Jason A. Mendoza

Television viewing, computer use, obesity, and adiposity in US preschool children

BackgroundThere is limited evidence in preschool children linking media use, such as television/video viewing and computer use, to obesity and adiposity. We tested three hypotheses in preschool children: 1) that watching > 2 hours of TV/videos daily is associated with obesity and adiposity, 2) that computer use is associated with obesity and adiposity, and 3) that > 2 hours of media use daily is associated with obesity and adiposity.MethodsWe conducted a cross-sectional study using nationally representative data on children, aged 2–5 years from the National Health and Nutrition Examination Survey, 1999–2002. Our main outcome measures were 1) weight status: normal versus overweight or at risk for overweight, and 2) adiposity: the sum of subscapular and triceps skinfolds (mm). Our main exposures were TV/video viewing (≤ 2 or > 2 hours/day), computer use (users versus non-users), and media use (≤ 2 or > 2 hours/day). We used multivariate Poisson and linear regression analyses, adjusting for demographic covariates, to test the independent association between TV/video viewing, computer use, or overall media use and a childs weight status or adiposity.ResultsWatching > 2 hours/day of TV/videos was associated with being overweight or at risk for overweight (Prevalence ratio = 1.34, 95% CI [1.07, 1.66]; n =1340) and with higher skinfold thicknesses (β = 1.08, 95% CI [0.19, 1.96]; n = 1337). Computer use > 0 hours/day was associated with higher skinfold thicknesses (β = 0.56, 95% CI [0.04, 1.07]; n = 1339). Media use had borderline significance with higher skinfold thicknesses (β = 0.85, 95% CI [-0.04, 1.75], P=0.06; n = 1334)ConclusionWatching > 2 hours/day of TV/videos in US preschool-age children was associated with a higher risk of being overweight or at risk for overweight and higher adiposity–findings in support of national guidelines to limit preschool childrens media use. Computer use was also related to higher adiposity in preschool children, but not weight status. Intervention studies to limit preschool childrens media use are warranted.

Prevalence of Metabolic Syndrome and Obesity in Adolescents Aged 12 to 19 Years: Comparison between the United States and Korea

This study compared the prevalence of metabolic syndrome (MetS), its risk factors, and obesity in adolescents in the United States (US) and Korea. Data were obtained from 2003-2004 US National Health and Nutrition Examination Survey (NHANES) and 2005 Korea NHANES for adolescents aged 12-19 yr in the US (n=734) and in Korea (n=664). The 2007 International Diabetes Federation (IDF) pediatric definition for diagnosis of MetS and the 2000 US Growth Charts and 2007 Korea Growth Charts for assessment of obesity were utilized. The prevalence of metabolic syndrome in US and Koreans was 5.5% and 2.5%, respectively. The prevalence of obesity was 18.1% in US compared to 9.0% in Koreans. The prevalence of abdominal obesity, hyperglycemia, and hypertriglyceridemia were higher in the US, whereas that of low HDL-C levels was higher in Korea. Despite the doubled prevalence for the single entities of MetS and obesity in the US, the prevalence of MetS in obese US and Koreans did not differ (20.8% and 24.3%, respectively). In conclusion, there are differences in the prevalence of MetS, obesity, and the individual MetS risk factors between the US and Korean adolescents; however, the risk of MetS among obese adolescents is similar in both countries.

The Walking School Bus and Children's Physical Activity: A Pilot Cluster Randomized Controlled Trial

OBJECTIVE: To evaluate the impact of a “walking school bus” program on childrens rates of active commuting to school and physical activity. METHODS: We conducted a pilot cluster randomized controlled trial among 4th-graders from 8 schools in Houston, Texas (N = 149). Random allocation to treatment or control conditions was at the school level. Study staff walked with children to and from school up to 5 days/week. Outcomes were measured the week before (time 1) and during weeks 4 and 5 of the intervention (time 2). The main outcome was the weekly rate of active commuting, and a secondary outcome was moderate-to-vigorous physical activity. Covariates included sociodemographics, distance from home to school, neighborhood safety, child BMI z score, parent self-efficacy/outcome expectations, and child self-efficacy for active commuting. A mixed-model repeated measures regression accounted for clustering by school, and stepwise procedures with backward elimination of nonsignificant covariates were used to identify significant predictors. RESULTS: Intervention children increased active commuting (mean ± SD) from 23.8% ± 9.2% (time 1) to 54% ± 9.2% (time 2), whereas control subjects decreased from 40.2% ± 8.9% (time 1) to 32.6% ± 8.9% (time 2) (P < .0001). Intervention children increased their minutes of daily moderate-to-vigorous physical activity from 46.6 ± 4.5 (time 1) to 48.8 ± 4.5 (time 2), whereas control children decreased from 46.1 ± 4.3 (time 1) to 41.3 ± 4.3 (time 2) (P = .029). CONCLUSIONS: The program improved childrens active commuting to school and daily moderate-to-vigorous physical activity.

