The "Know Your Body" program: a developmental approach to health education and disease prevention

Measurement of human energy expenditure, with particular reference to field studies: an historical perspective

Over the years, techniques for the study of human movement have ranged in complexity and precision from direct observation of the subject through activity diaries, questionnaires, and recordings of body movement, to the measurement of physiological responses, studies of metabolism and indirect and direct calorimetry. This article reviews developments in each of these domains. Particular reference is made to their impact upon the continuing search for valid field estimates of activity patterns and energy expenditures, as required by the applied physiologist, ergonomist, sports scientist, nutritionist and epidemiologist. Early observers sought to improve productivity in demanding employment. Direct observation and filming of workers were supplemented by monitoring of heart rates, ventilation and oxygen consumption. Such methods still find application in ergonomics and sport, but many investigators are now interested in relationships between habitual physical activity and chronic disease. Even sophisticated questionnaires still do not provide valid information on the absolute energy expenditures associated with good health. Emphasis has thus shifted to use of sophisticated pedometer/accelerometers, sometimes combining their output with GPS and other data. Some modern pedometer/accelerometers perform well in the laboratory, but show substantial systematic errors relative to laboratory reference criteria such as the metabolism of doubly labeled water when assessing the varied activities of daily life. The challenge remains to develop activity monitors that are sufficiently inexpensive for field use, yet meet required accuracy standards. Possibly, measurements of oxygen consumption by portable respirometers may soon satisfy part of this need, although a need for valid longer term monitoring will remain.

Efficacy of a school-based childhood obesity intervention program in a rural southern community: TEAM Mississippi Project

A healthy lifestyle school-based obesity intervention was evaluated in a rural southern community where the rate of obesity ranks as the highest. School-age children (N = 450) ranging from 6 to 10 years of age (Mage = 8.34) participated in monthly physical activity and nutritional events during a 9-month academic year. The children's nutritional knowledge, number of different physical activities, fitness level, dietary habits, waist circumference, BMI percentile, and percentage body fat were measured pre- and postintervention. Changes on these measures were compared to students in a school employing the school system's standard health curriculum. Regression analyses with residualized change scores revealed that the intervention school showed statistically significant improvement in percentage body fat, physical activity, performance on fitness tests, and dietary habits compared to the control school. There was no evidence of differences in outcomes based on gender or ethnicity/race. With rates of obesity and overweight reaching 50% in southern rural communities, intervening early in development may offer the best outcome because of the difficulties with changing lifestyle behaviors later in adulthood. A population-based approach is recommended over a targeted approach to cultivate a culture of healthy lifestyle behaviors when children are developing their health-care habits. Evidence suggests that both boys and girls, and African-American and white children can benefit equally from such interventions.

Contributions of Ernst L. Wynder to chronic disease control worldwide and to preventive medicine

Ernst L. Wynder is internationally known for his important discoveries in the field of human chronic disease causation, that is the underlying mechanisms, studied in various animal models, as a foundation for recommendations on the prevention of these diseases. These include coronary heart disease, and the main human cancers including cancer of the lung, caused by traditional smoking habits, and the nutritionally linked cancers, namely cancer of the breast, prostate, colon, pancreas, and urinary bladder. Much of this research was performed in a chronic disease prevention institution--created by Dr. Wynder--the American Health Foundation. There were outreach programs to educate people about proper lifestyles to secure disease prevention, including beginning health education in children.

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.

Body Weight Status, Dietary Habits, and Physical Activity Levels of Middle School-aged Children in Rural Mississippi

OBJECTIVES

Obesity and cardiovascular diseases are more prevalent in the Southeast as compared with other geographic regions of the United States. However, few investigations have addressed health disparities among children in rural Southeastern areas. The purpose of this investigation was to determine the risk of overweight and obesity in middle school-aged children residing in a racially diverse rural community, and to characterize their dietary and physical activity habits.

