What's Behind the Dramatic Pre-2020 Declines in Hispanic/Latina Adolescent Childbearing? Decomposing Change by Age, Origin, and Nativity.

PURPOSE: To assess whether the large declines in adolescent childbearing among Hispanic adolescents over the period 2000-2019 have been driven by co-occurring changes in the composition of the Hispanic population and, if so, whether they have done so differentially by Hispanic subgroup. METHODS: We use birth counts from the United States vital statistics system and population denominators from the United States decennial census long form 5-percent Public Use Microdata and the American Community Survey to conduct a decomposition analysis apportioning observed declines in Hispanic adolescent childbearing to: (1) compositional shifts in nativity, age, and region-of-origin and (2) subgroup changes in childbearing rates. RESULTS: The Hispanic adolescent fertility rate fell by over 71% from 2000 to 2019, with Mexican-Origin, United States-born, and younger adolescents exhibiting the steepest declines (79%, 70%, and 80% declines, respectively). Results from the decomposition analysis show that almost 90% of the decline is due to within-group rate change, with some variability by subgroup and by decade. Only 10% of the decline was due to compositional changes, with shifts in nativity driving much of the effect. DISCUSSION: Declines in Hispanic adolescent childbearing over the last decades have occurred in spite of substantial shifts in the composition of the Hispanic population, not because of them. These findings set the stage for a more detailed examination of the drivers of change in sexual activity, contraceptive use, and abortion, all of which are proximate determinants of adolescent pregnancy and childbearing. Additionally, a focus on more distal factors is needed, including the role that changing political, societal, and economic conditions in the United States have for early fertility patterns.

Exploring the experiences of pregnant women in the U.S. during the first year of the Covid-19 pandemic.

In this paper, we integrate the stress process model with symbolic interactionism to frame our analysis of interviews with 35 women who were pregnant and/or gave birth during the first year of the Covid-19 pandemic. We detail three stressors, highlight their variation, and discuss how they coped with these stressors. Women reported having to navigate contradictory information about the public health crisis, but Black participants simultaneously endured added strain from a heightened awareness of racialized violence. To cope with an overabundance of precarious and contradictory messages, some women sought out information (i.e., information gatherers), others eschewed information (i.e., information avoiders), and most established protective "bubbles." Next, women experienced disruptions in pregnancy rituals but coped by reframing their expectations. This stressor, however, was less acute for women with a prior birth. Third, women shared feelings of social isolation and reduced social support, which were intensified if pregnancy complications occurred. Women coped by relying on telecommunication and at-home monitoring devices. Our study shows how pregnant women experienced and coped through adversity to mitigate stressors amid pandemonium.

Association of the Quality Rating and Improvement System, Texas Rising Star, on Physical Activity and Screen Time Policies and Practices in Texas Child Care Centers.

PURPOSE: Quality rating and improvement systems (QRIS) are systems approaches to assist states in providing high quality early childhood education. Texas Rising Star (TRS), a voluntary QRIS, exceeds state licensing standards and meets some obesity prevention guidelines. This study examines differences in physical activity, screen time, and outdoor policies and practices by QRIS certification. DESIGN: Cross-sectional. SETTING: Online. SAMPLE: After exclusion criteria, respondents were 431 Texas childcare centers. MEASURES: 2016 survey of policies and Go NAPSACC best practices. ANALYSIS: Chi-square and t-tests indicated differences in 1) practices and 2) policies by QRIS status. RESULTS: TRS-certified centers reported more policies for physical activity (M = 4.57 ± 3.07 vs. 3.61 ± 2.95, p = 0.009) and screen time (M = 1.91 ± 1.84 vs. 1.28 ± 1.56, p < 0.001) than non-certified centers. TRS-certified centers reported significantly higher frequencies for 7 of 14 physical activity practices, however no significant differences for screen time practices were found. Additionally, TRS-certified centers reported more outdoor practices, including more classrooms/storage (p < 0.001) and vegetable gardens (p = 0.025). CONCLUSION: TRS-certified centers reported more physical activity policies and practices, more screen time policies, and more outdoor practices. TRS certification was not associated with screen time practices. QRIS can be a practical way to insert obesity prevention in early care and education. Using items from a widely used survey enables comparisons, however future research is needed in larger-scale studies. Some COVID-19 implications are discussed.