Houston. We Have a Problem! Measurement of Parenting

Obesity is a dominant child health problem in the United States1 and virtually worldwide.2 Obesity in childhood is associated with a number of negative health outcomes,3,4 with substantially increased risk of adult obesity.5 The energy balance model indicates obesity is the result of overconsumption of calories, low levels of physical activity, and high levels of sedentary behavior, mostly high screen time (TV, videos, and videogames).6

Physical Activity Parenting Measurement and Research: Challenges, Explanations, and Solutions

Physical activity (PA) parenting research has proliferated over the past decade, with findings verifying the influential role that parents play in childrens emerging PA behaviors. This knowledge, however, has not translated into effective family-based PA interventions. During a preconference workshop to the 2012 International Society for Behavioral Nutrition and Physical Activity annual meeting, a PA parenting workgroup met to: (1) Discuss challenges in PA parenting research that may limit its translation, (2) identify explanations or reasons for such challenges, and (3) recommend strategies for future research. Challenges discussed by the workgroup included a proliferation of disconnected and inconsistently measured constructs, a limited understanding of the dimensions of PA parenting, and a narrow conceptualization of hypothesized moderators of the relationship between PA parenting and child PA. Potential reasons for such challenges emphasized by the group included a disinclination to employ theory when developing measures and examining predictors and outcomes of PA parenting as well as a lack of agreed-upon measurement standards. Suggested solutions focused on the need to link PA parenting research with general parenting research, define and adopt rigorous standards of measurement, and identify new methods to assess PA parenting. As an initial step toward implementing these recommendations, the workgroup developed a conceptual model that: (1) Integrates parenting dimensions from the general parenting literature into the conceptualization of PA parenting, (2) draws on behavioral and developmental theory, and (3) emphasizes areas which have been neglected to date including precursors to PA parenting and effect modifiers.

Environmental and cultural correlates of physical activity parenting practices among Latino parents with preschool-aged children: Niños Activos.

BackgroundLatino children are at high risk of becoming obese. Physical activity (PA) can help prevent obesity. Parents can influence children’s PA through parenting practices. This study aimed to examine the independent contributions of (1) sociodemographic, (2) cultural, (3) parent perceived environmental, and (4) objectively measured environmental factors, to PA parenting practices.MethodsA cross-sectional sample of Latino parents (n = 240) from Harris County, TX in 2011–2012 completed validated questionnaires to assess PA parenting practices, acculturation, familism, perception of their neighborhood environment, and demographics. Home addresses were mapped and linked to Census block-level crime and traffic data. Distance to the closest park was mapped by GIS. Regression models were built in a hierarchical step-wise fashion.ResultsCombined models showed R2 of 6.8% to 38.9% for different parenting practices. Significant correlations included sociodemographic variables with having outdoor toys available, psychological control, and promotion of inactivity. Cultural factors correlated with PA safety concern practices. Perceived environmental attributes correlated with five of seven parenting practices, while objectively-measured environmental attributes did not significantly correlate with PA parenting practices.ConclusionInterventions promoting PA among Latino preschoolers may need to address the social-ecological context in which families live to effectively promote PA parenting, especially parents’ perceptions of neighborhoods.

Psychometrics of the preschooler physical activity parenting practices instrument among a Latino sample

BackgroundLatino preschoolers (3-5 year old children) have among the highest rates of obesity. Low levels of physical activity (PA) are a risk factor for obesity. Characterizing what Latino parents do to encourage or discourage their preschooler to be physically active can help inform interventions to increase their PA. The objective was therefore to develop and assess the psychometrics of a new instrument: the Preschooler Physical Activity Parenting Practices (PPAPP) among a Latino sample, to assess parenting practices used to encourage or discourage PA among preschool-aged children.MethodsCross-sectional study of 240 Latino parents who reported the frequency of using PA parenting practices. 95% of respondents were mothers; 42% had more than a high school education. Child mean age was 4.5 (±0.9) years (52% male). Test-retest reliability was assessed in 20%, 2 weeks later. We assessed the fit of a priori models using Confirmatory factor analyses (CFA). In a separate sub-sample (35%), preschool-aged children wore accelerometers to assess associations with their PA and PPAPP subscales.ResultsThe a-priori models showed poor fit to the data. A modified factor structure for encouraging PPAPP had one multiple-item scale: engagement (15 items), and two single-items (have outdoor toys; not enroll in sport-reverse coded). The final factor structure for discouraging PPAPP had 4 subscales: promote inactive transport (3 items), promote screen time (3 items), psychological control (4 items) and restricting for safety (4 items). Test-retest reliability (ICC) for the two scales ranged from 0.56-0.85. Cronbach’s alphas ranged from 0.5-0.9. Several sub-factors correlated in the expected direction with children’s objectively measured PA.ConclusionThe final models for encouraging and discouraging PPAPP had moderate to good fit, with moderate to excellent test-retest reliabilities. The PPAPP should be further evaluated to better assess its associations with children’s PA and offers a new tool for measuring PPAPP among Latino families with preschool-aged children.

