Effectiveness of a school-based intervention to increase health knowledge of cardiovascular disease risk factors among rural Mississippi middle school children.

Background: Few school-based interventions have been evaluated to assess health awareness among children in rural southern areas. The purpose of this controlled investigation was to increase health awareness among middle school-aged children residing in a racially diverse rural community in Mississippi.

Methods: This investigation assessed health knowledge before and after a 16-week school-based intervention in 205 fifth-grade students. Height, weight, BMI, body composition, waist circumference, dietary intake, blood lipids and lipoprotein concentrations, blood glucose concentrations, and resting blood pressure were measured to enhance student awareness of cardiovascular disease risk factors. Values in the intervention school were compared with those obtained simultaneously in a control school within the same community.

Results: The school-based intervention was effective in increasing health knowledge in the intervention as compared with the control school. Secondarily, it was effective in improving certain dietary behaviors. Utilizing health care professionals in the classroom to teach students appropriate lifestyles and actually measuring cardiovascular risk factors to increase awareness among students was effective in increasing overall health knowledge.

Conclusions: Health knowledge of rural adolescents can be increased through partnerships with schools and multidisciplinary teams of health care professionals. Ongoing efforts to reduce childhood obesity and cardiovascular disease risk factors are urgently needed, and information obtained during this investigation may be used in planning school-based interventions in other diverse, rural communities.

Key Words: children, dietary intake, physical activity, overweight, health disparities.

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Childhood obesity has become a significant health care concern in the United States. It is estimated that among US children aged 6 to 19 years, one-third are overweight or at risk for overweight, which is a more than twofold increase over the past two decades. (1,2) The potential impact of this epidemic is enormous, given that obesity in childhood has been identified as a risk factor for the development of chronic diseases later in life. (3-5) Epidemiologic evidence suggests that precursors of cardiovascular diseases (CVD) begin in childhood, and that increased blood pressure levels in children will likely lead to hypertension in young adulthood. (6) Furthermore, the prevalence of type 2 diabetes mellitus in the pediatric population has closely paralleled the prevalence of childhood obesity, indicating that obesity is also the principal contributor to the epidemic of diabetes in children and adolescents. (7) Obesity has also been linked to other chronic diseases including arthritis, sleep disorders, gallbladder disease, heart failure, and stroke. (8)

Contributors to the development of obesity include a sedentary lifestyle, increased caloric intake, and poor nutritional habits. High consumption of saturated fat, sodium and caffeinated soft drinks, and a low consumption of fruits, vegetables, and fiber-rich grains are associated with an increased risk for CVD. (9,10) Dietary guidelines for CVD risk reduction recommend that all healthy individuals over the age of two should consume five or more servings of fruits and vegetables per day, an adequate intake of fiber-rich foods, a moderate intake of foods with high sugar content, and a limited intake of foods containing high amounts of saturated fat, cholesterol, and sodium. (9)

CVD is more prevalent in the southeastern US, particularly in the state of Mississippi, which leads the nation in CVD mortality. (1) The contributing factors to this phenomenon are unknown, but one potential cause may be related to population distribution. Over half of Mississippi is classified as rural, which has been reported as a possible factor in health disparities within the state. (11) Other possible causes include lower socioeconomic status, poor dietary habits, physical inactivity, and a high prevalence of obesity. (12)

Very little research regarding health disparities among children in rural areas has been conducted. The Bogalusa Heart Study and the Child and Adolescent Trial for Cardiovascular Health (CATCH) study reported comparable rates of overweight and obesity (approximately 30%); however, these investigations only reported data collected through 1994 and prevalence rates have likely increased. (13,14) Most obesity data have been obtained through national surveys, some of which include self-reported weight and height. It has been demonstrated that actual obesity prevalence rates may be more than 50% higher than estimates from the self-reported surveys. (15)

The purpose of this investigation was to evaluate the effectiveness of a school-based pilot intervention program aimed at increasing knowledge of CVD risk factors among fifth grade students in a rural Mississippi community.

