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.

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.

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.

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.

Dietary Intake, Attitudes toward Healthy Food, and Dental Pain in Low-Income Youth

Few studies have examined the relation between food consumption and related attitudes and dental pain among children. The objective of this study is to examine the associations of healthy and unhealthy food items, attitudes toward healthy food, and self-efficacy of eating healthy with dental pain among children. A cross-sectional analysis was performed using child survey data from the Texas Childhood Obesity Research Demonstration (TX CORD) project. Fifth-grade students ( n = 1,020) attending 33 elementary schools in Austin and Houston, Texas, completed the TX CORD Child Survey, a reliable and valid survey instrument focused on nutrition and physical activity behaviors. All nutrition questions ask about the number of times food and beverage items were consumed on the previous day. Dental pain was reported as mouth or tooth pain in the past 2 wk that made their mouth hurt so much that they could not sleep at night. Mixed-effects logistic regression models were used to test the association between 10 unhealthy food items, 9 healthy food items, 2 health attitudes, and self-efficacy with dental pain. All models controlled for sociodemographic variables. In total, 99 (9.7%) students reported dental pain. Dental pain was associated with intake of the following unhealthy items: soda, fruit juice, diet soda, frozen desserts, sweet rolls, candy, white rice/pasta, starchy vegetables, French fries/chips, and cereal (adjusted odds ratio [AOR], 1.27-1.81, P < 0.01). The intake of other vegetables (AOR, 1.56; P < 0.01), a healthy item, and the attitude that healthy food tastes good (AOR, 1.59; P = 0.04) were also positively associated with dental pain. The attitude of eating healthier leads to fewer health problems (AOR, 0.50) and self-efficacy for healthy eating (AOR, 0.44) were negatively associated with dental pain ( P < 0.01). Interventions should focus on improving oral health by reducing intake of unhealthy foods and educating children and families on the importance of diet as a means of reducing dental caries. Knowledge Transfer Statement: The results of this study can be used to inform researchers on potential food items and psychosocial measures to examine in low-income, minority populations for longitudinal research. These results would also be useful to educators who could incorporate oral health care and nutrition education into school curriculums.

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.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6588-5) contains supplementary material, which is available to authorized users.

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.

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.

How local and state regulations affect the child care food environment: A qualitative study of child care center directors' perspectives

Almost one-third of preschoolers spend regular time in child care centers where they can consume the majority of their daily dietary intake. The child care setting influences children's dietary intake. Thus, it is important to examine factors, such as local and state regulations, that influence the food environment at the center. This qualitative study explored directors' perceptions of how regulations influence the foods available at child care centers. Ten directors of centers in Travis County, Texas completed semi-structured interviews. Directors reported that changes in local health department regulations (e.g., kitchen specifications) result in less-healthful foods being served (e.g., more prepackaged foods). Directors of centers that do not participate in the federal Child and Adult Care Food Program (CACFP) said the state licensing regulations clarify the portion size and nutritional requirements for preschoolers thereby improving the nutritional quality of the food served. Directors of centers participating in CACFP said they are not affected by state mandates, because the CACFP regulations are more stringent. These findings suggest that state regulations that specify and quantify nutritional standards may beneficially impact preschoolers' diets. However, local health department regulations enacted to improve food safety may negatively influence the nutritional value of food served in centers.

Leptin predicts a decline in moderate to vigorous physical activity in minority female children at risk for obesity

What is already known about this subject Physical activity declines as children enter puberty. Leptin is cross-sectionally associated with physical activity, but there are conflicting findings on the magnitude and direction of this association. Leptin concentrations fluctuate during puberty, and may impact energy balance. What this study adds Leptin predicts the decline in physical activity during the start of puberty independent of central adiposity. Based on a median split of leptin, girls with low leptin levels have higher levels of physical activity than girls with high leptin levels at the start of puberty. Leptin levels at the start of puberty may provide a biological basis for the age-related physical activity decline in girls.

BACKGROUND

Leptin may influence moderate to vigorous physical activity (MVPA) at the start of puberty. The direction and magnitude of this association are unclear.

OBJECTIVES

To determine the effect of baseline leptin on MVPA over 1 year in minority girls at high risk for obesity.