METHODS

Two hundred and five middle school children from Scott County, Mississippi were enrolled in this investigation. Measurements included height, weight, body mass index, dietary intake using a 24-hour recall, and physical activity level using pedometers.

RESULTS

Of the 205 children studied, 54% were "overweight" or "at risk for overweight" according to a body mass index-for-age sex-specific percentile. Intake of saturated fat and sodium exceeded recommended levels, whereas intake of calcium, fruits, and vegetables was inadequate. One third of the sample consumed 12 fluid ounces or more of soda on the day of the recall. Physical activity level was below that previously reported for children in this age range, and knowledge of the importance of diet and physical activity in the prevention of cardiovascular disease was poor, particularly among African-American children.

CONCLUSIONS

The children in our sample are at increased risk for overweight and obesity. Factors that may be targeted for intervention include a reduction in dietary intake of fat, saturated fat, sodium, and soft drinks, and an increased intake of fruits and vegetables. Physical activity should be encouraged. Many of these factors could be improved through changes within the school environment.

Effects of 2 prevention programs on high-risk behaviors among African American youth: a randomized trial

OBJECTIVE

To test the efficacy of 2 programs designed to reduce high-risk behaviors among inner-city African American youth.

DESIGN

Cluster randomized trial.

SETTING

Twelve metropolitan Chicago, Ill, schools and the communities they serve, 1994 through 1998.

PARTICIPANTS

Students in grades 5 through 8 and their parents and teachers.

INTERVENTIONS

The social development curriculum (SDC) consisted of 16 to 21 lessons per year focusing on social competence skills necessary to manage situations in which high-risk behaviors occur. The school/community intervention (SCI) consisted of SDC and school-wide climate and parent and community components. The control group received an attention-placebo health enhancement curriculum (HEC) of equal intensity to the SDC focusing on nutrition, physical activity, and general health care.

MAIN OUTCOME MEASURES

Student self-reports of violence, provocative behavior, school delinquency, substance use, and sexual behaviors (intercourse and condom use).

RESULTS

For boys, the SDC and SCI significantly reduced the rate of increase in violent behavior (by 35% and 47% compared with HEC, respectively), provoking behavior (41% and 59%), school delinquency (31% and 66%), drug use (32% and 34%), and recent sexual intercourse (44% and 65%), and improved the rate of increase in condom use (95% and 165%). The SCI was significantly more effective than the SDC for a combined behavioral measure (79% improvement vs 51%). There were no significant effects for girls.

CONCLUSIONS

Theoretically derived social-emotional programs that are culturally sensitive, developmentally appropriate, and offered in multiple grades can reduce multiple risk behaviors for inner-city African American boys in grades 5 through 8. The lack of effects for girls deserves further research.

Changes in common activities of 3rd through 10th graders: the CHIC study

PURPOSE

This study was a longitudinal examination of the change in both the activities done and the intensity of those activities from childhood to adolescence.

METHODS

Common activities were assessed by questionnaire initially on 656 subjects from 21 elementary schools; 50.5% were female, 83.4% were Caucasian, 20.6% African-American, and 6.0% were other races.

RESULTS

Girls more often reported sedentary activities overall. Weighted least squares analyses showed boys consistently reported more vigorous activities than girls (P < 0.0008). African-American girls reported fewer vigorous activities than Caucasian or other race girls (P = 0.027). Sedentary activities were more frequently reported with increasing age (X2 P < 0.001). The youngest African-American and Caucasian boys reported similar activity patterns. However, boys from other races reported more intense activities until sixth and seventh grades when African-American boys began reporting more sedentary activities than Caucasians or other races (P = 0.004). During sixth-eighth grades, Generalized Estimating Equations (GEE) models show that girls with more advanced pubertal status reported more sedentary activities than girls who were less developed (P < 0.0001). For high school girls, race was a marginally significant predictor (P = 0.05) of activity status. Neither race nor pubertal status were significant factors in activities chosen by middle school boys. However, for male high school students, Caucasians were more likely than African-Americans to report vigorous activities (P = 0.005).