Methods

Subjects

All children in the fifth grade at two middle schools in Scott County, Mississippi were recruited for participation in this investigation. The two schools were selected based upon their close geographic proximity, similar demographic characteristics (eg, socioeconomic levels, racial diversity), and the teachers'/administrators' willingness to participate. Written parental consent was obtained for all participants before enrollment. A total of 205 children were enrolled in the investigation. The Institutional Review Board of the University of Mississippi Medical Center approved the protocol and informed consent document for this investigation. The funding received for the study was provided through a grant from the Pfizer Foundation. The investigation was conducted through the science classes and received full approval from the administration at both schools.

Primary Outcome--Health Knowledge

The primary outcome measure was health knowledge assessed using the "Know Your Body" health knowledge questionnaire. This questionnaire contains 34 items developed for students aged 10 to 14 years; these items assess knowledge of diet, physical activity, body weight, and cardiovascular health. (16) The score on this questionnaire was expressed as percentage correct (eg, the number of questions answered correctly out of 34 questions).

Secondary Measurement--Metabolic Parameters

Height was determined in each child without shoes using a scale-mounted stadiometer, and weight was measured in light clothing without shoes using a physician's balance scale (Detecto, Webb City, MO). Body mass index (BMI) was calculated for each child, and BMI percentile was determined using the Centers for Disease Control (CDC) BMI-for-age gender specific growth charts. (17) Children were classified as "at risk for overweight" if their BMI percentile was [greater than or equal to] 85th but < 95th, and "overweight" if the BMI percentile was [greater than or equal to] 95th. (8)

Waist circumference was measured in inches by placing a tape measure around the abdomen at the level of the iliac crest. (18,19) Bioelectrical impedance analysis (BIA) was also performed on each child to estimate body fat percentage using a BF-350A body composition analyzer (Tanita, Arlington Heights, IL).

To assess metabolic risk factors, resting arterial blood pressure (BP), blood glucose concentration, blood lipid and lipoprotein concentrations (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides) were assessed at baseline and post intervention. Blood pressure was measured in the seated position after a 5-minute rest period. Arm circumferences were measured to determine appropriate blood pressure (BP) cuff size before measurement; manual sphygmomanometers with pediatric cuffs were used for arm circumferences < 22 cm, and other readings were taken using digital sphygmomanometers (Omron, Vernon Hills, IL). Two BP measurements were taken, with a minimum of a one-minute interval between readings. The mean systolic and diastolic BPs were used to calculate BP percentiles according to National Heart, Lung, and Blood Institute (NHLBI) guidelines. (6) Blood glucose was measured by fingerstick using a standard glucose monitoring system (Ascensia Glucometer Elite, Bayer Corp., Pittsburgh, PA). Blood lipid and lipoproteins were measured by fingerstick using the LDX system (Cholestech, Hayward, CA). The recommended manufacturer suggestions for standard measurements were used for both systems, and the same trained individual performed the measurements at each screening. The time of the child's last meal was also recorded.

A trained interviewer or research dietitian conducted a 24-hour dietary recall on each child using plastic food models (Nasco, Fort Atkinson, WI), measuring cups and spoons at baseline and following the 16-week intervention. School lunch menus were obtained from school foodservice managers to assist the children in correctly recalling breakfast and lunch meals. Recalls were performed with all children on the same two days of the week (Thursday or Friday) so that the day recalled was always a weekday. The rationale for only using weekdays is because this is more representative of a school-aged child's typical week than a weekend day. The recalls were analyzed for macronutrients, micronutrients and caffeine content by the research dietitian using computerized nutritional analysis software designed for research (FIAS Food Intake Analysis System 3.99, University of Texas School of Public Health, Houston, TX). The recalls were then reviewed individually to determine consumption of fruits and vegetables, fluid ounces of soft drinks, and breakfast. These items were chosen based upon their respective association with CVD, obesity and overall nutritional wellbeing of children. (9,20,21)

The Child Dietary Fat Questionnaire (22) was sent home with each child for a parent or caregiver to complete at baseline and after the intervention period. This 17-item questionnaire provides an estimate of the child's intake of fat (% total energy), saturated fat (% total energy), and cholesterol (mg) based on the responses of the parent/caregiver. (22)

[FIGURE OMITTED]

