a percentage of energy intake, were compared to AMDRs to estimate the percentage of children with usual intakes within the AMDR as well as the percentage with usual intakes less than and greater than the AMDR. For saturated fat and cholesterol, DRIs are not defined, because no minimum intake level is recommended. Therefore, usual intakes of these dietary components were compared to the recommendations in the Dietary Guidelines for Americans 2005 (16). Usual intakes that exceeded these recommendations were deemed to be excessive. Because DRIs vary by age and sex, the subgroups used in the analyses (ie, elementary, middle, and high school aged children) spanned multiple DRI categories. To assess the prevalence of adequate and excessive intakes in these combined subgroups, each child s observed intake was divided by the appropriate standard and then the resulting ratio was adjusted using the personal computer version of the Software for Intake Distribution Estimation to estimate the distribution of usual intake-to-standard ratios. The percentage of the group with ratios less than one was then calculated this yielded an estimate of the percentage of children with usual intakes above or below the DRI standard for the combined group. For energy, the DRIs specify an Estimated Energy Requirement (EER), which varies according to age, sex, weight, height, and activity level. Because populations in balance should have roughly equivalent distributions for usual energy intake and EERs, the assessment of energy intake focused on comparing means and distributions of usual energy intakes and EERs. EERs were computed for all sample members who had reliable data on height and weight. Children were assumed to have a low active level of physical activity for these computations, because physical activity was not directly measured in SNDA-III. Assessing the Role of the School Meal Programs in Children s Usual Nutrient Intakes Children who participate in the NSLP or SBP are likely to differ from in many ways, both observable and unobservable. For example, participants in both programs are, on average, younger, lower-income, and more likely to be boys than (17). can also differ from in unobservable ways for example, they may have different attitudes about healthful eating or different preferences for particular foods. Because of observed and unobserved differences between the two groups of children, their dietary intakes might differ even if the school meal programs were not available and participants obtained their meals from other sources. Propensity-score matching was used to adjust for some of the observable differences between school meal program participants and (18-20). This approach is similar to a multivariate regression in that it attempts to adjust for differences in observable characteristics, but unlike multivariate regression it can be used in conjunction with the Institute of Medicine procedure for estimating usual intake distributions, which is implemented at the group rather than the individual level. Under the propensity-score matching approach, school meal program participants were matched to based on similarities in observable characteristics. Specifically, a logit model of school meal program (ie, NSLP or SBP) participation was estimated as a function of each child s age, sex, race, ethnicity, and height; parent reports of whether the child was a hearty or picky eater, the child s health, whether or not the child was on a diet, family income, and language spoken at home; and school location (ie, urbanicity and geographic region). The results of this model were used to estimate a propensity score reflecting the likelihood that a given child participated in the NSLP or SBP. This score was then used to match each participant with a nonparticipant with a similar combination of characteristics by selecting the nonparticipant