METHODS

Data came from TRANSITIONS, a longitudinal observational study on the age-related MVPA decline. Fifty peripubertal girls aged 8-11 years at baseline participated. Baseline leptin (ng mL(-1) ) was collected via a duplicated assay using a double antibody radio immune assay. MVPA (min d(-1) ) was measured using accelerometers for at least four 10-h days on a quarterly basis for up to 1 year.

RESULTS

Continuous leptin was negatively related to MVPA (P = 0.001) independent of central adiposity at baseline and predicted the MVPA decline over 1 year (P = 0.002). For descriptive purposes, baseline leptin was dichotomized at the sample median into 'high leptin' and 'low leptin' categories to determine whether MVPA trajectories differed between these groups. Girls with 'low leptin' at baseline had significantly higher levels of MPVA at baseline, visit 1 and visit 2 compared to girls with 'high leptin'.

CONCLUSIONS

High leptin levels predicted nearly a 12.6% decline in MVPA over 1 year. These findings provide support for the biological basis of declining MVPA as girls enter puberty.

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.

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.

Physical activity, sedentary behavior, and the metabolic syndrome in minority youth

PURPOSE

This study aimed to determine the associations among physical activity, sedentary behavior, and the metabolic syndrome (MetS) in Latino and African American youth using both subjective and objective measures of activity levels.

METHODS

Cross-sectional data from 105 participants from three pediatric obesity studies that share a core set of methods and measures (Latino 74%, female 75%, mean age = 13 ± 3 yr) were used. Measures included moderate-to-vigorous physical activity and sedentary behavior by accelerometry and 3-Day Physical Activity Recall (3DPAR), fat and lean tissue mass by BodPod™, fasting glucose, lipids, blood pressure, and waist circumference. Associations between physical activity, sedentary behavior, and MetS were examined using ANCOVA, Pearson correlations, partial correlations, and logistic regressions with adjustments for age, sex, ethnicity, fat and lean mass, and pubertal Tanner stage.

RESULTS

Accelerometry data showed that greater time engaging in moderate-to-vigorous physical activity was related to lower odds of the MetS (odds ratio = 0.49, 95% confidence interval = 0.25-0.98), independent of sedentary behavior and covariates, and inversely correlated with fasting glucose (r = -0.21, P = 0.03) and systolic blood pressure (r = -0.25, P = 0.01), adjusting for covariates. Data from the 3DPAR showed that higher levels of sedentary behavior were related to higher odds of the MetS (odds ratio = 4.44, 95% confidence interval = 1.33-14.79), independent of moderate-to-vigorous physical activity and covariates, negatively correlated with HDL-cholesterol (r = -0.21, P = 0.04) and positively correlated systolic blood pressure (r = 0.26, P = 0.009), adjusting for covariates.

CONCLUSIONS

Future interventions aiming to improve metabolic health in youth should target both the promotion of physical activity and the reduction of sedentary behavior. Subjective and objective measures should be used in conjunction to better capture activity behaviors.

Relationships between IGF-1 and IGFBP-1 and adiposity in obese African-American and Latino adolescents

The purpose of this study was to examine interrelationships between insulin-like growth factor 1 (IGF-1), IGF binding proteins (IGFBPs), and adiposity in 49 African-American and 77 Latino obese adolescents (15.3 ± 0.1 and 15.4 ± 0.2 years; BMI: 33.0 ± 0.7 and 35.0 ± 1.0 kg/m(2), respectively). Immunoradiometric assays were used to measure IGF-1, IGFBP-1, and IGFBP-3. Total fat and soft lean tissue were measured by dual-energy X-ray absorptiometry and visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAAT), and hepatic fat fraction (HFF) were measured by magnetic resonance imaging. IGF-1 levels were 23.1% higher and IGFBP-1 were 40.4% higher in African Americans compared to Latinos after adjustment for total lean and total fat mass. IGF-1 and IGFBP-1 were inversely correlated with BMI, total fat mass, VAT, and HFF (r = -0.20 to -0.33, P < 0.05) while IGFBP-1 was inversely correlated with SAAT (r = -0.22, P < 0.05). These relationships did not differ by ethnicity, however, the relationship between IGF-1 and SAAT, as well as IGFBP-1 and HFF, differed by ethnicity. Predicted mean IGF-1 levels were 30.7% higher for African Americans at the 75th compared to 25th percentile of SAAT and only 11.7% higher for Latinos. Predicted mean IGFBP-1 levels were 158% higher for African Americans at the 25th compared to the 75th percentile of HFF while IGFBP-1 levels were 1.7% higher for Latinos at the 75th compared to the 25th percentile. These results demonstrate that the relationship between IGF-1 and SAAT as well as IGFBP-1 and HFF are different in African-American and Latino adolescents and may contribute to the higher IGF-1 levels in African-Americans.