Intervention

The intervention began with the creation of a partnership between the school district and the medical center. First, a multidisciplinary team consisting of physicians, pharmacists, dietitians, and exercise physiologists was formed through the medical center. This team met with the administration of the school district and the middle school where the intervention would take place. The partnership worked together to perform a needs assessment of the middle school, and outlined specific strategies to target all fifth grade students. The plan included classroom sessions, overall school-wide changes, and a family component. The medical team worked with the science teachers to develop interactive educational sessions for one class period per month. There were a total of five science classes participating in the intervention, with each class participating in four educational sessions. The educational sessions covered topics related to a "heart healthy life-style" which included nutrition, physical activity, heart disease, and diabetes. Sessions were instructed by the various team members who included a pediatrician (MD), pharmacist (PharmD), exercise physiologist and registered dietitian (RD). A description of the major educational components of the intervention is provided in Figure 1. In addition, the teachers helped develop materials and incorporated the educational sessions into their monthly lesson plans and testing materials. An additional aspect of the intervention included a poster contest with the theme: "Ways to make our school more heart healthy." Winners were selected and prizes (gift certificates to a sporting goods store) were awarded. As part of the intervention (Fig. 1), the intervention team met with the school administration and food service director regarding the nutritional content of the meals served in the lunchroom and vending machine options. Efforts were made to add fresh fruits and vegetables as healthy options for the students in the school cafeteria, and some healthier items were included as choices in the vending machines. A final component of the intervention was a "Parent's Night" held with the parents of the students who were participating in the intervention during the middle of the project. During this meeting, which was attended by the parents of 35 children, the intervention team provided the baseline biochemical, BP, body weight/composition, and dietary intake data collected on each student to the parents, and provided interpretation of the information. Handouts on heart healthy lifestyles were also provided and questions were answered. Given the rural nature and demographics of this community, many of the parents had not previously had access to a dietitian or exercise physiologist.

The total time involved in the intervention portion of the project was approximately 10 hours per class over the course of one semester. This was in addition to the hours spent in discussions with faculty and administration of the school system. The interaction with students at the control school was limited to the baseline and post testing. Once the intervention was completed, parents of children in the control school were given their metabolic parameter results.

Statistical Analysis

Statistical analyses were performed using computerized statistical analysis software (SPSS 11.0 for Windows, SPSS Inc., Chicago, IL). Repeated measure analysis of variance (ANOVA) was used to determine significant changes in the intervention and control group over time (eg, baseline and post intervention). Pearson correlational analyses were performed to identify relations among variables. Independent samples t tests were used to determine differences between groups. Data are expressed as mean [+ or -] SD. Level of significance was set a priori at P < 0.05.

Results

Subject characteristics

The overall participation rate in the study among the 5th graders in the intervention and control schools was 92% (eg, 112/122) and 72% (eg, 93/130), respectively. The mean age of children in this investigation was 11.9 [+ or -] 0.06 years. Gender distribution of participants by school was not significantly different (intervention school, 62% male and 38% female; control school, 52% male and 48% female). The percentage of 5th grade children in the intervention and control schools that were eligible for free or reduced-cost breakfast and lunches was 70% and 81%, respectively (basis for eligibility is household income below 185% of the federal poverty level). Both schools were racially diverse.

Health Knowledge

Of the 205 children studied, 71% completed the self-administered health knowledge questionnaire both at baseline and post intervention. The average percentage of questions answered correctly on the health knowledge questionnaire increased significantly from 48 [+ or -] 12% to 60 [+ or -] 14% in the intervention school (P < 0.0001); no significant change was found in the control school (43 [+ or -] 14% to 45 [+ or -] 14%, NS). No significant difference by race or gender was detected in health knowledge as a result of the intervention.

Physical characteristics of children in the sample before and after the intervention are provided in Table 1. According to current CDC BMI classifications, >50% of the children in our entire sample were classified at baseline as "overweight" or "at risk for overweight." No significant baseline differences were found in physical characteristics between the schools, with the exception of height. Significant increases in height, weight, and waist circumference were detected over time in our sample (see Table 1). No significant gender differences were detected in physical characteristics over time or as a result of the intervention, with the exception of body fat percentage.

Dietary Intake

Pre- and postintervention dietary intake data was successfully collected on 172 of the 205 children in this sample (84%). Dietary macronutrient and cholesterol, sodium, calcium, fruit, vegetable, soft drink, caffeine intake and breakfast consumption are provided in Table 2. Baseline differences were detected in several dietary intake variables; energy, fat grams (g) and % energy, carbohydrate % energy, saturated fat (SFA) g and % energy, monounsaturated fat (MUFA) g and % energy, cholesterol, caffeine, and breakfast consumption. To adjust for these baseline differences, statistical analyses of pre and post differences in these variables were performed using baseline values as a covariate.

