School lunch: A comparison of the fat and cholesterol content with dietary guidelines

ORIGINAL ARTICLES

School lunch: A comparison of the fat

and cholesterol content with dietary guidelines Robert C. Whitaker, MD, MPH, J e f f r e y A. Wright, MD, A n i t a J. Finch, RD, MS, Richard A. Deyo, MD, MPH, a n d Bruce M. Psaty, MD, PhD From the Departments of Pediatrics and Medicine and the Robert Wood Johnson Clinical Scholars Program, Universityof Washington School of Medicine, Seattle, the Bellevue Nutrition Services, Bellevue School District No. 405, Bellevue, Washington, the Departments of Health Services and Epidemiology, Universityof Washington School of Public Health and Community Medicine, Seattle, and the Seattle Veterans Affairs Medical Center, Seattle, Washington

Objective: To compare the fat and cholesterol content of the foods offered and selected in an e l e m e n t a r y school lunch program with current dietary guidelines. Design: For 105 school days we recorded the food items selected by e l e m e n t a r y school students in an entire school district (262,851 meals) who were given a c h o i c e between two entrees. The nutrient content of foods was assessed with a computerized nutrient data base supplemented by the food manufacturers' data. Setting:Sixteen e l e m e n t a r y schools in the Bellevue (Washington) School District. Participants: The number of students eating school lunch a v e r a g e d 2500 per day, of whom 25% were from households with incomes less than 185% of poverty. Intervention: None. Main outcome measures; We determined the nutritional content of the a v e r a g e meal selected; the proportion of days when one of the two offered entrees met fat and cholesterol guidelines; and the proportion of children selecting the entrees that met the guidelines. Results: The a v e r a g e lunch selected had 35.9% of calories from total fat and 12.6% from saturated fat, e x c e e d i n g the guidelines of 30% and 10%, respectively. Lunch contained an a v e r a g e of 57 mg cholesterol (106 mg/1000 kcal) and met guidelines. One of the two d a i l y entree choices met guidelines for both total fat and saturated fat on 20% of days, and met both fat and cholesterol guidelines on 14% of days. When a v a i l a b l e , entrees meeting the fat guidelines were chosen by 37% of students, and entrees meeting both fat and cholesterol guidelines were chosen by 34% of students. Conclusions: In this school district the a v e r a g e lunch selected did not meet the current guidelines for dietary fat; when given the choice, more than one third of students selected the entrees that met these guidelines. (J PEDIATR 1993;123: 857-62)

Supported by a grant from the Robert Wood Johnson Foundation, Princeton, N.J. Dr. Whitaker was a fellow in the Robert Wood Johnson Clinical Scholars Program. The opinions and conclusions in the text are those of the authors and do not necessarily represent views of the Robert Wood Johnson Foundation.

Submitted for publication April 28, 1993; accepted July 13, 1993. Reprint requests: Robert C. Whitaker, MD, MPH, Children's Hospital and Medical Center, CH-98, Box C5371,4800 Sand Point Way, NE, Seattle, WA 98105-0371. 9/20/50071

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Dietary guidelines suggest that the U.S. population should reduce its consumption of fat and cholesterol to reduce the risk of cardiovascular disease, obesity, and some forms of cancer. 16 Because dietary habits are thought to develop early in life, and because diet contributes to the development of chronic diseases through years of exposure, these recommendations extend to all children older than 2 years of age. The American Academy of Pediatrics, the American Heart Association, the National Research Council, the National Cholesterol Education Program, the U.S. Department of Agriculture (USDA), and the U.S. Department of Health and Human Services all suggest reducing dietary fat and saturated fat to less than 30% and less than 10%, respectively, of calories. Most of these groups also recommend limiting dietary cholesterol to 300 mg/dayJ -4 Although these guidelines exist for children, there is little information about whether school districts in the USDAadministered National School Lunch Program meet these objectives and, if not, whether it is feasible to achieve them. The NSLP provides lunch to 24.5 million U.S. children, about 60% of all public-school children.7 Therefore the program has a substantial impact on the overall nutrition of U.S. children and may also play an important role in the formation and reinforcement of dietary habits. Furthermore, school lunch programs provide an environment to assess whether foods low in fat and cholesterol are acceptable to children. The purpose of this study was to estimate the fat and cholesterol content of the foods offered to, and selected by, elementary students in a school lunch program, and to assess the feasibility of meeting the dietary guidelines. METHODS Research setting. The study was conducted in the Bellevue (Washington) School District and was approved by both the school district and the University of Washington Human Subjects Review Committee. This school district had 6700 students in its 16 elementary schools. Each day an average of 2500 students (38% of those enrolled) ate the school lunch, and the remainder brought lunch from home. In this study we examined only those who ate the school lunch. Of these school lunch participants, 25% received free or reduced-price lunches. To be eligible for free or reducedprice lunches, the child's family income had to be less than $23,495 per year for a family of four (185% of the federal poverty level in 1990). Since 1981 the USDA has allowed elementary schools to use an "offer" rather than a "serve" system to reduce food waste, s In the "offer" system, which was used by this school district, students were required to select only three of the five components in the USDA-established meal pattern: (1) meat or meat alternative, (2) bread, (3) fruit, (4) vegeta-

