Physical environmental correlates of childhood obesity: a systematic review

Increasing rates of childhood obesity in the USA and other Western countries are a cause for serious public health concern. Neighborhood and community environments are thought to play a contributing role in the development of obesity among youth, but it is not well understood which types of physical environmental characteristics have the most potential to influence obesity outcomes. This paper reports the results of a systematic review of quantitative research examining built and biophysical environmental variables associated with obesity in children and adolescents through physical activity. Literature searches in PubMed, PsychInfo and Geobase were conducted. Fifteen quantitative studies met the inclusion criteria for this systematic review. The majority of studies were cross-sectional and published after 2005. Overall, few consistent findings emerged. For children, associations between physical environmental variables and obesity differed by gender, age, socioeconomic status, population density and whether reports were made by the parent or child. Access to equipment and facilities, neighborhood pattern (e.g. rural, exurban, suburban) and urban sprawl were associated with obesity outcomes in adolescents. For most environmental variables considered, strong empirical evidence is not yet available. Conceptual gaps, methodological limitations and future research directions are discussed.

Relationship between DDE concentrations and laying sequence in eggs of two passerine species

Passerine eggs make useful biomonitors of environmental pollutants. Among passerines, it is not known whether organochlorine contaminants in eggs within the same clutch are independent observations or follow a laying order effect. Intraclutch variation of DDE (1,1-dichloro-2,2-bis[(p-chlorophenyl)]ethylene) concentrations was studied in eggs collected from prothonotary warblers (Protonotaria citrea) and European starlings (Sturnus vulgaris) nesting on National Priority List sites in lower Alabama and central Colorado, respectively. All 209 eggs collected for this study contained detectable levels of DDE. Mean concentration of DDE across all prothonotary warbler eggs (mean 8.71 microg/g +/- 1.19, n = 20) was almost two orders of magnitude greater than mean concentrations of DDE in all starling eggs (mean 0.70 microg/g +/- 0.06, n = 189). In both species, there was a large amount of variability among individual eggs of the same clutch and no significant relationship between laying order and DDE concentration. Variation among eggs laid in the same sequential order was high and effectively masked any potential trends in laying order effect. We hypothesized that the variability was caused by the spatial heterogeneity of DDE on our study sites, the nature of egg development within a female passerine, or a combination of these factors. Investigators focusing on lipophilic contaminants should exercise caution when making inferences about contaminant concentrations in an entire clutch of passerine eggs after the collection and analysis of a single egg because our data show that DDE levels in a single egg collected for analysis do not consistently reflect DDE levels in the eggs remaining in the nest.

Accumulation of DDT and mercury in prothonotary warblers (Protonotaria citrea) foraging in a heterogeneously contaminated environment

Foraging areas of adult prothonotary warblers (Protonotaria citrea) were determined using standard radiotelemetry techniques to determine if soil concentrations of p,p'dichlorodiphenyltrichloroethane (p,p'DDT) and mercury in foraging areas could be used to predict contaminant levels in diets and tissues of nestling warblers. Adult warblers were fitted with transmitters and monitored for approximately 2 d while foraging and feeding 6- to 8-d-old nestlings. Foraging ecology data were integrated with contaminant levels of soil, diets, and tissues into a comprehensive analysis of geographic variation in contaminant exposure and uptake using linear regression. Concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and mercury in nestling tissues varied considerably across the study site. Mean concentration of DDE was greater in eggs than all other tissues, with individual samples ranging from 0.24 to 8.12 microgram/kg. In general, concentrations of DDT in soil were effective in describing the variation of contaminants in adipose samples. Concentrations of mercury in soils accounted for 78% of the variation in kidney samples. This was the best relationship of any of the paired variables. All other relationships showed relatively poor predictive ability.

The RE-AIM framework for evaluating interventions: what can it tell us about approaches to chronic illness management?

BACKGROUND

The RE-AIM framework is used as a method of systematically considering the strengths and weaknesses of chronic illness management interventions in order to guide program planning.