A significant reduction in reported mean energy intake was noted in both groups over time (P < 0.0001) but no difference was noted between schools. The percentage of children at baseline who reported consuming no servings of fruits or vegetables on the day of the recall was 45% and 59%, respectively. As a result of the intervention, a small but significant increase in vegetable consumption was detected in the intervention as compared with the control school (P < 0.05). No significant changes in fruit consumption were detected. In addition, there were no gender differences in fruit or vegetable consumption.

At baseline, approximately 50% of the children in the sample consumed two or more fluid ounces of soft drink on the day of the recall. As shown in Table 2, a significant decrease in soft drink consumption in the intervention as compared with control school was noted (P < 0.05). In the control school, change in BMI and change in body weight were significantly correlated with change in soft drink consumption (r = 0.51, P = 0.003 and r = 0.35, P = 0.05, respectively). These correlations were not significant in the intervention school. No gender differences in soft drink consumption were noted.

Of the 205 children studied, 52% had a parent or caregiver complete the Child Dietary Fat Questionnaire (CDFQ). Mean fat (% total energy), saturated fat (% total energy), and cholesterol intake (mg) estimated using the CDFQ were 35.1 [+ or -] 0.3%, 15 [+ or -] 0.2%, and 270 [+ or -] 14 mg, respectively at baseline and no significant changes with time or by group were detected.

CVD Risk Factors

Metabolic risk factors in our sample pre- and postintervention are provided in Table 3. At baseline, 15% of our sample had "high" or "borderline" resting systolic BP (SBP) readings, and 13% had "high" or "borderline" resting diastolic BP (DBP) readings. (6) No baseline differences in SBP or DBP were detected. Mean values decreased over time in both groups (P < 0.05). No differences by gender or race were noted in resting BP.

With regard to blood lipids and lipoprotein concentrations, 33% of our sample had total cholesterol (TC) concentrations classified as "high" or "borderline" at baseline, and 18% had low-density lipoprotein cholesterol concentrations (LDL-C) that were "high" or "borderline." (23) Baseline differences between groups in TC and LDL-C were noted. Mean blood TC, LDL-C and glucose concentrations decreased significantly over time (P < 0.05), and differences in TC and LDL-C persisted after accounting for baseline differences (P < 0.0001). No significant differences between groups with time, or by gender, were noted in these variables. However, with regard to race, the significant reduction in TC and LDL-C concentration over time was noted in the African-American, but not Caucasian children (both P < 0.001).

Conclusions

Our intervention was effective in increasing the health knowledge of middle school children. It was also effective in decreasing soft drink consumption and increasing vegetable intake as compared with the control school. Other school-based health interventions have had mixed results. (14,24-26) The Know Your Body (KYB) study evaluated the effects of a teacher-delivered health education curriculum over a 5-year period in two samples of New York schools. The investigators reported a statistical difference in total serum cholesterol levels in one sample, but no changes in the other sample. In contrast to the KYB, our intervention used health care professionals to provide the education, with the hypothesis that outside sources may be a more effective influence on health-related learning than the typical classroom instructors. In addition, the Cardiovascular Health in Children study (27) examined classroom-based versus risk-based intervention in North Carolina children. The investigators demonstrated that the classroom-based approach was more effective in improving cardiovascular health, even with a short-term intervention of 8 weeks. While the classroom-based group did demonstrate a statistically significant decrease in cholesterol compared with the control group, there were no significant changes seen in blood pressure. In contrast to our study, the majority of the students in this investigation were Caucasian (eg, 77%). Our study was designed as a 16-week intervention in a racially diverse, rural school, which suggests that different approaches may be needed to modify health-related behaviors in racially diverse students in rural areas. Our investigation, similar to other studies, only involved a portion of the school's students. Future initiatives should be longer in duration, sustainable, involve all children and teachers in the school, target the social environment, and include behavior modification principles.

One strength of this investigation was the inclusion of a control school, which is particularly important when conducting a study of this kind. An additional strength is the creation of a multidisciplinary team used to effectively educate students. We felt that utilizing this team to actually measure metabolic parameters in the children would provide a lasting impression among them that would enhance awareness.