Authorship Policies at U.S. Doctoral Universities: A Review and Recommendations for Future Policies.

Intellectual contribution in the form of authorship is a fundamental component of the academic career. While research has addressed questionable and harmful authorship practices, there has largely been no discussion of how U.S. academic institutions interpret and potentially mitigate such practices through the use of institution-level authorship policies. To gain a better understanding of the role of U.S. academic institutions in authorship practices, we conducted a systematic review of publicly available authorship policies for U.S. doctoral institutions (using the 266 2018 Carnegie-classified R1 and R2 Universities), focusing on components such as specification of authorship criteria, recommendations for discussing authorship, dispute resolution processes, and guidance for faculty-student collaborations. We found that only 24% of the 266 Carnegie R1 and R2 Universities had publicly available authorship policies. Within these policies, the majority (93%) specified criteria for authorship, but provided less guidance about actual processes for applying such criteria (62%), handling authorship disputes (62%), and managing faculty-student author teams (49%). Further, we found that any discussion of dispute resolution practices typically lacked specificity. Recommendations grounded in these findings are offered for institutions to leverage their ability to guide the authorship process by adopting an authorship policy that acknowledges disciplinary diversity while still offering substantive guidance.

Adiposity, cardiovascular, and health-related quality of life indicators and the reallocation of waking movement behaviors in preschool children with overweight and obesity: An isotemporal data analysis.

BACKGROUND: Isotemporal substitution evaluates hypothetical time replacement scenarios of physical movement on health, with few studies conducted among ethnically diverse preschool-aged populations. This study examines the reallocation of waking movement behaviors on adiposity, cardiovascular, and quality of life indicators among low-income, majority Hispanic preschool-aged youth (2-5 years) with overweight. METHODS: Participants wore an ActiGraph monitor (waist) and completed adiposity, cardiovascular, and health-related quality of life health assessments. Covariates included age, sex, ethnicity, and socioeconomic status. The isotemporal substitution approach was employed to address study aims. RESULTS: Complete data were available for 131 preschoolers. For boys, reallocating 5 minutes of stationary time with light intensity, moderate to vigorous intensity, or total physical activity showed a relation with beneficial reductions in adiposity indicators; for girls, these relations were statistically null. For boys and girls, reallocating 5 minutes of stationary time [-2.2 (95% CI: -3.7, -0.7) mmHg], light intensity [-2.1 (95% CI: -3.7, -0.7) mmHg], or moderate intensity activity [-2.7 (95% CI: -5.0, -0.4) mmHg] to vigorous intensity activity was related to favorable systolic blood pressure. Reallocating 5 minutes of stationary time to moderate to vigorous intensity activity [0.6 (95% CI: -1.0, -0.1) mmHg] or total physical activity [-0.2 (95% CI: -0.3, -0.01) mmHg] was related to lowered systolic blood pressure. Reallocating 5 minutes of stationary time to moderate to vigorous intensity activity [0.6 (95% CI: -1.1, -0.02) bpm] was related to lowered resting heart rate. No significant results for quality of life were found. CONCLUSION: Reallocation of time from stationary time to other movement behaviors is associated with several favorable adiposity and cardiovascular health outcomes among preschool children with overweight and obesity.

Examining physical activity policies to practice implementation: Results from the Texas Early Childhood Physical Activity Survey in non-Head Start childcare centers.