METHOD

The RE-AIM dimensions of Reach, Efficacy, Adoption, Implementation, and Maintenance are used to rate one-on-one counseling interventions, group sessions, interactive computer-mediated interventions, telephone calls, mail interventions, and health system policies.

RESULTS

The RE-AIM ratings suggest that, although often efficacious for those participating, traditional face-to-face intervention modalities will have limited impact if they cannot be delivered consistently to large segments of the target population. Interventions using new information technologies may have greater reach, adoption, implementation, and maintenance, and thereby greater public health impact. Policy changes received high ratings across a variety of RE-AIM dimensions.

CONCLUSIONS

Program planners should make decisions regarding implementing and funding health services based on multiple dimensions, rather than only considering efficacy in randomized clinical trials. Doing so may improve the resulting public health impact. Directions for future chronic illness management research related to RE-AIM, and implications for decision making, are described.

Increasing the fruit and vegetable consumption of fourth-graders: results from the high 5 project

BACKGROUND

This study evaluated the effects of a school-based dietary intervention program to increase fruit and vegetable consumption among fourth-graders.

METHODS

Twenty-eight elementary schools were randomized to an immediate intervention condition or to a delayed intervention control condition. Measures of diet and psychosocial variables were collected at base line and 1 and 2 years post-baseline. The intervention included classroom, parent, and cafeteria components.

RESULTS

Mean daily consumption of fruit and vegetables was higher for the intervention children compared with controls at Follow-up 1 (X(t) = 3.96, X(c) = 2.28) and at Follow-up 2 (X(t) = 3.20, X(c) = 2.21). Macro- and micronutrient changes favoring the intervention children were also observed at both Follow-up 1 and Follow-up 2. Mean daily consumption of fruit and vegetables was higher for intervention parents compared with controls at Follow-up 1 (X(t) = 4.23,X(c) = 3.94) but not at Follow-up 2.

CONCLUSIONS

Strong effects were found for the High 5 intervention on fruit and vegetable consumption, on macro- and micro-nutrients, and on psychosocial variables. Future work is needed to enhance the intervention effects on parents' consumption and to test the effectiveness of the intervention when delivered by classroom teachers.

Methods, results, and lessons learned from process evaluation of the high 5 school-based nutrition intervention

This article describes the process evaluation of High 5, a school-based intervention targeting fruit and vegetable consumption among fourth graders and their families. The outcome evaluation involved 28 schools randomized to intervention or control conditions. The intervention included classroom, family, and cafeteria components. Process evaluation was completed on each of these components by using observations, self-report checklists, surveys, and other measures. Results indicated high implementation rates on the classroom activities. Moderate family involvement was attained, perhaps diminishing intervention effects on parent consumption. Cafeterias provided environmental cues, and fruit and vegetable offerings as directed by the program. A lower dose of the intervention was delivered to schools with larger African American enrollments and lower-income families. This article provides insights into the effective elements of a school-based dietary intervention and provides suggestions for process evaluation in similar studies.

Baseline fruit and vegetable intake among adults in seven 5 a day study centers located in diverse geographic areas

OBJECTIVE

To examine baseline rates of fruit and vegetable consumption among adults in the 5 A Day research trials in order to identify any regional and sociodemographic differences associated with daily servings.

DESIGN

The main outcome measure was the frequency of fruits and vegetables consumed within 1 month of the baseline survey as assessed by a 7-item food frequency questionnaire (FFQ).

SUBJECTS/SETTING

Participants (N = 15,060) were from 7 study centers. Study centers included schools (N = 48), worksites (N = 60), churches (N = 50), or the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) clinics (N = 15) in interventions to increase fruit and vegetable consumption.

STATISTICAL ANALYSES

Means and standard errors, adjusting for clusters, were calculated. A mixed linear model analyzed relationships between fruit and vegetable consumption and regional center, gender, age, race, education, income, marital status, food-shopping responsibility, and whether one lives with children.