The Journal of Pediatrics December 1993

ble, and (5) milk. In this district the entree usually included both the meat and the bread components. Students were allowed a choice between two daily entrees, which were the same throughout the district. All food was prepared in a central kitchen; standard serving sizes were distributed to each school. On a daily basis, each student eating school lunch ordered one of the two entrees during the first class. None of the entrees was advertised to students, parents, or teachers as being "healthy," "low fat," or "low cholesterol." The entree orders were recorded at the central kitchen, which provided a daily count of the total number of students in the district selecting each type of entree. This kitchen record, however, did not contain the entree choices of individual students or the number of nonentree items selected. At lunch, students entered a self-serve line and took their ordered entree. They then chose among cut raw vegetables, green salad with dressing, and assorted canned or fresh fruits. They were allowed to choose up to two servings from this fruit and vegetable group. All milk was 1% fat, and chocolate milk was offered 1 day per week. Dessert and nonentree bread items were also occasionally offered. NSLP

National School Lunch Program

Data collection. The objective was to determine (1) the nutritional content of the average meal selected by students each day, (2) the proportion of days when one of the two entrees met dietary guidelines, and (3) the proportion of students choosing the entree that met dietary guidelines. To accomplish these objectives, we combined two types of data: (1) food-selection data (i.e., the number of servings of each food item--entrees and nonentree items--selected each day in the district) and (2) nutritional analysis data (i.e., the nutrient content per serving of each food item). The method of collecting each type of data is detailed below. We analyzed 105 of the 107 school days (98%) in the first 6 months of the 1990-1991 school year. We excluded the 2 clays when students were not given preportioned servings. Analysis of these 105 school days reflects data aggregated from a total of 262,851 meals. Food selection data. The kitchen order sheets gave the number of each entree type ordered and were available for all 105 days. The kitchen delivered only the number of entrees ordered, so the kitchen order count equaled the number of entrees selected on the lunch line and the number of students eating school lunch. Because the number of nonentree items selected was not routinely recorded, we estimated their contribution to the nutritional content of the average meal selected each day by counting the number of each nonentree item selected during 30 consecutive lunch days. For each nonentree item, we determined the average proportion of students selecting it

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Table I. Nutritional content of the average school lunch

Table II. Percentage of days when one entree met

selected on 105 school days and the current dietary recommendations for children

dietary guidelines and the mean proportion of students selecting that entree

Nutrient Fat (%kcal) Saturated fat (%kcal) Polyunsaturated fat (%kcal) Cholesterol Unit: mg Unit: mg/1000 kcal Protein (%kcal) Carbohydrate (%kcal)

Average school Dietary lunch* guideline'i" 35.9 + 5.0 12.6 _+ 2.4 7.5 _+ 2.1

--<3015 _<10~-5

58 + 14 106 _+ 28 19.6 _+ 2.2 44.5 _+ 4.6

-<100~ I-4

102-4

-<100~ 10-152-4 50-602-4

*Values are expressed as mean _+SD. tSuperscript numerals are referencecitations. :[:Onethird of daily recommendedamount.