with the most similar value of the propensity score (the nearest neighbor matching method [19]). Usual nutrient intake distributions for participants and the matched sample of were estimated and compared to them to the DRI standards as described above. Although the propensity-score matching procedure adjusts for differences in observable characteristics of school meal participants and, there may still be many unobserved differences between the two groups not accounted for by the procedure, so estimated differences in the dietary intakes of participants and matched cannot be interpreted as causal effects of the school meal programs. Additional information about the propensity-score matching procedure is available in the SNDA-III final report (17). Statistical Methods All analyses presented in this paper are weighted so the sample is representative of public school children nationwide. The final weights adjust both for unequal probabilities of selection at each stage of sampling and for nonresponse at each stage of data collection. Standard error estimates account for the complex sampling design. Two-tailed t tests were used to test the statistical significance of differences in intakes of school meal program participants and matched, and differences were flagged if statistically significant at the 5% or 1% levels. However, the relatively small sample sizes for the propensity score matching analysis of SBP participants and (381 participants and 302 matched ) and the relatively small sample sizes for grade-level subgroups provided limited statistical power to detect significant differences between participants and. As a result, in some cases patterns of substantive differences between the two groups are discussed, even though some of these differences are not statistically significant at the 5% level. RESULTS Usual Energy and Nutrient Intakes of School-Aged Children Table 1 presents estimates of mean 24-hour energy and nutrient intakes of school-aged children, overall and by February 2009 Supplement to the Journal of the AMERICAN DIETETIC ASSOCIATION S47

5 Table 1. Mean 24-hour energy and nutrient intakes of elementary, middle, and high school children attending public schools a Nutrient All children (n 2,314) Elementary school children (n 732) Middle school children (n 787) High school children (n 795) 4 % standard error 3 Energy (kcal) Food energy 2, , , , Macronutrients (% of food energy) Total fat Saturated fat Carbohydrate Protein Vitamins Vitamin A ( g RAE b ) Vitamin C (mg) Vitamin E (mg) Vitamin B-6 (mg) Vitamin B-12 ( g) Folate ( g DFE c ) Niacin (mg) Riboflavin (mg) Thiamin (mg) Minerals Calcium (mg) 1, , , , Iron (mg) Magnesium (mg) Phosphorus (mg) 1, , , , Potassium (mg) 2, , , , Sodium (mg) 3, , , , Zinc (mg) Other dietary components Fiber (g) Fiber (g/1,000 kcal) Cholesterol (mg) a Data are from the third School Nutrition Dietary Assessment Study, 24-hour dietary recalls, school year Tabulations are based on first 24-hour recall and weighted to be nationally representative of children in public National School Lunch Program schools. Sample sizes are unweighted. b RAE retinol activity equivalents. c DFE dietary folate equivalents. school type. Table 2 presents estimates of the prevalence of nutrient inadequacy and excess and comparisons of reported energy intakes with EERs. Overall, mean energy intakes exceeded mean EERs by about 70 kcal per day, but the differences varied by school type. Among elementary school children, mean energy intake exceeded the mean EER by 310 kcal. The relationship was reversed among middle and high school aged children, with mean EERs exceeding mean energy intakes by 170 to 190 kcal. At both the middle and high school levels, mean EERs exceeded mean energy intakes for both male and female adolescents (Table 3). Macronutrients. The AMDR for fat is 25% to 35% of total