Interventions for improving metabolic risk in overweight Latino youth

This review highlights various components of interventions that reduced obesity and type 2 diabetes risk factors among overweight Latino youth. A total of 114 overweight Latino adolescents completed one of four randomized controlled trials: 1) strength training (ST; boys only); 2) modified carbohydrate nutrition program (N); 3) combination of N+ST; or 4) N + Combination of Aerobic and ST (N+CAST; girls only). Measures included: strength by 1-repetition max, dietary intake by 3-d records, body composition by DEXA/MRI, glucose/insulin indices by oral and IV glucose tolerance tests. ST improved insulin sensitivity by 45% in Latino boys, and N, N+ST, and N+CAST improved glucose control in Latino boys and girls. The CAST approach reduced all adiposity measures by ∼3% in Latina girls. Participants who decreased added sugar, increased dietary fiber, and had increased parental attendance, regardless of intervention group, improved insulin action and reduced visceral adipose tissue. In conclusion, ST, CAST, and a modified carbohydrate nutrition program with separate parental classes were all successful components of the interventions that decreased obesity and related metabolic diseases.

Increased physical activity and reduced adiposity in overweight Hispanic adolescents

PURPOSE

The objectives of this study were to examine 1) whether changes in total physical activity (PA; counts per minute, cpm) and time spent in moderate to vigorous PA (MVPA) are associated with changes in adiposity and 2) whether energy intake influences the relationship between changes in PA and changes in adiposity in overweight Hispanic adolescents.

METHODS

Analysis included 38 overweight (body mass index, >85th percentile) Hispanic adolescents with complete pretest and posttest data on relevant variables after participating in a 16-wk intervention. The intervention treatment did not influence PA, so the sample was combined and the randomization group was adjusted for in the analysis. Body composition by dual-energy x-ray absorptiometry, 7-d PA by accelerometry, and dietary intake by 3-d diet records were assessed before and after intervention.

RESULTS

Within individuals, the mean increase of PA (n = 19) and mean decrease of PA (n = 19) was approximately 105 cpm. A 100-cpm increase in total PA was associated with a decrease of 1.3 kg of fat mass and 0.8% body fat after adjusting for pretest adiposity, PA, age, sex, and treatment (P < 0.05). Controlling for energy intake modestly strengthened the relationships between total PA and fat mass and percent body fat. Changes in MVPA were not related to changes in adiposity after controlling for total PA (P > 0.05).

CONCLUSIONS

Increasing total PA by 28% (100 cpm) was associated with a decrease of 1.4 kg of fat mass and 1% body fat for 16 wk in overweight Hispanic adolescents independent of intervention group assignment. Increases in total PA, compared with MVPA, may be sufficient to improve body composition in overweight Hispanic adolescents.

Dietary fiber and associations with adiposity and fasting insulin among college students with plausible dietary reports

OBJECTIVE

We examined dietary fiber intake, food sources of dietary fiber, and relation of dietary fiber to body composition and metabolic parameters in college students with plausible dietary reports.

METHODS

Students (18-24 y of age) provided data on anthropometry, fasting blood chemistries, and body composition (bioelectric impedance). Diet and physical activity were assessed with the Diet History Questionnaire and the International Physical Activity Questionnaire. Plausible dietary reporters were identified (+/-1 SD cutoffs for reported energy intake as a percentage of predicted energy requirement). Multiple regression analyses were conducted with the total (n = 298) and plausible (n = 123) samples, adjusting for age, race, sex, smoking status, physical activity, energy intake, and fat-free mass (where applicable).

RESULTS

Food sources of dietary fiber were similar in men and women. In the plausible sample compared with the total sample, dietary fiber was more strongly associated with fat mass (beta = -0.24, P < 0.001), percentage of body fat (beta = -0.23, P < 0.001), body mass index (beta = -0.11, P < 0.01), waist circumference (beta = -0.67, P < 0.05), and fasting insulin (beta = -0.15, P < 0.001). When the effect of sex was investigated, dietary fiber was inversely related to fasting insulin and fat mass in men and women and inversely related to percentage of body fat, body mass index, and waist circumference in men only (P < 0.05).