Ensuring young children have adequate opportunities for physical activity (PA) is important, and policies at childcare centers may help to ensure children have adequate opportunities. The purpose of this study is to examine the associations between center policies and odds of meeting best practices for PA in non-Head Start Texas early care and education (ECE) centers. Licensed centers with publicly available email addresses on the Texas Department of Family and Protective Services website were invited to participate in an online survey in February 2016. A total of 10 PA-related policies and 11 best practices were assessed. Logistic regression models assessed the odds of meeting best practices with each written policy (vs. no written policy). Covariates included center enrollment size. Exclusion criteria yielded a cross-sectional sample of 481 center respondents. Centers reported, on average, 3.92 (SD = 3.00) policies and meeting 4.55 (SD = 1.99) best practices. Each policy was associated with higher odds of meeting at least one best practice. Education policies and structured, adult-led active play policies were associated with meeting most PA best practices. No policies were associated with meeting best practices for seated time or for providing preschoolers recommendation daily minutes of indoor and outdoor PA. Texas ECEs report a low number of written policies and best practice implementation. The findings suggest policies alone may not be enough for implementation of best practices. There are opportunities for enhancement in mandated licensing, policy development, and best practice implementation surrounding PA.

Support for Breastfeeding Employees: Assessing Statewide Worksite Lactation Support Recognition Initiatives in the United States.

BACKGROUND: Although the reasons for discontinued breastfeeding are multifactorial, an unsupportive work environment is consistently reported as a barrier to continued breastfeeding. In the United States, several state breastfeeding advocates have taken a distinctive approach to promote worksite lactation support by developing statewide recognition initiatives aimed at incentivizing employers to support breastfeeding employees by offering public recognition for the worksites' efforts. RESEARCH AIM: To identify and describe statewide worksite lactation support recognition initiatives in the United States. METHODS: Between May 2016 and June 2017, semi-structured phone interviews were conducted with breastfeeding experts in each U.S. state (N = 60 participants) for this cross-sectional study. Experts in states with a recognition initiative were asked about the background, structure, and requirements of the initiative. RESULTS: Twenty-six states had a current initiative, and some had requirements for providing a private space (n = 19; 73%) and time (n = 18; 69%) for employees to express human milk, as well as a written worksite lactation support policy (n = 10; 38%). CONCLUSIONS: This was the first study in which researchers systematically identified ongoing worksite lactation support recognition initiatives in the United States. The results of this work also served to highlight both the similarities and the variety between initiatives. Future researchers should aim to determine the components of an initiative that increase employer support and, in turn, breastfeeding rates.

Physical activity, screen time, and outdoor learning environment practices and policy implementation: a cross sectional study of Texas child care centers.

BACKGROUND: Early care and education (ECE) centers are important for combating childhood obesity. Understanding policies and practices of ECE centers is necessary for promotion of healthy behaviors. The purpose of this study is to describe self-reported practices, outdoor environment aspects, and center policies for physical activity and screen time in a statewide convenience sample of non-Head Start Texas ECE centers. METHODS: Licensed home and child care centers in Texas with email addresses publicly available on the Department of Family and Protective Services website (N = 6568) were invited to participate in an online survey. Descriptive statistics of self-reported practices, policies, and outdoor learning environment are described. RESULTS: 827 surveys were collected (response rate = 12.6%). Exclusion criteria yielded a cross-sectional sample of 481 center-only respondents. > 80% of centers meet best practice recommendations for screen time practices for infants and toddlers, although written policies were low (M = 1.4 policies, SD = 1.65, range = 0-6). For physical activity, < 30% meet best practice recommendations with M = 3.9 policies (SD = 3.0, range = 0-10) policies reported. Outdoor learning environment indicators (M = 5.7 policies, SD = 2.5, range = 0-12) and adequate play settings, storage (< 40%), and greenery (< 20%) were reported. CONCLUSIONS: This statewide convenience sample of non-Head Start Texas ECE centers shows numerous opportunities for improvement in practices and policies surrounding outdoor environments, physical activity, and screen time. With less than half of centers meeting the recommendations for physical activity and outdoor learning environments, dedicating resources to help centers enact and modify written policies and to implement programs to improve their outdoor learning environments could promote physical activity and reduce sedentary time of children.