CONCLUSIONS

Variation in activities by race within gender suggests that establishing activity patterns in youth may be race-specific as well as gender-specific and must be accounted for in designing physical activity interventions. Also, pubertal maturation is a factor in activity choices in middle school girls.

A public health vs a risk-based intervention to improve cardiovascular health in elementary school children: the Cardiovascular Health in Children Study

OBJECTIVES

This study sought to determine the population effects of both classroom-based and risk-based interventions designed to reduce cardiovascular disease risk factors in children.

METHODS

Elementary school children (n = 2109; age range: 7-12 years) were randomized by school to a classroom-based intervention for all third and fourth graders, a risk-based intervention only for those with 1 or more cardiovascular disease risk factors, or a control group. The 8-week interventions involved both knowledge--attitude and physical activity components.

RESULTS

School-level analyses showed that physical activity in the risk-based group and posttest knowledge in the classroom-based group were significantly higher than in the control group. With regard to trends shown by individual-level analyses, cholesterol dropped more in the classroom-based than in the control group, and skinfold thickness decreased 2.9% in the classroom-based group and 3.2% in the risk-based group (as compared with a 1.1% increase in the control group).

CONCLUSIONS

Both classroom-based and risk-based interventions had positive effects on physical activity and knowledge, with trends toward reduced body fat and cholesterol. However, the classroom-based approach was easier to implement and evidenced stronger results than the risk-based intervention.

Evaluation of a health and nutrition education program in primary school children of Crete over a three-year period

BACKGROUND

No national policy for health education in schools exists to date in Greece. The first attempt to apply a school-based health education intervention program was launched in 1992 on all 4,171 pupils registered in the first grade in two counties of Crete. The 1,510 pupils registered in a third county served as controls.

METHODS

The school-based intervention and the seminars organized for parents were primarily aimed at improving children's diet, fitness, and physical activity. Pupils in the first grade in a representative sample of 40 schools were examined prior to the intervention program on a variety of health knowledge, dietary, physical activity, fitness, anthropometric, and biochemical indices. The same measurements were taken after 3 years of the program on 288 intervention group and 183 control group pupils.

RESULTS

Positive serum lipid level changes occurred to a greater extent in the intervention group than the control group. BMI increased less in the intervention group than for controls. The increase in health knowledge and physical activity and fitness levels occurred to a higher extent in the intervention group compared to controls.

CONCLUSIONS

The short-term changes observed in the present study are markedly encouraging and indicate great potential for progressive improvement. Continuation and expansion of such a program may prove to be beneficial in initiating long-term changes.

School-based interventions improve heart health in children with multiple cardiovascular disease risk factors

OBJECTIVE

To determine the immediate effects of two types of elementary school-based interventions on children with multiple cardiovascular disease (CVD) risk factors.

DESIGN

Randomized, controlled field trial.

SETTING

Conducted in 18 randomly selected elementary schools across North Carolina.

STUDY PARTICIPANTS

Four hundred twenty-two children age 9 +/- 0.8 years with at least two risk factors at baseline: low aerobic power and either high serum cholesterol or obesity.

INTERVENTION

Both 8-week interventions consisted of a knowledge and attitude program and an adaptation of physical education. The classroom-based intervention was given by regular teachers to all children in the 3rd and 4th grades. The risk-based intervention was given in small groups only to children with identified risk factors. Children in the control group received usual teaching and physical education.

OUTCOME MEASURES

The primary outcome measure was cholesterol; additional measures were blood pressure, body mass index, body fat, eating and activity habits, and health knowledge.

RESULTS

Both interventions produced large reductions in cholesterol (-10.1 mg/dL and -11.7 mg/dL) compared with a small drop (-2.3 mg/dL) in the controls. There was a trend for systolic blood pressure to increase less in both intervention groups than in the controls. Both intervention groups had a small reduction in body fat and higher health knowledge than the control group.

