Hannah G. Lawman

The integration of a family systems approach for understanding youth obesity, physical activity, and dietary programs.

Rates of overweight in youth have reached epidemic proportions and are associated with adverse health outcomes. Family-based programs have been widely used to treat overweight in youth. However, few programs incorporate a theoretical framework for studying a family systems approach in relation to youth health behavior change. Therefore, this review provides a family systems theory framework for evaluating family-level variables in weight loss, physical activity, and dietary approaches in youth. Studies were reviewed and effect sizes were calculated for interventions that manipulated the family system, including components that targeted parenting styles, parenting skills, or family functioning, or which had novel approaches for including the family. Twenty-one weight loss interventions were identified, and 25 interventions related to physical activity and/or diet were identified. Overall, family-based treatment programs that incorporated training for authoritative parenting styles, parenting skills, or child management, and family functioning had positive effects on youth weight loss. Programs to improve physical activity and dietary behaviors that targeted the family system also demonstrated improvements in youth health behaviors; however, direct effects of parent-targeted programming is not clear. Both treatment and prevention programs would benefit from evaluating family functioning and parenting styles as possible mediators of intervention outcomes. Recommendations are provided to guide the development of future family-based obesity prevention and treatment programs for youth.

A Review of Family and Environmental Correlates of Health Behaviors in High-Risk Youth

Disparities in the prevalence of obesity in youth place minority and low socioeconomic status youth at increased risk for the development of chronic disease, such as metabolic syndrome and type 2 diabetes. Contributing factors to the increases in obesity include a decline in positive health behaviors, such as making healthy dietary choices, engaging in physical activity, and limiting sedentary behaviors. Family and physical environmental contextual factors related to health behaviors are increasingly the focus of health behavior interventions in line with the bioecological model that encourages a system‐focused perspective on understanding health behavior influences. Physical environmental characteristics, such as home and neighborhood characteristics and resources, provide the tangible means to support health behaviors and are important contextual variables to consider that may increase intervention effectiveness. Therefore, the current review seeks to highlight the importance of investigating influences of behavior beyond individual characteristics in understanding factors related to the risk of developing metabolic syndrome and type 2 diabetes in youth at high risk for developing chronic disease. The current study reviews the non‐intervention literature on family and physical environmental factors related to health behaviors (i.e., diet, physical activity, and sedentary behavior) in youth who are considered to be at‐risk for developing metabolic syndrome and type 2 diabetes. Results on 38 published articles of diet, physical activity, and sedentary behaviors showed support for the role of parenting and physical environmental factors, particularly parental monitoring and neighborhood context, such as social cohesion, as they relate to health behaviors in high‐risk youth. Implications and recommendations for future research are discussed.

An overview of the Positive Action for Today's Health (PATH) trial for increasing walking in low income, ethnic minority communities

BACKGROUND Ethnic minorities and lower-income adults have among the highest rates of obesity and lowest levels of regular physical activity (PA). The Positive Action for Todays Health (PATH) trial compares three communities that are randomly assigned to different levels of an environmental intervention to improve safety and access for walking in low income communities. DESIGN AND SETTING Three communities matched on census tract information (crime, PA, ethnic minorities, and income) were randomized to receive either: an intervention that combines a police-patrolled-walking program with social marketing strategies to promote PA, a police-patrolled-walking only intervention, or no-walking intervention (general health education only). Measures include PA (7-day accelerometer estimates), body composition, blood pressure, psychosocial measures, and perceptions of safety and access for PA at baseline, 6, 12, 18, and 24 months. INTERVENTION The police-patrolled walking plus social marketing intervention targets increasing safety (training community leaders as walking captains, hiring off-duty police officers to patrol the walking trail, and containing stray dogs), increasing access for PA (marking a walking route), and utilizes a social marketing campaign that targets psychosocial and environmental mediators for increasing PA. MAIN HYPOTHESES/OUTCOMES: It is hypothesized that the police-patrolled walking plus social marketing intervention will result in greater increases in moderate-to-vigorous PA as compared to the police-patrolled-walking only or the general health intervention after 12 months and that this effect will be maintained at 18 and 24 months. CONCLUSIONS Implications of this community-based trial are discussed.

Weight Status as a Moderator of the Relationship Between Motivation, Emotional Social Support, and Physical Activity in Underserved Adolescents

OBJECTIVE This study examined weight status as a moderator of the relationship between motivation (controlled, autonomous, regulatory), emotional social support (parents, peers) and moderate-to-vigorous physical activity (MVPA) in underserved adolescents (ethnic minority, low-income). METHODS Participants from the Active by Choice Today Trial (n = 1,416; 54% girls, 73% African American, 52% overweight/obese) completed baseline measures, including height and weight, psychosocial surveys, and 7-day accelerometry estimates. Weight status was defined by body mass index z-score (zBMI). RESULTS Weight status moderated the effects of controlled, autonomous, and regulatory motivation on MVPA, such that these variables were more strongly associated with MVPA in adolescents with lower versus higher zBMI scores. CONCLUSIONS A better understanding of why motivation is not related to MVPA in underserved youth with a higher weight status is needed. Future pediatric obesity treatment in underserved youth may need to move beyond motivation into environmental factors associated with long-term behavior change.