Contribution of Beverage Selection to the Dietary Quality of the Packed Lunches Eaten by Preschool-Aged Children.

BACKGROUND: Sweet drinks early in life could predispose to lifelong consumption, and the beverage industry does not clearly define fruit drinks as part of the sweet drink category. OBJECTIVES: To ascertain the relationship between beverage selection and dietary quality of the lunches packed for preschool-aged children evaluated using the Healthy Eating Index-2010. METHODS: Foods packed by parents (n=607) were observed at 30 early care and education centers on two nonconsecutive days. Three-level regression models were used to examine the dietary quality of lunches by beverage selection and the dietary quality of the lunch controlling for the nutrient composition of the beverage by removing it from the analysis. RESULTS: Fruit drinks were included in 25% of parent-packed lunches, followed by 100% fruit juice (14%), milk (14%), and flavored milk (3.7%). Lunches with plain milk had the highest Healthy Eating Index-2010 scores (59.3) followed by lunches with 100% fruit juice (56.9) and flavored milk (53.2). Lunches with fruit drinks had the lowest Healthy Eating Index-2010 scores at 48.6. After excluding the nutrient content of the beverage, the significant difference between lunches containing milk and flavored milk persisted (+5.5), whereas the difference between fruit drinks and 100% fruit juice did not. CONCLUSIONS: Dietary quality is associated with the type of beverage packed and these differences hold when the lunch is analyzed without the nutrient content of the beverage included.

Parent packs, child eats: Surprising results of Lunch is in the Bag's efficacy trial.

Early care and education (ECE) centers that require lunch brought from home provide an uncluttered view of parent-child dietary interactions in early childhood. Children's eating from parent-provided bag lunches was observed at 30 ECE centers in Texas, with 15 randomly assigned to the Lunch is in the Bag intervention to improve the lunch meal and 15 to a wait-list control condition. Study participants were parent and child aged 3-5 years (N = 633 dyads). Data were collected at baseline (pre-intervention) and follow-ups at weeks 6 (post-intervention), 22 (pre-booster), and 28 (post-booster). Changes effected in the children's lunch eating-e.g., increase of 14 percent in prevalence of children eating vegetables (SE = 5, P = 0.0063)-reciprocated changes in parent lunch-packing. Irrespective of intervention, however, the children consumed one-half to two-thirds of the amounts of whatever foods the parents packed, and the eat-to-pack ratio did not change across time. Thus, children's lunch eating at the ECE centers appeared to be regulated by perceptual cues of food availability rather than food preferences or internal cues of hunger and satiety.

Adequacy of Parent-Packed Lunches and Preschooler's Consumption Compared to Dietary Reference Intake Recommendations.

BACKGROUND: U.S. preschool children consume inadequate amounts of key nutrients. Understanding the contents of lunches packed by parents and consumed by their children can help identify areas of opportunity for the development of healthy food preferences. OBJECTIVE: To evaluate the nutrient adequacy of lunches packed by parents and consumed by children attending early care and education (ECE) centers. METHODS: Baseline data from 607 parent-child dyads in the "Lunch Is in the Bag" cluster-randomized controlled trial in Central Texas were examined. Foods packed by parents and consumed by children in sack lunches were observed at 30 ECE centers on 2 nonconsecutive days. Mean levels of energy, macronutrients, vitamins, and minerals were estimated with covariate-adjusted multilevel regression models that accounted for center-level clustering and repeated within-child measures. RESULTS: Energy (kilocalories) was 602.48 for packed lunches compared to 374.40 for consumed lunches. In packed lunches, percentage of energy as macronutrients for protein (14.8%), carbohydrate (55.9%), and total fat (31.2%) were within the acceptable macronutrient distribution range (AMDR) for the children's ages. Sugar (28.9% of energy) was above the AMDR recommendation. Only a quarter of parents packed 33% or more of the child's dietary reference intake (DRI) for dietary fiber. Over half the parents packed 33% or more of the DRI for vitamin A and calcium, and less than one in 8 packed 33% of the DRI for potassium. Children consistently consumed between 60 and 80% of the nutrients that were packed. CONCLUSIONS: Preschool children rely on parents to present them with healthy food choices, but lunches packed by parents for their preschool children do not consistently provide adequate nutrients. These data and the relationships between the dietary quality of packed and consumed lunches can be useful information to guide nutrition behavior change through targeted interventions.