CONCLUSIONS

Both brief interventions can improve the CVD risk profile of children with multiple risk factors. The classroom-based approach was easier to implement and used fewer resources. This population approach should be considered as one means of early primary prevention of CVD.

Healthy Start: a comprehensive health education program for preschool children

BACKGROUND

Healthy Start is a 3-year demonstration and education research project designed to evaluate the effectiveness of a multidimensional cardiovascular (CV) risk reduction intervention in preschool centers over a 3-year period of time.

METHODS

Two primary interventions are employed. The first is the preschool food service intervention program designed to reduce the total fat in preschool meals and snacks to less than 30% of calories and reduce the saturated fat to less than 10% of calories. The second major intervention is a comprehensive preschool health education curriculum, focused heavily on nutrition.

RESULTS

Effectiveness of the intervention will be determined through evaluation of changes in dietary intake of preschool children at school meals and snacks, especially with respect to intake of total and saturated fat. Evaluation of the education component will include assessment of program implementation by teachers, assessment of changes in nutrition knowledge by preschool children, and assessment of changes in home meals that children consume (total and saturated fat content). Blood cholesterol will be evaluated semiannually to evaluate changes that may be due to modification of dietary intake. Growth and body fatness will also be assessed.

CONCLUSIONS

While substantial efforts have targeted CV risk reduction and health education for elementary school children, similar efforts aimed at preschool children have been lacking. The rationale for beginning CV risk reduction programs for preschool children is based upon the premise that risk factors for heart disease are prevalent by 3 years of age and tend to track over time, most commonly hypercholesterolemia and obesity, both related to nutrition. Since the behavioral antecedents for nutritional risk factors begin to be established very early in life, it is important to develop and evaluate new educational initiatives such as Healthy Start, aimed at the primary prevention of cardiovascular risk factors in preschool children. The purpose of this publication is to describe the rationale and methods for the Healthy Start project.

Leisure time activities of elementary school children

The three most common leisure time activities of 2,200 third and fourth grade children (mean age 8.8 + 0.8; 50.7% girls) and the association of the intensity levels of those activities with demographic variables and risk factors for cardiovascular disease are reported. Activities reported most often by boys were playing video games (33%), playing football (32%), bicycling (31%), watching television (28%), and playing basketball (26%). The girls reported doing homework (39%), bicycling (31%), watching television (30%), dancing (27%), and reading (23%). Overall, the children, especially girls, reported fairly sedentary activities, with an average metabolic equivalent level of 4.2 for girls and 4.8 for boys. Among boys, African Americans reported more vigorous activities than Whites, but the activities reported by White girls were somewhat more vigorous than those reported by non-White girls. Children from a higher socioeconomic status (SES), especially boys, reported a greater proportion of sedentary activities than lower SES children. The risk factors of cholesterol, blood pressure, skinfold thickness, and body mass index were not significantly associated with total activity score. However, significantly more nonobese than obese children reported a vigorous (high-intensity) activity as one of their top three activities.

Effects of an obesity prevention program on the eating behavior of African American mothers and daughters

Cardiovascular disease (CVD) is the number one cause of death in the United States. Obesity is highly related to CVD risk, especially in African American women. This study explored the efficacy of a culturally specific obesity prevention program. Designed for low-income, inner-city African American girls and their mothers, the program addressed the importance of eating a low-fat, low-cholesterol diet and increasing activity. Mother-daughter dyads were randomly assigned to a 12-week treatment or an attention placebo group. Participants were assessed at pre- and posttreatment on dietary intake, including daily fat intake, daily saturated fat intake, percentage of daily calories from fat, and daily cholesterol intake. Results showed significant differences between the treatment and control mothers for daily saturated fat intake and percentage of calories from fat. Differences among treatment and control groups were also noted for the daughters on percentage of daily calories from fat. Implications of the findings for developing culturally specific health risk reduction programs are discussed.