This investigation has several limitations. Specifically, while both our middle schools were racially diverse, they differed in the exact distribution of children among racial groups. The schools were chosen for their diversity, geographic proximity, and similar socioeconomic levels, but it would have been ideal to have more racially matched schools. A second limitation is that physical activity was not addressed. The school was unable to afford a physical education teacher during the time of the investigation, but as a result of our needs assessment, did incorporate physical activity in the curriculum in the year subsequent to our intervention.

Based upon the results of this investigation, several additional suggestions could be made for the design of future school-based health intervention projects in this rural population.

* Select schools in which the administration demonstrates not only a willingness to participate, but also a demonstrated interest in the study outcomes.

* Teacher support is critical; our high participation rate is evidence of excellent teacher support for the project.

* Increase contact with parents and school administrators, so that classroom lessons may be fully integrated into the home and the school environment. Parents, particularly mothers, are identified by children as their most important role models. (33)

* Work more intensively with the school foodservice director to improve the availability of heart-healthy foods (eg, fruits, vegetables, whole grains) in the school cafeteria, while being sensitive to budgetary constraints. Children may improve their knowledge of the importance of making healthful food choices but if these foods are not readily available at school and at home, this knowledge cannot be put into practice.

In conclusion, efforts to reduce childhood obesity and metabolic risk factors for CVD are urgently needed. Childhood obesity has become a significant healthcare concern in the US, and this study confirms that obesity and other metabolic risk factors are prevalent in children as young as ten years of age. The school environment provides an excellent opportunity for intervention, given that most children will spend a significant portion of their time in the school setting, and they will consume one or more meals and snacks per day while at school. We have described our experience with a pilot project aimed to educate middle-school aged children about better nutrition, physical activity, and ways to reduce their risk of CVD. We found that while small-scale interventions may provide some improvement in health awareness, more comprehensive interventions are needed for maximum benefit. Information obtained during this investigation has now been used to aid in the design of future school-based interventions in other rural areas of Mississippi.

Acknowledgments

The authors would like to thank Lindsay Batte, Laura Hope Sims, Chad Patel, Hal Dillon, Bobby Owens, Melissa Smith, and Andy Sistrunk for their assistance with data collection and entry, and Marion Wofford MD, Cindy Noble PharmD, Mrs. Sonda Johnson, Mrs. Crystal Whitfield, and the University of Mississippi Medical Center Department of Pediatrics for their support of this project.

References

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2. Muntner P, He J, Cutler JA, et al. Trends in blood pressure among children and adolescents. Jama 2004;291(17):2107-2113.

3. Wang G. Dietz WH. Economic burden of obesity in youths aged 6 to 17 years: 1979-1999. Pediatrics 2002;109:E81-81.

4. Freedman DS, Khan LK, Dietz WH, et al. Relationship of childhood obesity to coronary heart disease risk factors in adulthood: the Bogalusa Heart Study. Pediatrics 2001;108:712-718.

5. Nicklas TA, von Duvillard SP, Berenson GS. Tracking of serum lipids and lipoproteins from childhood to dyslipidemia in adults: the Bogalusa Heart Study. Int J Sports Med 2002;23 (Suppl 1):S39-43.

6. Guidelines for Blood Pressure Percentiles. National Heart, Lung, and Blood Institute. Available at: http://www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.htm. Accessed April, 2004.

7. Fagot-Campagna A, Pettitt DJ, Engelgau MM, et al. Type 2 diabetes among North American children and adolescents: an epidemiologic review and a public health perspective. J Pediatr 2000;136:664-672.

8. Barlow SE, Dietz WH. Obesity evaluation and treatment: Expert Committee recommendations. The Maternal and Child Health Bureau, Health Resources and Services Administration and the Department of Health and Human Services. Pediatrics 1998;102:E29.

9. Krauss RM, Eckel RH, Howard B, et al. AHA Dietary Guidelines: revision 2000: A statement for healthcare professionals from the Nutrition Committee of the American Heart Association. Circulation 2000;102:2284-2299.

10. Savoca MR, Evans CD, Wilson ME, et al. The association of caffeinated beverages with blood pressure in adolescents. Arch Pediatr Adolesc Med 2004;158:473-477.