Guideline Calories from fat: _<30% ([) Calories from saturated fat: _<10% (II) Cholesterol per 1000 calories: -<100 mg (III) I and II I, II, and III

Guidelines met (% days)

Students selecting entree* (%)

23

39 _+ 21

53

32 _+ 20

52

61 _+ 27

20 14

37 _ 22 34 _+ 24

*Percentages are expressedas mean _+SD. when it was offered. For the 105 study days we multiplied this average proportion by the number eating. This calculation estimated how many servings of each nonentree item were selected. Combining these nonentree estimates with the daily entree counts yielded the number of servings of every food item selected by the students. Nutritional analysis data. Thirty-four entrees and thirty nonentree items were offered. To determine the nutritional content of these 64 items, we used the Food Processor II software program (ESHA Research, Salem, Ore.) supplemented by nutrient data obtained directly from food manufacturers. The computer database is derived from current U S D A Handbook Number Eight values and from approximately 450 other references, including both scientific publications and data from food manufacturers. 9 The kitchens prepared some of their entrees, desserts, and baked goods from recipes, and these were analyzed with the software program. We contacted food manufacturers supplying the school district to obtain nutrient data for processed foods such as frozen pizza and hot dogs. Data analysis. Combining information from each of the two data sources (food selection and nutritional analysis), we calculated the nutritional content of the average meal selected in the school district for each of the 105 study days and used these daily averages as the units of analysis. We applied conventional energy conversion factors to determine the percentage of calories from macronutrients: four calories per gram of protein or carbohydrate and nine calories per gram of fat. RESULTS

Student characteristics. The children in this study ranged in age from 5 to 10 years. Seventy-eight percent were white, 15% were Asian, and 4% were black. In the United States as a whole, a similar proportion of children of this age are

nonwhite, but more of the nonwhite children are black and/or of Hispanic origin. 1~ One measure of the socioeconomic status of the school district is the proportion of students receiving free or reduced-price meals. Nationwide, 33.4% of all schoolchildren receive these subsidized meals (Pat McKinney, U S D A Food and Nutrition Service: personal communication, June 1993) compared with 9.4% of elementary school students in this school district. Nutritional content of school lunches. The average lunch selected had a greater proportion of calories from total fat and saturated fat than is advised for children older than 2 years of age 1-5 (Table I). A greater percentage of the nonfat calories were from protein, and fewer from carbohydrate, than is recommended. Cholesterol content was less than one third of the daily recommendation of 300 mg but slightly exceeded the calorie-adjusted recommendation of 100 rag/1000 kcal. The energy in the average lunch selected by students was 553 kcal; for 5- to 10-year-old students, one third of the recommended dietary allowance ranges from 514 to 691 kcal. 11 The average lunch contained only 0.94 serving of fruit, 0.18 serving of salad (including dressing), and 0.09 serving of the raw vegetables, even though a total of two servings were allowed from these foods. Milk was chosen by 92% of students. The entree and milk, therefore, constituted the majority of calories and fat in the average lunch. The entree alone accounted for an average of 63% of the calories and 76% of the total fat. The entree plus milk accounted for 83% and 87% of the calories and total fat, respectively. Table II shows the proportion of days that at least one of the two lunch entrees met the particular guidelines for total fat, saturated fat, and cholesterol. On more than half the days, one entree had 10% or fewer calories from saturated

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The Journal of Pediatrics December 1993

T a b l e III. Nutritional content of the average meal selected by students on days with and days without an available low-fat entree

Nutrient

Energy (kcal) Total fat (%kcal) Saturated fat (%kcal) Cholesterol (rag/1000 kcal)

On days On d a y s with low-fat without low-fat e n t r e e c h o i c e entree c h o i c e (n = 24) (n = 81)

p*

559.0

551.0

0.65

32.4

36.9

0.001

11.0

13.1

<0.001

108.0

106.0

0.64

Low-fat entree had --<30%of calories from total fat. *Values obtained by t test.