energy intake. Close to 80% of all school-aged children had usual fat intakes within this range (Table 2). Children with usual fat intakes inconsistent with the AMDR were more likely to have exceeded the upper end of the range than to have fallen below the lower end. The prevalence of fat intakes exceeding the AMDR was notably higher among high school aged children than among elementary or middle school children. The 2005 Dietary Guidelines recommend that saturated fat account for 10% of total energy; the vast majority of school-aged children had usual intakes of saturated fat that exceeded this recommendation. Children s usual carbohydrate and protein intakes were generally consistent with the respective AMDRs, and inadequate intakes (usual intakes below the EAR) of carbohydrate were rare. Inadequate protein intakes were rare at the elementary school level and among male adolescents at the middle and high school levels (Table 3). However, 12% of female middle school students and 17% of female students had inadequate protein intakes, based on grams of protein consumed per kilogram body weight. Vitamins and Minerals with EARs. In general, the prevalence of inadequate intakes of vitamins and minerals was low ( 3%) for school-aged children (Table 2). The prevalence of inadequacy was 15% or higher for vitamin A, vitamin C, vitamin E, magnesium, phosphorous, and zinc. For almost all vitamins and minerals examined, the prevalence of inadequate intakes was lowest among elementary school children and highest among high school aged S48 February 2009 Suppl 1 Volume 109 Number 2

6 Table 2. Percentage of public school children in elementary, middle, and high school with acceptable, inadequate, or excessive usual daily intakes ab Dietary component All children (n 2,314) Elementary school children (n 732) Middle school children (n 787) High school children (n 795) 4 mean standard error 3 Energy Intake (kcal) 2, , , , Estimated Energy Requirement (kcal) 2, , , , Macronutrients total fat % within AMDR c 78.6 NA d 85.1 NA 91.2 NA 64.6 NA % AMDR e e % AMDR 3 e e e e 3.15 Saturated fat % DGA f Carbohydrate % EAR g 3 e e NA 3 e e 0.35 % within AMDR 97 NA 97 NA 97 NA 90.4 NA % AMDR 3 e e e NA 3 e 2.35 % AMDR 3 e e e e 4.68 Protein % EAR e NA 4.8 e % within AMDR 97 NA 97 NA 97 NA 97 NA % AMDR 3 e NA 3 e NA 3 e NA 3 e NA % AMDR 3 e e e e 2.42 Vitamins and minerals with EARs (% <EAR) Vitamin A e Vitamin C h e Vitamin E Vitamin B e e e e 3.89 Vitamin B-12 3 e e e e 2.78 Folate e e e 3.94 Niacin (mg) i 3 e e e e 2.16 Riboflavin (mg) e e e 1.74 Thiamin (mg) e e Iron (mg) j 3.7 NA 3 NA 3 NA 10.0 NA Magnesium (mg) e Phosphorus (mg) Zinc (mg) e e Calcium, potassium, and sodium Calcium (mean % AI) k Potassium (mean % AI) Sodium (% Tolerable Upper Intake Level) Other dietary components Fiber (mean % AI) Cholesterol (% DGA) e e a Data are from the third School Nutrition Dietary Assessment Study, 24-hour dietary recalls, school year Tabulations are based on first and second 24-hour recalls and weighted to be nationally representative of children in public National School Lunch Program schools. Sample sizes are unweighted. b Usual intake distributions were determined for each subgroup using the PC version of the Software for Intake Distribution Estimation (version 1.0, 2003, Iowa State University, Ames). Sample includes all children, including those who did not consume a lunch. c AMDR Acceptable Macronutrient Distribution Range. d NA not available. Standard error could not be estimated for percentages very close to 0 or 100 or for percent with AMDR. e Statistic is potentially unreliable due to a small sample size and/or a coefficient of variation 30%. f DGA Dietary Guidelines for Americans 2005 recommendation (16). g EAR Estimated Average Requirement. h The EAR for vitamin C is 35 mg greater for smokers than nonsmokers. These tabulations used EARs for nonsmokers. i Niacin intakes include preformed niacin only. EARs for niacin are expressed as niacin equivalents, including contributions from tryptophan. Therefore, prevalence of inadequate niacin intakes may be overestimated. j Comparison to EAR was done using the probability approach. Standard errors were not estimated, and the significance of differences between participants and was not tested. k AI Adequate Intake. February 2009 Supplement to the Journal of the AMERICAN DIETETIC ASSOCIATION S49