RESULTS

Results indicate an overall mean intake of 3.6 daily servings of fruits and vegetables. Significant differences in mean daily servings were found among the regional study centers (low of 3.0 to high of 4.1). There were significant differences in mean daily consumption by age (< 30 years = 3.7 servings per day; 30 to 49 years = 3.4; > or = 50 years = 3.7), education (> high school = 3.4 servings per day; high school graduate = 3.4; some college = 3.5; college graduate = 3.9), race (black = 3.7 servings per day; Hispanic = 3.0; white = 3.6; other = 3.7), marital status (married = 3.6 servings per day; single = 3.5), and food-shopping responsibilities (little = 3.2 servings per day; about half = 3.6; most = 3.8). Only 17% of respondents ate 5 or more servings of fruits and vegetables per day.

CONCLUSIONS

The 7 regions showed significant variability in daily fruit and vegetable consumption, suggesting that a single national message to increase fruit and vegetable consumption may not reach the population segments most in need of changing. It is advisable to spend more time understanding the food consumption habits of the population under investigation to develop messages to foster behavior change.

Sociocultural determinants of physical activity among children

BACKGROUND

This study explores underresearched sociocultural predictors of children's physical activity and fitness, with particular attention paid to the influence of ethnicity independent from potential confounders such as social class.

METHODS

Utilizing a 1997/1998 cross-sectional sample of 107 children (ranging in age from 6.5 to 13 years, mean = 10 years) participating in a longitudinal study of childhood obesity in Birmingham, Alabama, predictors of television viewing, vigorous exercise, habitual physical activity, exercise in school P.E. classes, sports team participation, and maximal aerobic capacity were identified, utilizing multiple regression analyses.

RESULTS

The results indicated few ethnic differences in childhood physical activity once characteristics such as social class and single vs dual parent family background were controlled for. Specific multivariate findings included higher levels of television viewing and vigorous exercise among children from single parent homes; lower habitual physical activity among girls; less P.E. exercise among African Americans and children from single parent homes; higher sports team participation among older yet physically immature children; and higher physical fitness among boys, Caucasians, physically mature children, and children from single parent homes.

CONCLUSIONS

This study illustrates the multidimensional nature of childhood physical activity and the influence of sociocultural factors on children's activity patterns.

Stages of change for increasing fruit and vegetable consumption among adults and young adults participating in the national 5-a-Day for Better Health community studies

Higher fruit and vegetable consumption is associated with a reduced risk of certain cancers and chronic diseases. The 5-a-Day for Better Health community studies are evaluating population-based strategies to achieving dietary behavior change using the stages-of-change model and associated theories. The authors present baseline comparisons of stages of change for fruit and vegetable consumption among adults and young adults in eight study sites representing diverse regions of the United States and diverse populations and settings. Three dominant stages, precontemplation, preparation, and maintenance, were found across sites. Women and those with college degrees were more likely to be in action/maintenance. Fruit and vegetable consumption, self-efficacy, and knowledge of the 5-a-Day recommendation were positively associated with more advanced stages of change in all study sites. The authors discuss the findings in relation to possible limitations of this and other dietary stages-of-change measures and suggest directions for future research.

Patterns in child and adolescent consumption of fruit and vegetables: effects of gender and ethnicity across four sites

OBJECTIVES

Few studies have examined the association of gender and ethnicity with fruit and vegetable consumption. We examined these associations using baseline data from four school-based sites funded under the National Cancer Institute's 5 A Day for Better Health Program.

METHODS

Diet was measured using 24-hour recalls at three sites and seven-day food records at one site. Demographics were obtained via self-report or school records. Regression analyses for clustered data were employed with fruit and vegetables combined and fruit and vegetables separately.

RESULTS

Girls ate more fruit, more vegetables and more fruit and vegetables combined than boys at the Georgia site. Ethnicity was significant in two sites: In Georgia, African-Americans ate more fruit and more fruit and vegetables combined than European-Americans; in Minnesota, Asian-American/Pacific Islanders and African-Americans ate more fruit than European-Americans, and European-Americans and African-Americans ate more vegetables than Asian-Americans. No significant effects were found at the Alabama or Louisiana sites.