11. Mississippi Rural Health Care Plan. Jackson, MS: Mississippi State Department of Health; 1999.

12. US Department of Health and Human Services. Tracking Healthy People 2010. Washington, DC: Government Printing Office; 2000.

13. Berenson GS. Bogalusa Heart Study: a long-term community study of a rural biracial (Black/White) population. Am J Med Sci 2001;322:293-300.

14. Dwyer JT, Stone EJ, Yang M, et al. Prevalence of marked overweight and obesity in a multiethnic pediatric population: findings from the Child and Adolescent Trial for Cardiovascular Health (CATCH) study. J Am Diet Assoc 2000;100:1149-1156.

15. Ogden CL, Flegal KM, Carroll MD, et al. Prevalence and trends in overweight among US children and adolescents, 1999-2000. Jama 2002;288:1728-1732.

16. Williams CL, Carter BJ, Eng A. The "Know Your Body" program: a developmental approach to health education and disease prevention. Prev Med 1980;9:371-383.

17. Kuczmarski RJ, Ogden CL, Grummer-Strawn LM, et al. CDC growth charts: United States. Adv Data 2000;314:1-27.

18. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. NIH Pulication No. 98-4083 ed: US Department of Health and Human Services, Public Health Service, National Institute of Health, National Heart, Lung and Blood Institute; 1998.

19. Higgins PB, Gower BA, Hunter GR, et al. Defining health-related obesity in prepubertal children. Obes Res 2001;9:233-240.

20. Ludwig DS, Peterson KE, Gortmaker SL. Relation between consumption of sugar-sweetened drinks and childhood obesity: a prospective, observational analysis. Lancet 2001;357:505-508.

21. Position of the American Dietetic Association: dietary guidance for healthy children aged 2 to 11 years. J Am Diet Assoc 1999;99:93-101.

22. Dennison BA, Jenkins PL, Rockwell HL. Development and validation of an instrument to assess child dietary fat intake. Prev Med 2000;31:214-224.

23. American Academy of Pediatrics. Committee on Nutrition. Cholesterol in childhood. Pediatrics 1998;101:141-147.

24. Warren JM, Henry CJ, Lightowler HJ, et al. Evaluation of a pilot school programme aimed at the prevention of obesity in children. Health Promot Int 2003;18:287-296.

25. Sahota P, Rudolf MC, Dixey R, et al. Randomised controlled trial of primary school based intervention to reduce risk factors for obesity. BMJ 2001;323:1029-1032.

26. Walter HJ, Hofman A, Vaughan RD, et al. Modification of risk factors for coronary heart disease. Five-year results of a school-based intervention trial. N Engl J Med 1988;318:1093-1100.

27. Harrell JS, McMurray RG, Gansky SA, et al. A public health vs a risk-based intervention to improve cardiovascular health in elementary school children: the Cardiovascular Health in Children Study. Am J Public Health 1999;89:1529-1535.

Holiness is doing God's will with a smile.
--Mother Teresa

T. Kristopher Harrell, PHARMD, Brenda M. Davy, PHD, RD, Jimmy L. Stewart, MD, and Deborah S. King, PHARMD

From the School of Pharmacy and the Department of Medicine, Division of Hypertension, University of Mississippi Medical Center, Jackson, MS, and the Department of Human Nutrition, Foods and Exercise, Virginia Polytechnic Institute and State University, Blacksburg, VA.

Reprint requests to T. Kristopher Harrell, PharmD, School of Pharmacy, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216. Email: [e-mail]

Accepted June 8, 2005.

Financial support was provided by Pfizer Pharmaceuticals.

RELATED ARTICLE: Key Points

* Children in rural areas of the southeast are at increased risk for overweight and obesity.

* Health awareness and dietary behavior is poor in these children.

* Simple interventions and partnerships between education and health systems can be beneficial in increasing school health.

* Comprehensive school-based interventions are needed for maximum effectiveness.