7 S50 February 2009 Suppl 1 Volume 109 Number 2 Table 3. Percentage of public school children with acceptable, inadequate, or excessive usual daily intakes, by sex ab Dietary component All (n 1,143) Elementary school (n 372) Male Children Middle school (n 386) High school (n 385) All (n 1,171) Elementary school (n 360) Female Children Middle school (n 401) High school (n 410) 4 mean standard error 3 Energy Intake (kcal) 2, , , , , , , , Estimated Energy Requirement (kcal) 2, , , , , , , , Macronutrient Total fat % within AMDR c 97 NA d 90.9 NA 91.5 NA 79.5 NA 71.0 NA 83.0 NA 78.7 NA 57.4 NA % AMDR 3 e NA 8.6 e e e e e % AMDR 3 e NA 3 e NA 3 e NA 3 e NA 6.6 e e e NA 10.5 e 4.23 Saturated fat % DGA f e Carbohydrate % EAR g 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA % within AMDR 97 NA 97 NA 97 NA 97 NA 93.8 NA 97 NA 96.1 NA 85.8 NA % AMDR 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 5.5 e 4.43 % AMDR 3 e NA 3 e NA 3 e NA 3 e NA 3.9 e e NA 3 e NA 8.6 e 5.38 Protein % EAR 3 e NA 3 e NA 3 e NA 3 e NA e NA 11.8 e % within AMDR 97 NA 97 NA 97 NA 97 NA 97 NA 97 NA 97 NA 97 NA % AMDR 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA % AMDR 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA 3 e NA Vitamins and minerals with EARs (% <EAR) Vitamin A e e Vitamin C h e e e e NA Vitamin E e Vitamin B-6 3 e NA 3 e NA 3 e NA 3 e NA e NA 12.3 e Vitamin B-12 3 e NA 3 e NA 3 e NA 3 e NA 4.4 e e NA e 4.79 Folate 3 e NA 3 e NA 3 e NA 3 e NA e NA Niacin (mg) i 3 e NA 3 e NA 3 e NA 3 e NA 3.3 e e NA 5.6 e e 4.10 Riboflavin (mg) 3 e NA 3 e NA 3 e NA 3 e NA e NA 4.3 e e 3.02 Thiamin (mg) 3 e NA 3 e NA 3 e NA 3 e NA e NA 9.9 e Iron (mg) j 3 e NA 3 e NA 3 e NA 3 e NA 7.2 NA 3 NA 5.7 NA 19.1 NA Magnesium (mg) e e Phosphorus (mg) e e e e Zinc (mg) 3.2 e e NA 3.2 e e e e Sodium and cholesterol Sodium (% Tolerable Upper Intake Level) 97 NA 97 e NA 97 e NA e Cholesterol (% DGA) 12.2 e e e e e e e 4.4 a Data are from the third School Nutrition Dietary Assessment Study, 24-hour dietary recalls, school year Tabulations are based on first and second 24-hour recalls and weighted to be nationally representative of children in public National School Lunch Program schools. Sample sizes are unweighted. b Usual intake distributions were determined for each subgroup using the PC version of the Software for Intake Distribution Estimation (version 1.0, 2003, Iowa State University, Ames). Sample includes all children, including those who did not consume a lunch. c AMDR Acceptable Macronutrient Distribution Range. d NA not available. Standard error could not be estimated for percentages very close to 0 or 100 or for percent within AMDR. e Statistic is potentially unreliable due to a small sample size and/or a coefficient of variation 30%. f DGA Dietary Guidelines for Americans 2005 recommendation (16). g EAR Estimated Average Requirement. h The EAR for vitamin C is 35 mg greater for smokers than nonsmokers. These tabulations used EARs for nonsmokers. i Niacin intakes include preformed niacin only. EARs for niacin are expressed as niacin equivalents, including contributions from tryptophan. Therefore, prevalence of inadequate niacin intakes may be overestimated. j Comparison to EAR was done using the probability approach. Standard errors were not estimated, and the significance of differences between participants and was not tested.