CONCLUSIONS

Ethnicity was related to fruit and vegetable consumption in Georgia and Minnesota. Consistent with prior studies, gender was related to fruit and vegetable consumption, with girls consuming more servings than boys; however, this was observed at one site only, Georgia. Consumption levels were similar to national estimates for children and varied by region. Further studies are needed using a single methodology to facilitate regional comparisons.

Role of physical activity in the prevention of obesity in children

The increasing prevalence of childhood obesity and its concomitant health risks justify widespread efforts toward prevention. Although both diet and physical activity have been emphasized as appropriate interventions, the current paper focuses on the role of physical activity in obesity prevention. Children's levels of physical activity are highly variable, and may be influenced by a multitude of factors including physiological, psychological, sociocultural and environmental determinants. Although the relationship between physical activity and obesity is controversial and the protective mechanism unclear, physical activity is hypothesized to protect individuals from the development of obesity by increasing energy expenditure and resting metabolic rate (RMR) and leading to a favourable fuel utilization. The beneficial effect of physical activity in children is supported by controlled exercise intervention programs. Several broad-based public health interventions designed to increase children's levels of physical activity have been implemented in schools, families and communities, with results suggesting promising strategies for the prevention of childhood obesity. It is likely that successful prevention of childhood obesity through physical activity promotion will involve theory-based, culturally appropriate school, family and community interventions. Through policy changes, environmental planning and educational efforts in schools and communities, increased opportunities and encouragement for physical activity can be provided.

Design of "High 5": a school-based study to promote fruit and vegetable consumption for reduction of cancer risk

BACKGROUND

This paper describes the methods used in "High 5," a school-based study to increase fruit and vegetable consumption for cancer risk reduction.

METHODS

Twenty-eight elementary schools were matched and randomized to intervention or control conditions. All students were assessed based on diet and psychosocial variables at baseline and one and two years post-baseline. The intervention included classroom, parent, and environmental components.

RESULTS

The study recruited 1,698 families and retained 85%. The two conditions were equivalent at baseline; 50% female students, 81% to 84% European-American students, and 2.9 servings of fruit and vegetables per day. Good completion was achieved across the intervention components (e.g., 90% of lessons taught, 72% of parent materials read, 3.6 servings of fruit and vegetables offered in cafeterias).

CONCLUSIONS

The use of school-based programs, with strong evaluation designs, will enhance knowledge about the modification of nutrition behavior and cancer risk in children. Lessons learned from the study are reported.

Recruitment issues in school-based research: lessons learned from the High 5 Alabama Project

School-based research requires a multi-level recruitment process to ensure an adequate sample. This article describes the High 5 Alabama recruitment experience at four levels; district, school, classroom and individual. One hundred percent of 28 schools across three districts and 108 classroom teachers contacted agreed to participate. Moderate success (69%) at the individual level, which required active parental consent for the student and parent to participate, resulted in 1,698 student/parent participants. An examination of differences between participants and nonparticipants revealed under-representation of a subsample of the population in the project sample. Suggestions obtained from project staff and teachers intended to enhance future school-based recruitment strategies include enlistment of a district advocate; meeting with teachers to solicit support; using incentives with students and teachers; direct contact with parents; having teachers keep rosters of students returning consent forms; and tailoring recruitment strategies for specific subpopulations.

Comparing two strategies to modify dietary behavior and serum cholesterol

AIM

To test the hypothesis that a strategy including cholesterol screening and dietary education is more effective than dietary education alone in changing dietary behavior and serum cholesterol levels.

METHODS

Individuals at four worksites were enrolled in a randomized trial with a 'full intervention' condition in which subjects were told their serum cholesterol value and also received a dietary change kit (n = 236), and a 'partial intervention' condition in which subjects received the same dietary change kit, but were not told their serum cholesterol value (n = 284). Individuals (n = 115) in two worksites served as a nonrandomized 'untreated control group'. Subjects were tested for serum cholesterol and completed a questionnaire at baseline, and 3 and 6 months later.