Structuring Process Evaluation to Forecast Use and Sustainability of an Intervention: Theory and Data From the Efficacy Trial for Lunch Is in the Bag.

BACKGROUND: A cluster-randomized trial at 30 early care and education centers (Intervention = 15, waitlist Control = 15) showed the Lunch Is in the Bag intervention increased parents' packing of fruits, vegetables, and whole grains in their preschool children's bag lunches (parent-child dyads = 351 Intervention, 282 Control). PURPOSE: To examine the utility of structuring the trial's process evaluation to forecast use, sustainability, and readiness of the intervention for wider dissemination and implementation. METHOD: Pretrial, the research team simulated user experience to forecast use of the intervention. Multiattribute evaluation of user experience measured during the trial assessed use and sustainability of the intervention. Thematic analysis of posttrial interviews with users evaluated sustained use and readiness for wider dissemination. RESULTS: Moderate use was forecast by the research team. Multiattribute evaluation of activity logs, surveys, and observations during the trial indicated use consistent with the forecast except that prevalence of parents reading the newsletters was greater (83% vs. 50%) and hearing their children talk about the classroom was less (4% vs. 50%) than forecast. Early care and education center-level likelihood of sustained use was projected to be near zero. Posttrial interviews indicated use was sustained at zero centers. DISCUSSION: Structuring the efficacy trial's process evaluation as a progression of assessments of user experience produced generally accurate forecasts of use and sustainability of the intervention at the trial sites. CONCLUSION: This approach can assist interpretation of trial outcomes, aid decisions about dissemination of the intervention, and contribute to translational science for improving health.

Efficacy of the Lunch is in the Bag intervention to increase parents' packing of healthy bag lunches for young children: a cluster-randomized trial in early care and education centers.

BACKGROUND: Lunches that parents pack for their young children to eat at school or the Early Care and Education (ECE) center fall short of recommended standards. Lunch is in the Bag is a multi-level behavioral nutrition intervention to increase parents' packing of fruit, vegetables, and whole grains in their children's lunches. Designed for implementation in ECE centers, the five-week long intervention is followed three months later with a one-week booster. METHODS: Efficacy of Lunch is in the Bag was tested in cluster randomized trial. Participants were 633 families from 30 ECE centers (15 intervention, 15 control) across Austin, San Antonio, and Houston, Texas, USA. Primary outcomes were servings of fruit, vegetables, and whole grains observed in the children's parent-packed bag lunches. Servings of refined grains, meats/beans/eggs/nuts, dairy, chips, and sweets also were observed. Data were collected at baseline, post-intervention (6-week follow-up), pre-booster (22-weeks follow-up), and post-booster (28-week follow-up). Time-by-treatment interactions were analyzed separately for each of the food groups using multi-level models to compare changes from baseline. Analyses were adjusted for relevant demographic variables and clustering within centers and parents. RESULTS: The intervention effected increases from baseline to 6-week follow-up in vegetables (0.17 servings, SE = 0.04, P < 0.001) and whole grains (0.30 servings, SE = 0.13, P = 0.018). The increase in whole grains was maintained through the 28-week follow-up (0.34 servings, SE = 0.13, P = 0.009). Fruit averaged more than 1.40 servings with no differences between groups or across time. The intervention prevented increase in sweets (-0.43 servings, SE = 0.11, P < .001, at the 22-week follow-up). Parents persisted, however, in packing small amounts of vegetables (averages of 0.41 to 0.52 servings) and large amounts of sweets and chips (averages of 1.75 to 1.99 servings). CONCLUSIONS: The need for and positive effects of the Lunch is in the Bag intervention at ECE centers where parents send bag lunch for their preschool-aged children was confirmed. An important direction for future research is discovery of more options for leveraging the partnership of ECE centers and families to help young children learn to eat and enjoy vegetables and other healthy foods in preference to less healthy choices such as chips and sweets. TRIAL REGISTRATION: The Clinical Trials Number is NCT01292434 .