8 children. Among high school aged children, nutrient inadequacy was more prevalent among females than males (Table 3). Among male high school students, the prevalence of inadequacy exceeded 15% for vitamin A, vitamin C, vitamin E, and magnesium. Among female high school students, the prevalence of inadequacy exceeded 15% for all these nutrients plus vitamin B-6, folate, thiamin, iron, phosphorus, and zinc. Calcium, Potassium, and Sodium. EARs have not been defined for calcium, potassium, or sodium. In Table 2, intakes of these minerals are reported as the mean percentage of the relevant AI. Mean intakes of calcium were equivalent to 96% of the AI, overall. Among elementary school children, the mean calcium intake was equivalent to 112% of the AI, which suggests that few children in this subgroup had inadequate intakes of calcium. Mean calcium intakes of middle and high school aged children were less than the AI, and mean potassium intakes were less than the AI for all three groups of school-aged children. The usual sodium intakes of the vast majority of children exceeded the UL. Fiber and Cholesterol. Mean fiber intakes of all groups of children were less than the AI and well below the 14 g/1,000-kcal benchmark on which the fiber AIs are based. The prevalence of excessive cholesterol intakes, relative to the 2005 Dietary Guidelines recommendation of 300 mg per day, ranged from 5% among middle school children to 21% among high school aged children. Differences in the Usual Intakes of NSLP and Nonparticipants Table 4 presents mean daily energy intakes, mean EERs, and estimates of the prevalence of nutrient inadequacy and excess for NSLP participants and matched samples of. Overall, mean EERs were similar for NSLP participants and matched, but NSLP participants had significantly greater energy intakes (about an additional 130 kcal over 24 hours). This pattern was noted for all three age groups, and differences in mean energy intakes were statistically significant for elementary and high school aged children. There were no substantive differences in intakes of any macronutrients; roughly 80% of NSLP participants and matched had saturated fat intakes that exceeded the 2005 Dietary Guidelines, and 90% of children in both groups had intakes of carbohydrate and protein within the AMDR. NSLP participants overall were significantly less likely than matched to have inadequate intakes of magnesium and phosphorus. Both these differences were driven by participant nonparticipant differences at both the middle and high school levels. In addition, for both middle and high school aged children, NSLP participants were less likely to have inadequate intakes of vitamin A. Among high school aged children, the prevalence of inadequate intakes of vitamin C, B-6, folate, and thiamin was significantly lower for NSLP participants. Overall, mean intakes of calcium (expressed as a percentage of the AI) were significantly higher for NSLP participants than for matched. These patterns were observed for all three age groups, but differences were statistically significant only for middle and high school aged children. Among high school aged children, NSLP participants were significantly more likely to have usual sodium intakes that exceeded the UL. Among middle and high school aged children, NSLP participants also had significantly higher mean intakes of potassium than matched. NSLP participants had significantly higher mean intakes of fiber; this difference was observed for children at all three grade levels. Differences in the Usual Intakes of SBP and Nonparticipants Table 5 presents mean energy intakes, mean EERs, and estimates of the prevalence of nutrient inadequacy and excess for SBP participants and matched samples of. Overall, mean energy intakes and EERs were comparable for SBP participants and. Point estimates for the proportion of participants with total fat intakes in excess of the AMDR were higher than for, but, again, these differences were not statistically significant. The prevalence of usual saturated fat intakes in excess of 2005 Dietary Guidelines recommendations was comparable for both groups. The same was true for the prevalence of inadequate usual intakes of protein and carbohydrate. SBP participants were significantly less likely than matched to have inadequate intakes of vitamin A and phosphorus. These patterns were noted for children in all three age groups, although the differences were generally not statistically significant