Table 1. Physical characteristics of middle school-aged children before
and after the 16-week intervention (a,b)

                                Intervention (n = 102)
                              Initial              Final

Height (cm) (c,d)             148 [+ or -] 11      151 [+ or -] 10
Weight (kg) (c)                51.5 [+ or -] 17.7   53.2 [+ or -] 18.2
BMI (kg/[m.sup.2]) (c,d)       22.7 [+ or -] 5.4    22.7 [+ or -] 5.6
BMI percentile, % of sample
  [greater than or equal to]   31%                  31%
  95th percentile
  [greater than or equal to]   24%                  21%
  85 but < 95th percentile
Body fat % (c,d)               27 [+ or -] 12       26 [+ or -] 11
Waist circumference (cm) (c)   73 [+ or -] 14       75 [+ or -] 14

                                   Control (n = 84)
                              Initial              Final

Height (cm) (c,d)             145 [+ or -] 9       151 [+ or -] 8
Weight (kg) (c)                49.0 [+ or -] 20.3   51.3 [+ or -] 21.2
BMI (kg/[m.sup.2]) (c,d)       23.0 [+ or -] 7.8    21.8 [+ or -] 7.5
BMI percentile, % of sample
  [greater than or equal to]   32%                  29%
  95th percentile
  [greater than or equal to]   17%                  15%
  85 but < 95th percentile
Body fat % (c,d)               28 [+ or -] 13       24 [+ or -] 12
Waist circumference (cm) (c)   72 [+ or -] 16       73 [+ or -] 17

(a) BMI, body mass index
(b) Data are mean [+ or -] SD.
(c) Significant difference over time, P < 0.05.
(d) Significant difference in intervention vs. control school, P < 0.05.

Table 2. Dietary intake of middle school-aged children before and after
the 16-week intervention (a)

                                 Intervention (n = 97)
                               Initial              Final

Energy (kcals) (b)             1811 [+ or -] 697    1749 [+ or -] 615
Fat (g) (b)                      67 [+ or -] 30       69 [+ or -] 27
  % (b,c)                        33 [+ or -] 6        35 [+ or -] 6
Protein (g)                      64 [+ or -] 27       65 [+ or -] 26
  %                              14 [+ or -] 4        15 [+ or -] 4
Carbohydrate (g)                242 [+ or -] 101     223 [+ or -] 82
  %                              53 [+ or -] 7        52 [+ or -] 13
Saturated fat (g) (b)            23 [+ or -] 11       24 [+ or -] 10
  %                              11 [+ or -] 2        12 [+ or -] 3
Polyunsaturated fat (g)          13 [+ or -] 7        12 [+ or -] 6
  %                               6 [+ or -] 2         6 [+ or -] 2
Monounsaturated fat (g) (b,c)    27 [+ or -] 12       27 [+ or -] 11
  % (b,c)                        13 [+ or -] 3        14 [+ or -] 3
Cholesterol (mg) (b)            169 [+ or -] 100     146 [+ or -] 27
Sodium (mg)                    3169 [+ or -] 1275   3060 [+ or -] 1248
Dietary fiber (g) (b)            13 [+ or -] 6        11 [+ or -] 5
  (g/1000 kcal) (b)               7.4 [+ or -] 3.1     6.6 [+ or -] 2.3
Calcium (mg)                    794 [+ or -] 380     803 [+ or -] 413
Fruit servings                    0.9 [+ or -] 1.1     0.8 [+ or -] 0.9
Vegetables servings (c)           0.5 [+ or -] 0.7     0.6 [+ or -] 0.8
Soft drinks (fl. oz.) (c)         7.2 [+ or -] 9.8     5.2 [+ or -] 7.0
Caffeine (mg) (b)                36 [+ or -] 41       32 [+ or -] 41
Breakfast consumption (d)         1.4 [+ or -] 0.5     1.4 [+ or -] 0.5