Dietary Quality of Preschoolers' Sack Lunches as Measured by the Healthy Eating Index.

BACKGROUND: Eating habits are developed during the preschool years and track into adulthood, but few studies have quantified dietary quality of meals packed by parents for preschool children enrolled in early care and education centers. OBJECTIVE: Our aim was to evaluate the dietary quality of preschoolers' sack lunches using the Healthy Eating Index (HEI) 2010 to provide parents of preschool children with guidance to increase the healthfulness of their child's lunch. DESIGN: This study is a cross-sectional analysis of baseline dietary data from the Lunch Is in the Bag trial. PARTICIPANTS: A total of 607 parent-child dyads from 30 early care and education centers in Central and South Texas were included. MAIN OUTCOME MEASURES: Total and component scores of the HEI were computed using data obtained from direct observations of packed lunches and of children's consumption. STATISTICAL ANALYSIS: Three-level regression models with random intercepts at the early care and education center and child level were used; all models were adjusted for child sex, age, and body mass index (calculated as kg/m(2)). RESULTS: Mean HEI-2010 total scores were 58 for lunches packed and 52 for lunches consumed, out of 100 possible points. Mean HEI component scores for packed and consumed lunches were lowest for greens and beans (6% and 8% of possible points), total vegetables (33% and 28%), seafood and plant proteins (33% and 29%), and whole grains (38% and 34%); and highest for empty calories (85% and 68% of possible points), total fruit (80% and 70%), whole fruit (79% and 64%), and total protein foods (76% and 69%). CONCLUSIONS: Parents of preschool children pack lunches with low dietary quality that lack vegetables, plant proteins, and whole grains, as measured by the HEI. Education of parents and care providers in early care and education centers is vital to ensure that preschoolers receive high dietary-quality meals that promote their preference for and knowledge of a healthy diet.

Development of a Method to Observe Preschoolers' Packed Lunches in Early Care and Education Centers.

BACKGROUND: As early childhood education (ECE) centers become a more common setting for nutrition interventions, a variety of data collection methods are required, based on the center foodservice. ECE centers that require parents to send in meals and/or snacks from home present a unique challenge for accurate nutrition estimation and data collection. We present an observational methodology for recording the contents and temperature of preschool-aged children's lunchboxes and data to support a 2-day vs a 3-day collection period. METHODS: Lunchbox observers were trained in visual estimation of foods based on Child and Adult Care Food Program and MyPlate servings and household recommended measures. Trainees weighed and measured foods commonly found in preschool-aged children's lunchboxes and practiced recording accurate descriptions and food temperatures. Training included test assessments of whole-grain bread products, mixed dishes such as macaroni and cheese, and a variety of sandwich preparations. Validity of the estimation method was tested by comparing estimated to actual amounts for several distinct food types. Reliability was assessed by computing the intraclass correlation coefficient for each observer as well as an interrater reliability coefficient across observers. To compare 2- and 3-day observations, 2 of the 3 days of observations were randomly selected for each child and analyzed as a separate dataset. Linear model estimated mean and standard error of whole grains, fruits and vegetables, and amounts of energy, carbohydrates, protein, total fat, saturated fat, dietary fiber, thiamin, riboflavin, niacin, vitamins A and C, calcium, iron, sodium, and dietary fiber per lunch were compared across the 2- and 3-day observation datasets. RESULTS: The mean estimated amounts across 11 observers were statistically indistinguishable from the measured portion size for each of the 41 test foods, implying that the visual estimation measurement method was valid: intraobserver intraclass correlation coefficients ranged from 0.951 (95% CI 0.91 to 0.97) to 1.0. Across observers, the interrater reliability correlation coefficient was estimated at 0.979 (95% CI 0.957 to 0.993). Comparison of servings of fruits, vegetables, and whole grains showed no significant differences for serving size or mean energy and nutrient content between 2- and 3-day lunch observations. CONCLUSIONS: The methodology is a valid and reliable option for use in research and practice that requires observing and assessing the contents and portion sizes of food items in preschool-aged children's lunchboxes in an ECE setting. The use of visual observation and estimation with Child and Adult Care Food Program and MyPlate serving sizes and household measures over 2 random days of data collection enables food handling to be minimized while obtaining an accurate record of the variety and quantities of foods that young children are exposed to at lunch time.