in the agegroup specific analyses. Prevalence of inadequacy was also lower among participants for magnesium and zinc, but the differences were generally not statistically significant. Overall and among elementary school children, SBP participants had significantly higher mean potassium intakes than matched. Point estimates of mean calcium intakes as a percent of the AI were also higher for SBP participants than for matched, although the differences were not statistically significant. SBP participants were also significantly more likely to have usual sodium intakes that exceeded the UL. This pattern was noted for all three age groups but was significant only for middle school children. DISCUSSION The SNDA-III data provide the most accurate picture of children s school-day diets and of the relationship between school meal program participation and the nutritional quality of children s diets. Overall, the majority of school-aged children in the US had nutritionally adequate diets but excessive intakes of saturated fat and sodium. The relationship between EERs and reported energy intakes varied by grade level. On average, reported energy intakes of elementary school children exceeded EERs, and reported energy intakes of middle and high school aged children were less than their respective EERs. These results may reflect overreported food intakes for young children and underreported food intakes for older children and adolescents, particularly adolescent females (8). February 2009 Supplement to the Journal of the AMERICAN DIETETIC ASSOCIATION S51

9 Table 4. Percentage of National School Lunch Program (NSLP) participants and matched with acceptable, inadequate, or excessive usual daily intakes abc All Children Elementary School Children Middle School Children High School Children Dietary component (n 1,385) (n 506) (n 531) (n 142) (n 496) (n 176) (n 358) (n 188) 4 mean standard error 3 Energy Intake (kcal) 2, , ** 2, , ** 2, , , , ** Estimated Energy Requirement (kcal) 2, , , , , , , , Macronutrients Total fat % within AMDR d 76.8 NA e 94.2 NA 77.4 NA 87.0 NA 78.8 NA 95.1 NA 68.4 NA 63.5 NA % AMDR f f f f f f 9.05 % AMDR f f 8.53 Saturated fat % DGA g f f f Carbohydrate % EAR h NA 3 NA NA 3.1 f 2.26 % within AMDR 96.6 NA 97 NA 93.5 NA 97 NA 97 NA 97 NA 95.7 NA 84.8 NA % AMDR NA f 7.09 % AMDR NA 4.2 f NA 4.3 f f 8.95 Protein % EAR 3 NA 3 NA 3 NA 3 NA 3.2 f NA 3 NA 3 NA % within AMDR 97 NA 94.1 NA 97 NA 97 NA 97 NA 93.4 NA 96.7 NA 89.4 NA % AMDR 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA % AMDR f f f f 6.11 Vitamins and minerals with EARs (% <EAR) Vitamin A f * * Vitamin C i f f f * Vitamin E f f Vitamin B f NA 6.1 f f ** Vitamin B f f f 8.55 Folate f f f f ** Niacin j NA f 5.95 Riboflavin NA f f 6.94 Thiamin f f f f ** Iron k 3 NA 3 NA 3 NA 3 NA 3 NA 3.2 f NA 8.8 f NA 9.5 f NA Magnesium ** f ** Phosphorus ** f f ** Zinc 4.0 f f f f f f f 8.86 Calcium, potassium, and sodium Calcium (mean % AI) l f * f f ** * Potassium (mean % AI) * ** Sodium (% Tolerable Upper Intake Level) f f * Other dietary components Fiber (mean % AI) ** * * * Cholesterol (% DGA 9.1 f f f f f f f f 9.54 a Data are from the third School Nutrition Dietary Assessment Study, 24-hour dietary recalls, school year Tabulations are based on first and second 24-hour recalls and weighted to be nationally representative of children in public NSLP schools. Sample sizes are unweighted. b Usual intake distributions were determined for each subgroup using the PC version of the Software for Intake Distribution Estimation (version 1.0, 2003, University of Iowa, Ames). Sample includes all children, including those who did not consume a lunch. c sample constructed using propensity-score matching to adjust for differences in personal, family, and school characteristics between NSLP participants and, including age, sex, race and ethnicity, height, household income relative to poverty, region, and several other characteristics, as described in text. Estimates weighted to account for sample design and the fact that children in the comparison group may be matched to multiple participants. d AMDR Acceptable Macronutrient Distribution Range. e NA not available. Standard error could not be estimated for percentages very close to 0 or 100 or for percent within AMDR. f Indicates a statistic that is potentially unreliable due to a small sample size and/or a coefficient of variation 30%. g DGA Dietary Guidelines for Americans 2005 recommendation (16). h EAR Estimated Average