Accelerometry cut points for physical activity in underserved African Americans

BackgroundDespite their increased use, no studies have examined the validity of Actical accelerometry cut points for moderate physical activity (PA) in underserved (low-income, high-crime), minority populations. The high rates of chronic disease and physical inactivity in these populations likely impact the measurement of PA. There is growing concern that traditionally defined cut points may be too high for older or inactive adults. The present study aimed to determine the self-selected pace associated with instructions to “walk for exercise” and the corresponding accelerometry estimates (e.g., Actical counts/minute) for underserved, African American adults.MethodFifty one participants (61% women) had a mean age of 60.1 (SD = 9.9) and a mean body mass index of 30.5 kg/m2 (SD = 6.0). They performed one seated task, one standing task, and three walking tasks: “strolling”; “walking for exercise”; and “walking in an emergency.”ResultsThe average pace for strolling, walking for exercise, and walking in an emergency were 1.62 miles per hour (mph; SD = .51), 2.51 mph (SD = .53), and 2.86 mph (SD = .58), respectively. The average Actical counts/minute for the five activities were: 4 (SD = 15), 16 (SD = 29), 751 (SD = 591), 2006 (SD = 1095), and 2617 (SD = 1169), respectively. Regression analyses showed that the predicted counts/minute for a pace of 2.0 mph (which is used as the criterion for moderate exercise in this study) was 1075 counts/minute (SEM = 73).ConclusionsThe cut point associated with subjectively determined moderate PA is similar to those previously published for older adults and extends the use of adjusted cut points to African American populations. These results indicate that accurate cut points can be obtained using this innovative methodology.

Imputational modeling of spatial context and social environmental predictors of walking in an underserved community: the PATH trial.

BACKGROUND This study examined imputational modeling effects of spatial proximity and social factors of walking in African American adults. PURPOSE Models were compared that examined relationships between household proximity to a walking trail and social factors in determining walking status. METHODS Participants (N=133; 66% female; mean age=55 years) were recruited to a police-supported walking and social marketing intervention. Bayesian modeling was used to identify predictors of walking at 12 months. RESULTS Sensitivity analysis using different imputation approaches, and spatial contextual effects, were compared. All the imputation methods showed social life and income were significant predictors of walking, however, the complete data approach was the best model indicating Age (1.04, 95% OR: 1.00, 1.08), Social Life (0.83, 95% OR: 0.69, 0.98) and Income <

Reliability of 24-Hour Dietary Recalls as a Measure of Diet in African-American Youth

10,000 (0.10, 95% OR: 0.01, 0.97) were all predictors of walking. CONCLUSIONS The complete data approach was the best model of predictors of walking in African Americans.

Tracking and variability in childhood levels of BMI: The Bogalusa Heart Study

BACKGROUND Although it is a common practice to estimate dietary intake using three random 24-hour dietary recalls, some studies have suggested up to nine may be necessary to reliably estimate usual intake in youth. Given the resulting increase in resources and participant burden, more research is needed to determine whether this method is reliable, particularly in African-American youth at increased risk for obesity and other chronic diseases. OBJECTIVE This study estimated the reliability with which 24-hour dietary recalls measure energy, fat, fruit, and vegetable intake in African-American youth and examined how reliability changes as a function of the number of recalls. DESIGN This study used cross-sectional data collection across three studies. PARTICIPANTS/SETTING Participants were African-American youth (n=456, mean±standard deviation age 13.28±1.86 years, 64% were girls, mean±standard deviation body mass index [calculated as kg/m(2)] 31.45±7.94) who completed random 24-hour dietary recalls (67% completed three) conducted by research assistants using the Automated Self-Administered 24-Hour recall system (n=258) or registered dietitian nutritionists using the Nutrition Data System for Research (n=198). MAIN OUTCOME MEASURES/STATISTICAL ANALYSES Estimates provided by multilevel models were used to calculate the proportion of variance accounted for between individuals and the reliability of means within individuals as a function of the number of recalls. RESULTS Reliability estimates for assessing dietary outcomes using one to three recalls ranged from 11% to 62%. To achieve 80% reliability, the following number of recalls would need to be conducted: 8 for energy intake, 13 for fat intake, 21 to 32 for fruit intake, and 21 to 25 for vegetable intake. CONCLUSIONS The common practice of assessing dietary intake with three recalls does so with low reliability in African-American youth. Until more objective methods for reliably estimating usual intake are developed, researchers who choose to use 24-hour dietary recalls are encouraged to include estimates of the measures reliability in a priori power calculations for improved decision making regarding the number of observations and/or sample size.

Results of the “Active by Choice Today” (ACT) Randomized Trial for Increasing Physical Activity in Low-Income and Minority Adolescents

Although the tracking of BMI levels from childhood to adulthood has been examined, there is little information on the within‐person variability of BMI.