Kim D. Reynolds

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.

Acculturation, physical activity, and fast-food consumption among Asian-American and Hispanic adolescents.

Previous studies have implicated acculturation to the US as a risk factor for unhealthy behaviors among Hispanic and Asian-American adolescents, including substance use, violence, and unsafe sex. This study examined the association between acculturation and obesity-related behaviors•physical activity and fast-food consumption•among 619 Asian-American and 1385 Hispanic adolescents in Southern California. Respondents completed surveys in 6th and 7th grade. The 6th grade survey assessed acculturation with the AHIMSA acculturation scale and a measure of English language usage. The 7th grade survey assessed frequency of moderate-to-intense physical activity and frequency of eating fast-food. Multiple regression analyses included acculturation and demographic covariates as predictors of physical activity and fast-food consumption. Acculturation to the US, assessed in 6th grade, was significantly associated with a lower frequency of physical activity participation and a higher frequency of fast-food consumption in 7th grade. The significant associations persisted after controlling for covariates and were consistent across gender and ethnic groups. Results suggest that acculturation to the US is a risk factor for obesity-related behaviors among Asian-American and Hispanic adolescents. Health promotion programs are needed to encourage physical activity and healthy diets among adolescents in acculturating families.

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.

The Role of Availability as a Moderator of Family Fruit and Vegetable Consumption

The public health objective to improve the diet of Americans includes increasing the consumption of fruits and vegetables (F&V). The availability of F&V in the home has been suggested but not confirmed as one environmental factor that influences the types and quantities of F&V eaten by family members. Using a model of parental and child influences on a child’s intake of F&V, the authors investigated F&V availability as a moderating variable for the relationships between the model constructs and how the relationships might change with varying levels of F&V availability. Path analysis and multigroup structural equation modeling were the analytic tools. Results indicated that homes with more F&V available had a richer and generally stronger set of motivating factors for parent and child F&V consumption than homes with low F&V availability. Findings have implications for parental involvement in interventions to enhance the diet of fourth-grade children.

Childhood obesity and proximity to urban parks and recreational resources: A longitudinal cohort study

The objective of the research was to assess how proximity to parks and recreational resources affects the development of childhood obesity through a longitudinal study. Data were collected on 3173 children aged 9-10 from 12 communities in Southern California in 1993 and 1996. Children were followed for eight years to collect longitudinal information, including objectively measured body mass index (BMI). Multilevel growth curve models were used to assess associations between attained BMI growth at age 18 and numerous environmental variables, including park space and recreational program access. For park acres within a 500 m distance of childrens homes, there were significant inverse associations with attained BMI at age 18. Effect sizes were larger for boys than for girls. Recreation programs within a 10 km buffer of childrens homes were significantly and inversely associated with achieved levels in BMI at age 18, with effect sizes for boys also larger than those for girls. We conclude that children with better access to parks and recreational resources are less likely to experience significant increases in attained BMI.

Social Cognitive Model of Fruit and Vegetable Consumption in Elementary School Children

Fruit and vegetable consumption is related to reduced risk for certain forms of cancer. Health organizations recommend the increased consumption of fruit and vegetables. Despite these recommendations, few U.S. children eat the recommended number of at least five servings of fruit and vegetables per day. Understanding the determinants of consumption might improve our ability to increase consumption. Few theory-based models have been developed to explain and predict the consumption of various foods by children. This study proposed a model to explain fruit and vegetable consumption in children based on Social Cognitive Theory and on the literature in nutrition education. The model was tested using structural equation modeling techniques. Data from 414 third-graders were gathered on five predictors including availability, modeling, nutrition education, motivation (i.e., self-efficacy, outcome expectancies, food preferences), and knowledge. The proposed model was tested with two random splits of the data and also separately for males and females. Results indicate adequate fit of the models for each of the four data sets (split 1, split 2, males, females). The pattern of significant paths was similar across the data sets. Availability and motivation (i.e., self-efficacy, outcome expectancies, food preference) were most consistently related to consumption and to other constructs in the model.

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.

Linking empirically based theory and evaluation: the Family Bereavement Program.

ConclusionWe have illustrated how our “small theory” (Lipsey, 1990) of bereavement guided the development and evaluation of a preventive intervention for bereaved children. Our small theory, based on prior empirical research, enabled us to identify family processes that appeared to mediate the effects of parental death on child mental health. Our intervention was designed to attempt to change these processes. The evaluation of our experimental trial of the intervention assessed changes on these processes as well as the more distal mental health outcomes. The experimental trial showed some-what encouraging results, in terms of the programs ability to modify the warmth of the parent–child relationship and to decrease symptomatology in the adolescent children. We also obtained further empirical support for our underlying theoretical model. Finally, implications for redesign of the program were derived from assessing the adequacy of the program components to change each of the mediators in the theoretical model.

Children's fruit and vegetable intake: Socioeconomic, adult-child, regional, and urban-rural influences

Abstract National objectives for fruit and vegetable (F&V) consumption have been set at five or more servings per day. The National Cancer Institute funded three interventions aimed at increasing F&V consumption among elementary school children. Focus group discussions were held with fourth- and fifth-grade students, their parents, teachers, and food service workers in three regions to determine if environmental, personal, and behavioral influences differed across socioeconomic status (SES), regional, urban-rural, adult-child, and ethnic groups. Discussion guides for focus group sessions were based on the three domains of social cognitive theorys reciprocal determinism: environmental, behavioral, and personal characteristics. Discussions were conducted with groups of students (15), parents (11), teachers (6), and food service workers (6). A systematic content analysis was conducted with THE ETHNOGRAPH,® a software system. Differences in the three major components of reciprocal determinism were found across SES, urban-rural, regional, and adult-child factors. Middle to high SES groups reported a much larger variety of F&Vs available in their homes. Children from low and very low SES groups appeared to be responsible for preparing more meals alone. Children, not adults, thought of vegetables as “grown-up” foods.

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.