RESULTS

Dietary changes occurred in seven of nine categories in individuals subjects to the full and partial interventions but in only one of nine categories in those studied in the control condition. Mean dietary intake differed between the full and partial intervention conditions for only three of nine dietary categories. Cholesterol level dropped in the full, partial and control conditions by 4.9, 3.9 and 9.6%, respectively.

CONCLUSIONS

Dietary education has favorable effects on the dietary behaviors of individuals. Being told one's cholesterol level at the outset of this educational intervention has little effect on dietary change.

Predictors of sun exposure in adolescents in a southeastern U.S. population

PURPOSE

With the increase in melanoma incidence, the sun exposure and protective behaviors of adolescents are of great concern. Limited data are available on the prevalence and predictors of risk behavior in adolescents in the southeastern United States. This study examined the levels of sun exposure and variables predictive of sun exposure among adolescents in two Alabama middle schools.

METHODS

A total of 509 sixth-graders completed a self-administered survey assessing: (a) their knowledge, attitudes, and beliefs about malignant melanoma; and (b) their sun exposure and sunburns for a specific weekend and for the summer.

RESULTS

Levels of sun exposure and frequency of sunburn were high. Regression models determined the predictors of weekend and summer sun exposure, and weekend sunburn. Significant predictors varied by outcome and included gender, perceived importance of a suntan, parent and peer modeling, and sunscreen use.

CONCLUSION

Reducing the risk of melanoma will require a three-pronged intervention strategy with efforts directed at adolescents, their parents, and the broader community.

Beyond air quality--factors that affect prevalence estimates of sick building syndrome

If the prevalence of sick building syndrome (SBS) is estimated before intervention begins, then a reduction in the estimate may later be used to measure success of the intervention, and in particular, those efforts toward improving air quality. However, the measure of success will be distorted if factors other than air quality affect the SBS prevalence estimate. In this study the background prevalence of SBS was estimated and study factors identified that alone affected the estimate. Two symptom questionnaires were randomly administered to workers from 39 offices before routine physical examinations; one questionnaire described the SBS study, the other did not. SBS was defined as a symptom in the prior 24-hour or 7-day recall period that was more severe at work and not related to suspected confounders--allergy, cold, flu. Prevalence and prevalence ratios were estimated along with 95% confidence intervals (CI). Symptoms were reported by 45% of 1088 workers surveyed, but most reported them as more severe outside work or related them to confounders. SBS prevalence was 5%. It was 3.2 times higher (95% CI: 1.8, 5.7) among workers cognizant of the study relative to those blinded, 2.2 times higher (95% CI: 1.2, 4.1) for the 7-day relative to the 24-hour recall period, and 2.5 times higher (95% CI: 1.4, 5.0) for females. SBS prevalence did not differ by workday or age. Since study factors alone affected prevalence estimates, a standardized assessment method seems necessary for SBS.

Increasing screening mammography in asymptomatic women: evaluation of a second-generation, theory-based program

Two theory-based programs to increase mammography screening rates among asymptomatic women were implemented and evaluated in the community. One program (E) was based on the Health Belief Model (HBM); the second program (EP) added exercises adapted from the social psychology of compliance. Program impact on screening among 295 primarily Caucasian, middle-class women was evaluated against untreated controls (C) over a 6-month period. Both programs led to increases in HBM components (Perceived Susceptibility, and Perceived Benefits) and Intentions to obtain a mammogram. Screening rates 2 to 3 times higher were observed in the EP and E over C conditions; EP and E did not differ. A mediational model of compliance illustrated the interplay of HBM components in the compliance process.

Evaluation of a self-help program to reduce alcohol consumption among pregnant women

This study tested a cognitive-behavioral intervention for reducing alcohol consumption among economically disadvantaged pregnant women. The intervention included a 10-minute educational session and a nine-step self-help manual. Women attending public health maternity clinics completed a screening questionnaire, a pretest questionnaire, were randomly assigned to receive the self-help intervention or usual clinic care, and completed a posttest questionnaire. A higher alcohol quit rate was observed among the intervention participants (88%) than controls (69%). The effect was strongest for "light" drinkers, African-Americans, and non-Protestants. This approach may be useful in clinics where staff time is limited.