Promoting energy-balance behaviors among ethnically diverse adolescents: overview and baseline findings of The Central Texas CATCH Middle School Project.

The Central Texas Coordinated Approach To Child Health (CATCH) Middle School Project is a 3.5-year school-based project aimed at promoting physical activity (PA), healthy eating, and obesity prevention among public middle school students in Texas. This article describes the CATCH intervention model and presents baseline findings from spring 2009. CATCH comprises six core components: CATCH Team, CATCH PE, CATCH Classroom, CATCH Eat Smart Cafeteria, CATCH Family, and CATCH Social Marketing. A group randomized serial cross-sectional design is being employed to test the effect of three program support conditions (n = 10 schools each) on energy-balance behaviors: Basic (training and curriculum only), Basic Plus (training and curriculum plus CATCH facilitator support), and Basic Plus Social Marketing (all inputs plus social marketing component). The study sample is composed of a cross-sectional sample of eighth-grade students (primary outcome evaluation sample) and sixth- and seventh-grade students (PE process evaluation sample) who are selected and measured each year. At baseline, 37.9% of eight-grade students (n = 2,841; 13.9 years) were overweight/obese and 19.2% were obese. Eighth-grade students reported, on average, consuming sugar-sweetened beverages more than two times on the previous day and fruits and vegetables roughly three times on the previous day; only two of five school districts surpassed the recommended 50% cut-point for class time spent in moderate-and-vigorous PA as measured in classes of sixth- and seventh-grade students. Additional behavioral findings are reported. Body mass index and behaviors were comparable across conditions. Baseline findings underscore the need to promote student energy-balance behaviors.

Objective habitual physical activity and estradiol levels in obese Latina adolescents.

BACKGROUND: Lifetime physical activity (PA) is associated with decreased breast cancer (BC) risk; reports suggest that PA during adolescence contributes strongly to this relationship. PA lowers production of sex hormones, specifically estradiol, or decreases insulin resistance (IR), thereby lowering risk. Overweight Latina adolescents are insulin resistant and exhibit low levels of PA, potentially increasing their future BC risk. METHODS: 37 obese Latina adolescents (15.7 ± 1.1 yrs) provided measures of PA using accelerometry; plasma follicular phase estradiol, sex-hormone binding globulin, total and free testosterone, dehydroepiandrosterone-sulfate (DHEAS); IR using HOMA-IR; and body composition via DEXA. Partial correlations and stepwise linear regressions assessed cross-sectional relationships between sex hormones, IR and PA. Body composition, and age were included a priori as covariates. RESULTS: Estradiol was negatively associated with accelerometer counts per minute (CPM; r = -0.4; P = .02), percent time spent in moderate PA (%MPA; r = -0.5; P = .006), and percent time in moderate or vigorous PA (%MVPA; r = -0.5; P = .007). DHEAS was positively associated with CPM (r = .4, P = .009), %MPA (r = .3, P = .04), and %MVPA (r = .3, P = .04). Other sex hormones and IR were not associated with PA measures. CONCLUSION: This study is the first to show that higher habitual PA was inversely associated with estradiol in obese adolescents.