Prevention of substance use problems: models, factors, and processes

The use of substances for medical or nonmedical reasons occurs in most cultures. Regardless of the reason for use, however, most types of substance use (or drug-taking behaviors) have their associated problem states. The prevention of substance use problems is an important issue and need in every society. In this review we present and discuss various models and factors that purport to describe and predict patterns of drug use, and we discuss various strategies to prevent the occurrence of substance use problems.

Evaluation of interventions to improve solar protection in primary schools

Childhood and adolescence are critical periods in the etiology of subsequent melanoma and nonmelanocytic skin cancers. The aims of the study were (a) to develop a valid measure of solar protection in 9 to 11-year-old school students, (b) to evaluate the differential effectiveness of two interventions aimed at changing solar protection in this age group, and (c) to identify the predictors of use of a high level of solar protection. A Solar Protection Behavior Diary was developed and validated during a pilot, after which 11 schools were randomly allocated to one of three groups: intensive intervention (247 students), standard intervention (180 students), or control (185 students), with students in years 5 and 6 participating in the study. Students completed the validated diary (for 5 days) and a knowledge and attitudes questionnaire at pretest and at two posttest periods (4 weeks and 8 months after pretest). Results indicated that students in the intensive intervention group were significantly more likely to have used a high level of protection at both posttest periods compared to the control and standard intervention groups. There was no difference in the protection level of the control and standard intervention groups at either posttest, indicating that this minimal intervention was not effective in changing the solar protection behavior of the students. Students with a high level of solar protection at pretest were also significantly more likely to have a high level of protection at both posttest periods, and those with a greater number of opportunities to protect were less likely to protect at the second posttest.

A three-year evaluation of the know your body program in inner-city schoolchildren

The impact of the Know Your Body (KYB) comprehensive school health education program was evaluated in a sample of first through sixth-grade students from New York City, using two analytic strategies: a longitudinal cohort and a "posttest only" cohort. In both cohorts, program impact was examined between condition (i.e., KYB vs. no-treatment comparison group) as well as within condition (i.e., low, moderate, and high student exposure). Students in the longitudinal cohort (n = 1,209) who were exposed to high implementation teachers had significantly (p < .05) lower total plasma cholesterol and systolic blood pressure at 3-year posttest than comparison students. Students in the posttest only cohort (n = 3,066) who had high implementation teachers showed significantly (p < .05) lower total plasma cholesterol, systolic blood pressure, self-reported intake of meat and desserts, as well as higher health knowledge and self-reported intake of "heart healthy" foods and vegetables than comparison students. In both cohorts, program effects for several outcome variables were linearly related to level of student exposure to the curriculum, suggesting a dose-response effect. While several methodologic limitations may have influenced study outcomes, these data nonetheless appear to confirm that the KYB program can have a significant positive impact on the knowledge, behavior, and selected risk factors of students in primary grades and that efforts to disseminate and evaluate school health education programs should include strategies to monitor and enhance teacher implementation.

Relationships among children's health-related behaviors: a multivariate, developmental perspective

Considerable evidence documents the aggregation of cardiovascular risk factors in children; yet, very little is known about the covariation of children's health practices. Accordingly, using a multivariate and developmental perspective, the present research examines the interrelationships among multiple health behaviors (i.e., physical activity, eating habits, smoking, alcohol use, and stress-related behaviors) in 1,092 predominantly low-socioeconomic status, rural schoolchildren (ages 11-18, grades 6-12). Our data provide support for a multidimensional view of children's health habits and suggest that patterns of interrelationships may vary at different developmental levels. Implications of these results are discussed and directions for future research are highlighted.

Cardiovascular risk assessment in school-age children: a school and community partnership in health promotion

There is little doubt that the primary prevention of cardiovascular disease is a pediatric problem that nursing must address. Cardiovascular health-promotion activities for children have generally used an ecologic model, providing community-based education programs in the schools. The purpose of this study was to identify changes in cardiovascular risk among sixth-grade cohorts over eight years. Four variables known to be associated with such risk--weight (obesity), pulse rate recovery index, blood pressure, and total cholesterol level--were measured on 4900 students, and changes in their prevalence were analyzed. The data presented in this paper were compiled from a screening program conducted by a local health department in partnership with a school district's health-education program. Although the school-based health-education program has been in existence for eight years, the prevalence of cardiovascular risk in sixth-grade students has not declined, suggesting the need for nurses to target the children at risk, and address more directly the motivational and affective domains in addition to cognitively focused programs.