Requirement. i The EAR for vitamin C is 35 mg greater for smokers than nonsmokers. These tabulations used EARs for nonsmokers. j Niacin intakes include preformed niacin only. EARs for niacin are expressed as niacin equivalents, including contributions from tryptophan. Therefore, prevalence of inadequate niacin intakes may be overestimated. k Comparison to EAR was done using the probability approach. Standard errors were not estimated, and the significance of differences between participants and was not tested. l AI Adequate Intake. *Difference between participants and matched is significantly different from zero at the 0.05 level. **Difference between participants and matched is significantly different from zero at the 0.01 level. S52 February 2009 Suppl 1 Volume 109 Number 2

10 Table 5. Percentage of School Breakfast Program (SBP) participants and matched with acceptable, inadequate, or excessive usual daily intakes abc All Children Elementary School Children Middle School Children High School Children Dietary component (n 381) (n 302) (n 160) (n 118) (n 127) (n 99) (n 94) (n 85) 4 mean standard error 3 Energy Intake (kcal) 2, , , , , , , , Estimated Energy Requirement (kcal) 1, , , , , , , , Macronutrients Total fat % within AMDR d 77.3 NA e 83.5 NA 70.6 NA 79.4 NA 63.5 NA 69.1 NA 74.0 NA 48.2 NA % AMDR 20.3 f f f f f % AMDR f f NA 5.0 f f 8.56 Saturated fat % DGA g f Carbohydrate % EAR h 3 NA NA NA NA % within AMDR 96.9 NA 97 NA 89.2 NA 97 NA 95.2 NA 86.3 NA 94.0 NA 79 NA % AMDR f f 6.42 % AMDR f f f f f Protein % EAR 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA % within AMDR 97 NA 97 NA 97 NA 97 NA 97 NA 97 NA 93.7 NA 97 NA % AMDR 3 NA 3 NA 3 NA 3 NA 3 NA 3 NA NA % AMDR f Vitamins and minerals with EARs (% <EAR) Vitamin A 13.4 f * 5.9 f f f f Vitamin C i 5.4 f f f NA 10.2 f Vitamin E f f f 8.11 Vitamin B f Vitamin B f f 7.01 Folate f f f 9.45 Niacin j f Riboflavin NA f f 4.72 Thiamin NA f f f 7.11 Iron k 3 NA 3 NA 3 NA 3 NA 3 NA 3.6 f NA 7.7 f NA 8.5 f NA Magnesium 20.6 f f f f * 75.3 f f 8.55 Phosphorus 7.4 f * 3.9 f * 19.6 f Zinc f f f f f 9.56 Calcium, potassium, and sodium Calcium (mean % AI l ) f f f f f 4.38 Potassium (mean % AI) ** * Sodium (% Tolerable Upper Intake Level) 97 f * 97 f f ** 97 f f Other dietary components Fiber (mean % AI) Cholesterol (% DGA) 12.9 f f f f f a Data are from the third School Nutrition Dietary Assessment Study, 24-hour dietary recalls, school year Tabulations are based on first and second 24-hour recalls and weighted to be nationally representative of children in public NSLP schools. Sample sizes are unweighted. b Usual intake distributions were determined for each subgroup using the PC version of the Software for Intake Distribution Estimation (version 1.0, 2003, University of Iowa, Ames). Sample includes all children, including those who did not consume a breakfast. c sample constructed using propensity-score matching to adjust for differences in personal, family, and school characteristics between SBP participants and, including age, sex, race and ethnicity, height, household income relative to poverty, region, and several other characteristics, as described in text. Estimates weighted to account for sample design and the fact that children in the comparison group may be matched to multiple participants. d AMDR Acceptable Macronutrient Distribution Range. e NA not available. Standard error could not be estimated for percentages very close to 0 or 100 or for percent within AMDR. f Statistic is potentially unreliable due to a small sample size and/or a coefficient of variation 30%. g DGA Dietary Guidelines for Americans 2005 recommendation (16). h EAR Estimated Average Requirement. i The EAR for vitamin C is 35 mg greater for smokers than nonsmokers. These tabulations used EARs for nonsmokers. j Niacin intakes include preformed niacin only. EARs for niacin are expressed as niacin equivalents, including contributions from tryptophan. Therefore, prevalence of inadequate niacin intakes may be overestimated. k Comparison to EAR was done using the probability approach. Standard errors were not estimated, and the significance of differences between participants and was not tested. l AI Adequate Intake. *Difference between participants and matched is significantly different from zero at the 0.05 level. **Difference between participants and matched is significantly different from zero at the 0.01 level. February 2009 Supplement to the Journal of the AMERICAN DIETETIC ASSOCIATION S53