Impact of a pilot walking school bus intervention on children's pedestrian safety behaviors: A pilot study

Walking school buses (WSB) increased childrens physical activity, but impact on pedestrian safety behaviors (PSB) is unknown. We tested the feasibility of a protocol evaluating changes to PSB during a WSB program. Outcomes were school-level street crossing PSB prior to (Time 1) and during weeks 4-5 (Time 2) of the WSB. The protocol collected 1252 observations at Time 1 and 2548 at Time 2. Mixed model analyses yielded: intervention schoolchildren had 5-fold higher odds (p<0.01) of crossing at the corner/crosswalk but 5-fold lower odds (p<0.01) of stopping at the curb. The protocol appears feasible for documenting changes to school-level PSB.

Characterizing lunch meals served and consumed by pre-school children in Head Start

OBJECTIVE To examine the variability of food portions served and consumed by African-American and Hispanic-American pre-school children attending Head Start. DESIGN Cross-sectional. SETTING Food consumption by pre-schoolers (n 796) enrolled in sixteen Head Start centres in Houston, Texas (51 % boys, 42 % African-American, mean age 4 years) were assessed during 3 d of lunch meals using digital photography. Descriptive statistics and multilevel regression models, adjusting for classroom and school clustering effects, were determined. SUBJECTS Head Start pre-schoolers aged 3–5 years. RESULTS Mean amount served was 2428 kJ (580 kcal) and 572 g. Mean intake was 1421 kJ (339 kcal) and 331 g: 20 % protein, 46 % carbohydrate and 34 % fat. Plate waste was 43 % (range: 38 % (fruit) to 61 % (vegetables)). Mean CV of food served was 29 %: 33 % for entrées, 44 % for vegetables, 60 % for fruit and 76 % for starches. Mean CV of food consumed was 46 %: 58 % for entrées, 86 % for fruit, 96 % for vegetables and 111 % for starches. Total gram amount of food served was positively correlated with consumption (r = 0·43, P < 0·001). CONCLUSIONS Plate waste and variation in amounts served and consumed were substantial; amounts served were associated with amounts consumed. Large portion sizes may contribute to paediatric obesity by promoting excessive intake at meals. Understanding factors influencing portion sizes provides insight about specific intervention strategies that can be used in obesity prevention programmes.

Texting to Increase Physical Activity Among Teenagers (TXT Me!): Rationale, Design, and Methods Proposal

Background Physical activity decreases from childhood through adulthood. Among youth, teenagers (teens) achieve the lowest levels of physical activity, and high school age youth are particularly at risk of inactivity. Effective methods are needed to increase youth physical activity in a way that can be maintained through adulthood. Because teens text a great deal, text messages promoting walking, a low cost physical activity, may be an effective method for promoting sustainable physical activity. Objective The objective of our study was to determine the effect of pedometers, self selected step goals, and texts grounded in the self-determination theory (SDT) on physical activity among the teens. Methods “TXT Me!” was a 12 week intervention that texted 14-17 year olds to increase their daily physical activity by increasing the number of steps they take each day. The intervention was grounded in the SDT. Formative research with the teens helped construct the intervention and develop the texts. A total of 84 texts were developed (12 to set a step goal, and 72 promoting autonomy, competence, and relatedness). The pilot evaluation used a four group, randomized design (n=160). After baseline data collection, the participants were randomized to one of four conditions (no treatment control, pedometer only, pedometer + weekly prompts, pedometer + weekly prompts + SDT grounded texts). Data were collected at baseline and immediately upon completion of the study. The primary outcome was physical activity, measured by 7 days of accelerometry. Basic psychological needs, physical activity motivation, process evaluation, and program satisfaction data were also collected. Results To our knowledge, this is one of the first studies to explore the use of stand alone, SDT grounded texts, supported by pedometers and prompts to set a self selected step goal, as a method for increasing physical activity among teens. Conclusions This pilot study will contribute valuable information regarding whether theoretically grounded text messages show promise as an effective method to increase physical activity among teens. Trial Registration Clinicaltrials.gov NCT01482234; http://clinicaltrials.gov/ct2/show/NCT01482234 (Archived by WebCite at http://www.webcitation.org/6NYvRMOoq).