Randomized controlled trial to improve adiposity, inflammation, and insulin resistance in obese African-American and Latino youth.

The purpose of this study was to examine ethnic differences in the metabolic responses to a 16-week intervention designed to improve insulin sensitivity (SI), adiposity, and inflammation in obese African-American and Latino adolescents. A total of 100 participants (African Americans: n = 48, Latino: n = 52; age: 15.4 ± 1.1 years, BMI percentile: 97.3 ± 3.3) were randomly assigned to interventions: control (C; n = 30), nutrition (N; n = 39, 1×/week focused on decreasing sugar and increasing fiber intake), or nutrition + strength training (N+ST; n = 31, 2×/week). The following were measured at pre- and postintervention: strength, dietary intake, body composition (dual-energy X-ray absorptiometry/magnetic resonance imaging) and glucose/insulin indexes (oral glucose tolerance test (OGTT)/intravenous glucose tolerance test (IVGTT)) and inflammatory markers. Overall, N compared to C and N+ST reported significant improvements in SI (+16.5% vs. -32.3% vs. -6.9% respectively, P < 0.01) and disposition index (DI: +15.5% vs. -14.2% vs. -13.7% respectively, P < 0.01). N+ST compared to C and N reported significant reductions in hepatic fat fraction (HFF: -27.3% vs. -4.3% vs. 0% respectively, P < 0.01). Compared to N, N+ST reported reductions in plasminogen activator inhibitor-1 (PAI-1) (-38.3% vs. +1.0%, P < 0.01) and resistin (-18.7% vs. +11.3%, P = 0.02). There were no intervention effects for all other measures of adiposity or inflammation. Significant intervention by ethnicity interactions were found for African Americans in the N group who reported increases in total fat mass, 2-h glucose and glucose incremental areas under the curve (IAUC) compared to Latinos (P's < 0.05). These interventions yielded differential effects with N reporting favorable improvements in SI and DI and N+ST reporting marked reductions in HFF and inflammation. Both ethnic groups had significant improvements in metabolic health; however some improvements were not seen in African Americans.

Increasing Physical Activity Decreases Hepatic Fat and Metabolic Risk Factors.

This study assessed the changes in time spent in moderate to vigorous physical activity (MVPA) on fat depots, insulin action, and inflammation. Longitudinal data were generated from 66 Hispanic adolescents (15.6±1.1 yr; BMI percentile 97.1±3.0) who participated in a 16-wk nutrition or nutrition+exercise intervention. There were no effects of the intervention on PA, but there were inter-individual changes in PA. For purposes of this analysis, all intervention groups were combined to assess how changes in PA during 16 wk affected changes in adiposity, insulin action, and markers of inflammation. MVPA was assessed by 7-day accelerometry, total body fat via DXA, liver fat by MRI, and insulin, glucose and HOMA-IR via a fasting blood draw. A repeated measures ANCOVA was used to assess the effect of MVPA on fat depots, insulin action, and inflammatory markers. Sixty-two percent of participants increased MVPA (mean increase, 19.7±16.5 min/day) and 38% decreased MVPA (mean decrease, 10.7±10.1 min/day). Those who increased MVPA by as little as 20 min per day over 16 wk, compared to those who decreased MVPA, had significant reductions in liver fat (-13% vs. +3%; P=0.01), leptin levels (-18% vs. +4%; P=0.02), and fasting insulin (-23% vs. +5%; P=0.05). These findings indicate that a modest increase in MVPA can improve metabolic health in sedentary overweight Hispanic adolescents.