fat. However, on 23% of days an entree was available that had 30% or fewer calories from fat, and on 20% of days an entree met the guidelines for both total and saturated fat. A low cholesterol entree was also available on more than half the days, but on only 14% of days did an entree meet total fat, saturated fat, and cholesterol guidelines. No entree offered had fewer than 10% of calories from protein or more than 55% of calories from carbohydrate. On average, one third or more of the students selected the entree meeting the particular guidelines (Table II). T[ae low-cholesterol entree was chosen by more than 60% of students when it was available. This high proportion is explained by the fact that pizza, which was selected by 89% of students when it was offered each Wednesday, met the cholesterol guidelines but had 44% of calories from fat. The fat content of the average meal selected was determined in part by the fat content of the two different entrees offered and in part by the proportion of children choosing each type of entree. On days when a Iow-fat entree was available, the total fat and saturated fat content of the average meal was significantly lower (Table iII). Neither the energy nor the cholesterol content of the average meal was significantly different on the days with and without a lowfat entree. DISCUSSION The average school lunch selected by elementary school students in this Washington school district did not meet the current dietary recommendations for children. Although it had a higher percentage of calories from fat and saturated fat than was recommended, it met the guidelines for dietary cholesterol and was no higher in fat than the overall diets of U.S. children this age. 12' 13 More than one third of children chose an entree meeting all three guidelines (total fat,

saturated fat, and cholesterol) when such an entree was available. Some data are available on the nutritional content of lunches in other U.S. elementary schools, but these data may not be comparable to our own because they are based on dietary recalls. 14-19 In 1980 the U S D A conducted the National Evaluation of School Nutrition Programs. v, 14, I5 Single dietary recalls were completed on the school lunch items consumed by 1127 children, aged 5 to 10 years, from 848 sampled school districts. The Bellevue lunch had a similar number of calories (553 kcal vs 563 keal) but a lower percentage of calories from fat (35.9% vs 38.8%). Two smaller, but more recent, studies also reported a greater percentage of calories from fat and saturated fat than we found in this district. 18, 19 Snyder et al. 2~ found that the percentage of calories from fat dropped from 39.8% to 28.3% after an intervention to reduce dietary fat. Our findings may not apply to some other school lunch programs because the foods offered in the Bellevue School District may have been lower in fat. At the time of the study, the school district was the only one in Washington with a full-time nutrition educator working on menu planning. Nevertheless, the menus in this school lunch program still contained many high-fat entrees that are served in other school districts throughout the country. Several of the entrees, including the two most popular (pepperoni pizza, 44% of calories from fat; and chicken nuggets, 60% of calories from fat), were purchased from large manufacturers supplying hundreds of school districts. In addition, this district, like most others, used U S D A commodities, many of which are high in fat. The National School Lunch Act of 1946 (Public Law 79-396) was enacted to "safeguard the health and well-being of the Nation's children and to encourage the domestic consumption of nutritious agricultural commodities." The USDA, as administrator of the NSLP, is in a position to extend the dietary guidelines to the school lunch and to see that the commodities used in the program are consistent with these guidelines. Furthermore, the implementation of these guidelines in federal nutrition programs is explicitly called for by the U.S. Department of Health and Human Services. 21 According to the National Cholesterol Education Program's Expert Panel on Blood Cholesterol Levels in Children and Adolescents, a population approach "serves as the principal means for preventing coronary heart disease. ''4 Implementing the dietary guidelines in school lunch programs is one population-based mechanism for reducing cardiovascular disease risk among children. Our method of assessing the nutritional content of the school lunch had several strengths. First, we based our results on the foods selected rather than on the foods offered. There was a daily choice between entrees that on many days