Increasing screening mammography in asymptomatic women: evaluation of a second-generation, theory-based program

Two theory-based programs to increase mammography screening rates among asymptomatic women were implemented and evaluated in the community. One program (E) was based on the Health Belief Model (HBM); the second program (EP) added exercises adapted from the social psychology of compliance. Program impact on screening among 295 primarily Caucasian, middle-class women was evaluated against untreated controls (C) over a 6-month period. Both programs led to increases in HBM components (Perceived Susceptibility, and Perceived Benefits) and Intentions to obtain a mammogram. Screening rates 2 to 3 times higher were observed in the EP and E over C conditions; EP and E did not differ. A mediational model of compliance illustrated the interplay of HBM components in the compliance process.

A study of breast cancer detection practices and beliefs in black women attending public health clinics

In this study, breast cancer knowledge, beliefs and practices in low income black women were examined. First, focus groups were held with a total of 33 participants. Information gathered from the focus groups was used to develop a telephone survey which was partially based on the Health Belief Model (HBM) and administered to 92 subjects. Utilization rates of mammography and breast self-examination (BSE) were quite high; 66.3% of survey participants reported having at least one mammogram and 72.5% performed BSE. Because low-cost mammograms were available to the survey participants, these results suggest that women in this target population will utilize accessible and affordable mammograms. Several knowledge deficiencies that need to be addressed were also identified. Most of the health beliefs were not significantly associated with mammography or BSE utilization. Because the HBM has never been extensively tested on this population, its appropriateness as a behavior model for low-income women is examined. Implications for future research and interventions are discussed.

The impact of public cholesterol screening on diet, general well-being, and physician referral

Public cholesterol screenings have become common. To evaluate the public health impact of such events, we conducted a public cholesterol screening and, three months later, invited participants between the ages of 18 and 72 to return for follow-up. More than 77% (N = 143) returned. We collected information on diet and general well-being at baseline and follow-up, and we obtained information on further medical evaluation of the initial cholesterol value at follow-up. Diet improved regardless of baseline cholesterol level (overall diet score 2.10 baseline, 1.75 follow-up, P less than .001). There were no adverse psychosocial ("labeling") effects in persons told of elevated cholesterol levels. About one-third of individuals referred to their physicians for elevated cholesterol values discussed the cholesterol issue with their physicians, as did a similar proportion of those told of a desirable cholesterol level. Total cholesterol decreased from 218.5 to 211.6 mg/dL (P = 0.18, 95% CI for the change, -18.5 to +4.7 mg/dL). Public cholesterol screening did not appear to have any adverse effects and may lead to beneficial changes in diet in persons screened.

Increasing the use of mammography: a pilot program

Despite the effectiveness of mammography, a large percentage of eligible women do not obtain screening mammograms. Two programs designed to increase the use of mammography were designed, implemented and evaluated. One hundred and fifty-six women were recruited and assigned to an Educational plus Psychological program (EP), an Educational program (E), or to a delayed treatment control group (C). Women completed a pretest, a posttest (EP and E only) and a telephone follow-up. At posttest, EP women had greater intention to obtain a mammogram than C women. EP and E women had higher levels of knowledge and higher levels of perceived benefit of mammography than C women. Actual compliance did not differ among the three conditions. Implications for the design of future programs are discussed.

Psychosocial predictors of physical activity in adolescents

Regular physical activity consistently demonstrates an inverse relationship with coronary heart disease and has positive effects on quality of life and other psychological variables. Despite the benefits of exercise, many youth and adults maintain a sedentary lifestyle. Interventions are needed, particularly with youth, to increase levels of physical activity. A better understanding of the psychosocial predictors of physical activity will aid in structuring these interventions. Longitudinal data from a cohort of 743 10th-grade students from the control condition of the Stanford Adolescent Heart Health Program were analyzed. Regression analysis indicated that psychosocial variables were significantly related to physical activity after controlling for baseline levels of physical activity and BMI. Associations with physical activity were found for intention to exercise, self-efficacy, stress, and direct social influence. The designers of future interventions should consider including program components that target these variables.