CONCLUSION

Inclusion of implausible dietary reports may result in spurious or weakened diet-health associations. Dietary fiber is negatively associated with fasting insulin levels in men and women and consistently associated with adiposity measurements in men.

Randomized control trial to improve adiposity and insulin resistance in overweight Latino adolescents

Few randomized trials attempt to improve insulin sensitivity and associated metabolic risks in overweight Latino youth. The purpose of this study is to examine the effects of a modified carbohydrate nutrition program combined with strength training on insulin sensitivity, adiposity, and other type 2 diabetes risk factors in overweight Latino adolescents. In a 16-week randomized trial, 54 overweight Latino adolescents (15.5 +/- 1.0 years) were randomly assigned to: (i) Control (C; n = 16), (ii) Nutrition (N; n = 21), or (iii) Nutrition + Strength training (N+ST; n = 17). The N group received modified carbohydrate nutrition classes (once per week), while the N+ST received the same nutrition classes plus strength training (twice per week). The following were measured at pre- and postintervention: strength by 1-repetition maximum, dietary intake by 3-day records, body composition by dual-energy X-ray absorptiometry, glucose/insulin indices by oral glucose tolerance test (OGTT) and intravenous glucose tolerance test with minimal modeling. Across intervention group effects were tested using analysis of covariance with post hoc pairwise comparisons. A significant overall intervention effect was found for improvement in bench press (P < 0.001) and reductions in energy (P = 0.05), carbohydrate (P = 0.04) and fat intake (P = 0.03). There were no significant intervention effects on insulin sensitivity, body composition, or most glucose/insulin indices with the exception of glucose incremental area under the curve (IAUC) (P = 0.05), which decreased in the N and N+ST group by 18 and 6.3% compared to a 32% increase in the C group. In conclusion, this intense, culturally tailored intervention resulted in no significant intervention effects on measured risk factors with the exception of a beneficial effect on glycemic response to oral glucose.

Aerobic and strength training reduces adiposity in overweight Latina adolescents

PURPOSE

To date, no study has examined the synergistic effects of a nutrition and combination of aerobic and strength training (CAST) on both adiposity and metabolic parameters in overweight Latina adolescent females. The goal was to assess if a 16-wk nutrition plus CAST pilot study had stronger effects on reducing adiposity and on improving glucose/insulin indices compared with control (C), nutrition only (N), and a nutrition plus strength training (N + ST) groups.

METHODS

In a 16-wk randomized trial, 41 overweight Latina girls (15.2 +/- 1.1 yr) were randomly assigned to C (n = 7), N (n = 10), N + ST (n = 9), or N + CAST (n = 15). All intervention groups received modified carbohydrate nutrition classes (once a week), whereas the N + ST also received strength training (twice a week) and the N + CAST received a combination of strength and aerobic training (twice a week). The following were measured before and after intervention: strength by one repetition maximum, physical activity by the 7-d accelerometry and the 3-d physical activity recall, dietary intake by 3-d records, body composition by dual-energy x-ray absorptiometry (DEXA), glucose/insulin indices by oral glucose tolerance test, and intravenous glucose tolerance test with minimal modeling. Across intervention group, effects were tested using ANCOVA with post hoc pairwise comparisons.

RESULTS

There were significant overall intervention effects for all adiposity measures (weight, body mass index [BMI], BMI z-scores, and DEXA total body fat), with a decrease of 3% in the N + CAST group compared with a 3% increase in the N + ST group (P < or = 0.05). There was also an intervention effect for fasting glucose with the N group increasing by 3% and the N + CAST group decreasing by 4% (P < or = 0.05).

CONCLUSION

The CAST was more effective than nutrition alone or nutrition plus strength training for reducing multiple adiposity outcomes and fasting glucose in overweight Latina girls. However, further research investigating and identifying intervention approaches that improve both adiposity and insulin indices, particularly in high-risk populations, are warranted.