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had markedly different fat content (17% to 60% of calories from fat); there was also a choice among fruits, vegetables, and milk. We accounted for all potential choices. Second, we unobtrusively monitored food selection by employing an entree-count system already in place. Third, our nutritional analysis was derived from the actual recipes and serving sizes usedl Finally, we analyzed 98~ of the lunch days during the 6-month study period. The dietary guidelines are meant to be goals for an average ongoing diet because there is clay-to-day variation in food intake. By analyzing all days and aggregating across large numbers of students for several months, we may have provided a better overall view of the nutritional content of school lunches than other techtuques that involve sampling a small number of individuals or days. Our method emphasizes the diet of a poptilation of schoolchildren rather than the diets of individuals, and it provides a tool to assess dietary behavior outcomes for school-based health-promotion interventions. Our method also had limitations. W e did not perform dietary recalls and could not determine the actual consumption of individual students. The data were derived from food disappearance in a defined population eating school lunch and provided only an estimate of the foods actually eaten. Although consumption data for school lunches can be obtained through dietary recall, 22 this method also has limitations. 23 It is expensive, impractical to perform on repeated occasions with large numbers of children, and not free from recall bias. 24 This study suggests a potential intervention for meeting the dietary guidelines in school lunch programs. Nearly 40% of children selected the low-fat entree (__30% of calories from total fat) when one was available, but these entrees were available on 0nly 23% of days during the study period, ff just one of the two daily entrees were low in fat, and if this option were available every day, the fat content of the average meal might drop significantly. W e demonstrated in an intervention study that such dietary fat reduction can be achievedY One barrier that schools face in meeting the dietary guidelines is determining the fat content Of the foods served. Recipes can be analyzed, as we have done, with a computerized nutrient database. Many districts, however, purchase highly processed foods from vendors. Currently, the food manufacturer must only certify that products used in school lunch programs contain an appropriate amount (by weight) of a meal pattern component (e.g., m e a t / m e a t alternative or bread). A U S D A requirement that food manufacturers provide data on fat content might be helpful to schools in their menu planning. W e conclude that school lunch in this district had more fat and more saturated fat than are currently recommended. Nevertheless, more than one third of children selected low-

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fat entrees when they were made available. Increasing the availability of low-fat foods in school lunch programs, without eliminating choice, may be a feasible populationbased approach to meet current dietary guidelines for children. We are grateful to Jay Pearson, Helen Westtund, and Cathy Dumas, of the Bellevue School District, for their support; to Drs. Thomas Inui for his guidance; to Dr. Thomas Koepsell for his statistical advice; and to Lydia Lewis for technical support. REFERENCES

1. American Academy of Pediatrics Committee on Nutrition. Statement on cholesterol. Pediatrics 1992;90:469-73. 2. Weidman W, Kwiterovich P Jr, Jesse M J, Nugent E. Diet in the healthy child. Report of the Task Force Committee Of the Nutrition Committee and the Cardiovascular Disease in the Young Council of the American Heart Association. Circulation 1983;67:141 la-4a. 3. National Research Council (Committee on Diet and Health, Food and Nutrition Board, Commission on Life Sciences). Diet and health: implications for reducing chronic disease risk. Washington, D.C.: National Academy Press, 1989. 4. National CholesterOl Education Program. Report of the Expert Panel on Blood Cholesterol Levels in Children and Adolescents. Pediatrics 1992;89:525-84. 5. U.S. Department of Agriculture, U.S. Department of Health and Human Services. Nutrition and your health: dietary guidelines for Americans. 3rd ed. (HG bulletin No. 232.) Washington D.C.: U.S. Government Printing Office, 1990. 6. U.S. Department of Health and Human Services, Public Health Service. The Surgeon General's report on nutrition and health. (Publication No. (PHS) 88-50210.) Washington, D.C.: U.S. Government Printing Office, 1988. 7. Radzikowski J, Gale S. Requirement for the National Evaluation of School Nutrition Programs. Am J Clin Nutr 1984; 40(suppl):365-7. 8. U.S. Congress. Omnibus Reconciliation Act of 1981, Public Law 97-35. Washington, D:C.: U.S. Government Printing Ofrice, 1981. 9. Hands ES. Food finder: food sources of vitamins and minerals. Salem, Oregon: ESHA Research, 1990. 10. Bureau of the Census. 1990 Census of Population and Housing: summary population and housing characteristics, Washington. (Publication No. CPH- 1-49, 1991 .) Washington, D.C.: U.S. Government Printing Office, 1991. 11. National Research Council Commission on Life Sciences and Food and Nutrition Board. Recommended dietary allowances. 10th ed. Washington, D.C.: National Academy of Sciences Press, 1989. 12. Carroll MD, Abraham S, Dresser CM. Dietary intake source data: United States 1976-1980. (Publication No. [PHS] 831681 [Vital and Health Statistics, series 2, No. 231].) Hyattesville, Maryland: National Center for Health Statistics, 1983. 13. U.S. Department of Agriculture, Human Nutrition Information Service. Food and nutrient intakes, by individuals in the United States, one day, 1987-1988. (Nationwide Food Consumption Survey, 1988, publication No. 87-I- 1.) Washington, D.C., U.S. Government Printing Office, 1993. 14. Hanes S, Vermeersch J, Gale S. The National Evaluation of

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