                                    Control (n = 75)
                               Initial              Final

Energy (kcals) (b)             2046 [+ or -] 767    1892 [+ or -] 695
Fat (g) (b)                      85 [+ or -] 42       72 [+ or -] 32
  % (b,c)                        36 [+ or -] 7        33 [+ or -] 6
Protein (g)                      76 [+ or -] 31       70 [+ or -] 29
  %                              16 [+ or -] 6        15 [+ or -] 4
Carbohydrate (g)                250 [+ or -] 98      246 [+ or -] 95
  %                              49 [+ or -] 9        52 [+ or -] 8
Saturated fat (g) (b)            30 [+ or -] 13       26 [+ or -] 13
  %                              13 [+ or -] 3        12 [+ or -] 3
Polyunsaturated fat (g)          15 [+ or -] 12       13 [+ or -] 7
  %                               6 [+ or -] 3         6 [+ or -] 2
Monounsaturated fat (g) (b,c)    34 [+ or -] 17       27 [+ or -] 13
  % (b,c)                        14 [+ or -] 3        13 [+ or -] 3
Cholesterol (mg) (b)            264 [+ or -] 207     156 [+ or -] 25
Sodium (mg)                    3304 [+ or -] 1436   3324 [+ or -] 1464
Dietary fiber (g) (b)            13 [+ or -] 6        11 [+ or -] 5
  (g/1000 kcal) (b)               6.8 [+ or -] 2.6     6.0 [+ or -] 2.6
Calcium (mg)                    856 [+ or -] 349     854 [+ or -] 404
Fruit servings                    0.8 [+ or -] 1.0     0.9 [+ or -] 0.8
Vegetables servings (c)           0.6 [+ or -] 0.7     0.4 [+ or -] 0.6
Soft drinks (fl. oz.) (c)         6.3 [+ or -] 9.1     7.6 [+ or -] 9.6
Caffeine (mg) (b)                24 [+ or -] 40       26 [+ or -] 35
Breakfast consumption (d)         1.2 [+ or -] 0.4     1.2 [+ or -] 0.5

(a) Data are mean [+ or -] SD.
(b) Significant difference over time, P < 0.05.
(c) Significant difference in intervention vs. control school over
time, P < 0.05.
(d) Scored as 1 = breakfast consumed, 2 = no breakfast consumed.

Table 3. Metabolic risk factors of middle school-aged children before
and after the 16-week intervention (a,b)

                                    Intervention (n = 105)
                                    Initial          Final

Resting blood pressure (mm Hg)
Systolic (c)                        110 [+ or -] 11  106 [+ or -] 10
  [greater than or equal to]         12%               3%
    95th percentile
  [greater than or equal to]          4%               3%
    85 but < 95th percentile
Diastolic (c)                        69 [+ or -] 11   65 [+ or -] 8
  [greater than or equal to]          8%               5%
    95th percentile
  [greater than or equal to]          4%               1%
    85 but < 95th percentile
Blood lipid concentrations (mg/dL)
Total cholesterol (c)               155 [+ or -] 32  145 [+ or -] 30
  [greater than or equal to]          8%               4%
    95th percentile
  [greater than or equal to]         21%              13%
    85 but < 95th percentile
HDL-C                                49 [+ or -] 12   47 [+ or -] 12
LDL-C (c)                            80 [+ or -] 26   72 [+ or -] 24
  [greater than or equal to]          6%               3%
    95th percentile
  [greater than or equal to]          9%               4%
    85 but < 95th percentile
Triglycerides                       130 [+ or -] 94  132 [+ or -] 86
Blood glucose concentrations         97 [+ or -] 14   88 [+ or -] 12
    (mg/dL) (c)

                                      Control (n = 84)
                                    Initial          Final

Resting blood pressure (mm Hg)
Systolic (c)                        107 [+ or -] 12  102 [+ or -] 13
  [greater than or equal to]          8%               7%
    95th percentile
  [greater than or equal to]          7%               4%
    85 but < 95th percentile
Diastolic (c)                        68 [+ or -] 9    65 [+ or -] 10
  [greater than or equal to]          8%               8%
    95th percentile
  [greater than or equal to]          8%               1%
    85 but < 95th percentile
Blood lipid concentrations (mg/dL)
Total cholesterol (c)               163 [+ or -] 25  155 [+ or -] 27
  [greater than or equal to]         11%               6%
    95th percentile
  [greater than or equal to]         27%              22%
    85 but < 95th percentile
HDL-C                                52 [+ or -] 10   51 [+ or -] 12
LDL-C (c)                            87 [+ or -] 23   78 [+ or -] 26
  [greater than or equal to]          7%               7%
    95th percentile
  [greater than or equal to]         14%               6%
    85 but < 95th percentile
Triglycerides                       126 [+ or -] 74  133 [+ or -] 73
Blood glucose concentrations         97 [+ or -] 21   93 [+ or -] 15
    (mg/dL) (c)

(a) Data are mean [+ or -] SEM.
(b) HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density
lipoprotein cholesterol.
(c) Significant difference over time, P < 0.05.
(d) Significant difference in intervention vs. control school with time,
P < 0.05.