Birth weight and body composition in overweight Latino youth: a longitudinal analysis

To examine the associations between birth weight and BMI, and total body composition, in overweight Latino adolescents. Two hundred and forty-two overweight Latino children (baseline age = 11.1 +/- 1.7 years; BMI >or= 85th percentile) were measured annually for up to 6 years (2.6 +/- 1.4 observations/child, total 848 visits). Birth weight and history of gestational diabetes were obtained by parental interview. Visceral fat and subcutaneous abdominal fat were assessed by magnetic resonance imaging, while total body fat, total lean tissue mass (LTM), trunk fat, and lean tissue trunk mass were measured by dual-energy X-ray absorptiometry. BMI and BMI percentile were calculated using the Centers for Disease Control and Prevention age appropriate cutoffs. Longitudinal linear mixed effects (LME) modeling was used to evaluate the influence of birth weight on subsequent changes in body composition and distribution of fat across puberty. Birth weight significantly predicted BMI (P < 0.001), total trunk fat (P < 0.001), total trunk LTM (P < 0.001), total fat mass (FM) (P < 0.001), and total LTM (P < 0.001), but not subcutaneous (P = 0.534) or visceral fat (P = 0.593) at age 11 years. Longitudinally, as participants transitioned into puberty, birth weight did not significantly predict any of the body composition or fat distribution measures (P > 0.05). Birth weight is significantly associated with increased adiposity and LTM and negatively associated with trunk fat mass and trunk lean mass at baseline; however these relationships did not predict rate of change of any of the variables as the children progress through adolescence.

Cardiorespiratory fitness predicts changes in adiposity in overweight Hispanic boys

We have previously shown that cardiorespiratory fitness predicts increasing fat mass during growth in white and African-American youth, but limited data are available examining this issue in Hispanic youth. Study participants were 160 (53% boys) overweight (BMI>or=85th percentile for age and gender) Hispanic children (mean+/-s.d. age at baseline=11.2+/-1.7 years). Cardiorespiratory fitness, assessed by VO2max, was measured through a maximal effort treadmill test at baseline. Body composition through dual-energy X-ray absorptiometry and Tanner stage through clinical exam were measured at baseline and annually thereafter for up to 4 years. Linear mixed models were used to examine the gender-specific relationship between VO2max and increases in adiposity (change in fat mass independent of change in lean tissue mass) over 4 years. The analysis was adjusted for changes in Tanner stage, age, and lean tissue mass. In boys, higher VO2max at baseline was inversely associated with the rate of increase in adiposity (beta=-0.001, P=0.03); this effect translates to a 15% higher VO2max at baseline resulting in a 1.38 kg lower fat mass gain over 4 years. However, VO2max was not significantly associated with changes in fat mass in girls (beta=0.0002, P=0.31). In overweight Hispanic boys, greater cardiorespiratory fitness at baseline was protective against increasing adiposity. In girls however initial cardiorespiratory fitness was not significantly associated with longitudinal changes in adiposity. These results suggest that cardiorespiratory fitness may be an important determinant of changes in adiposity in overweight Hispanic boys but not in girls.

Associations of dietary sugar and glycemic index with adiposity and insulin dynamics in overweight Latino youth

BACKGROUND

Few studies have examined the relation between dietary carbohydrate quality, adiposity, and insulin dynamics in children.

OBJECTIVE

The objective of the study was to determine which aspects of dietary carbohydrate, specifically dietary sugar, fiber, glycemic index, or glycemic load, are associated with adiposity and insulin dynamics in overweight Latino children.

DESIGN

We examined 120 overweight Latino children (10-17 y old) with a family history of type 2 diabetes. Dietary intake was determined by repeated 24-h diet recalls. Adiposity was assessed by using total-body dual-energy X-ray absorptiometry. Insulin dynamics [insulin sensitivity (SI), acute insulin response, and disposition index (an index of beta-cell function)] were measured by using a frequently sampled intravenous-glucose-tolerance test.

RESULTS

After adjustment for covariates, total sugar (g/d) was positively correlated with body mass index (BMI; in kg/m(2)), BMI z scores, and total fat mass (r = 0.20, r = 0.22, and r = 21, respectively; P < 0.05) and negatively correlated with SI and disposition index (r = -0.29 and r = -0.24, respectively; P < 0.05). Dietary fiber, glycemic index, and glycemic load were not significantly correlated with adiposity or insulin dynamics before or after control for covariates. Regression analyses showed that total sugar intake explained an additional 3.4%, 4.6%, and 2.4% of the variance in BMI, BMI z scores, and total fat mass, respectively, and an additional 5.6% and 4.8% of the variance in SI and disposition index (P < 0.05), respectively, after control for covariates.

CONCLUSION

In this cohort, total sugar intake, rather than glycemic index or glycemic load, was associated with higher adiposity measures, lower SI, and lower measures of insulin secretion.