Assessing knowledge of cardiovascular health-related diet and exercise behaviors in Anglo- and Mexican-Americans

This article describes the Adult and Child Behavior Knowledge Scales that were used as part of the San Diego Family Health Project to measure knowledge of health behaviors related to cardiovascular diseases in two ethnic groups: Anglo- and Mexican-Americans. The psychometric characteristics of these scales indicate acceptable reliabilities for assessing knowledge of dietary sodium, dietary fat, and exercise among both adults and children and differ from other health knowledge scales in that they focus on "behavioral capability" rather than on the link between behavior and disease. It is believed that the type of information measured by our scales is more closely related to behavior changes sought in contemporary cardiovascular disease prevention trials. Results of ANOVA used to test differences in knowledge by ethnicity and sex indicate strong main effects for ethnicity among both children and adults. However, sex was not consistently related to knowledge, except for the general tendency of males to be more knowledgeable about exercise. Step-wise and simultaneous-entry multiple regression were used to test a subset of variables, including sex, education, self-efficacy, acculturation (for Mexican-Americans), and parental health knowledge (for children) as determinants of health knowledge. Education was the strongest predictor for Anglo-American adults, and acculturation level was the strongest for Mexican-American adults. Among children, the only statistically significant variable was parental acculturation level for Mexican-Americans. The scales were found to be useful in measuring differences in knowledge across cultural/linguistic groups and to clearly identify marginally acculturated Mexican-Americans as being least aware of health-behavior knowledge. Implications are discussed.

The advisability of the prudent diet in adolescence

Risk factor status for cardiovascular disease is affected by life style. Adolescence is a time during which long term life-style habits, including dietary habits, are established. Physicians who treat adolescent patients have a responsibility to be aware of the scientific evidence on the diet-heart question so that they can provide their patients with sound dietary advice. The American Heart Association has recommended that Americans consume a "prudent diet" in which daily consumption of cholesterol is no more than 300 mg with up to 30-35% of calories derived from fat, and less than 10% of calories derived from saturated fat and less than 10% from polyunsaturated fat. This paper reviews this recommendation with particular reference to studies of adolescents. This review centers around four main issues: 1) the estimated effect on serum cholesterol levels of a switch from the usual American diet to the prudent diet; 2) the effect of a predicted decrease in serum cholesterol on the risk of developing cardiovascular disease; 3) evaluation of the evidence of possible adverse effects of the prudent diet; 4) feasibility of the prudent diet. Based on a review of these four issues, the authors feel that the American Heart Association's prudent diet should be strongly recommended for all healthy adolescents.

Teaching children self-care for chronic disease prevention: obesity reduction and smoking prevention

A general health education program was developed for 1,252 students in six New York city area school districts. The purpose of the three-year project was to reduce the prevalence of risk factors associated with increased cardiovascular and cancer risk in adults. The curriculum included nutrition, antitobacco, and hypertension-control materials. A smaller, experimental intensive health behavior program was also developed for obese children (weight greater than or equal to 120% ideal for height, age, and sex). A smoking prevention program was offered to children with the aim of discouraging new smokers. Findings show that: 1) such a school-based primary disease prevention program is feasible and highly acceptable; and 2) reduction of obesity and new cigarette smoking occurred with intensive intervention involving small groups of students. On the other hand, a general health education itself had little effect in the total population in reducing the incidence of extreme clinical values (such as physical inactivity, high blood pressure, as well as smoking and obesity) for their age and sex. It is recommended that future programs for higher risk children concentrate on behavioral change rather than on general education.