Purpose To describe physical activity (PA) levels by race/ethnicity, age, gender, and weight status in a representative sample of U.S. youth. Methods Cross-sectional data from the 2003–4 and 2005–6 National Health and Nutrition Examination Survey (NHANES) were combined and analyzed. Youth ages 6 to 19 with at least 4 10-hour days of PA measured by accelerometry were included (N=3,106). Outcomes included mean counts per minute and minutes spent in moderate to vigorous PA (MVPA). Results 6 to 11 year olds spent more time (88 min/day) in MVPA than 12 to 15 (33 min/day) and 16–19 (26 min/day) year olds (p<.001 for both). Females spent fewer min/day in MVPA than males (p<.001). Overall, obese youth spent 16 fewer min/day in MVPA than normal weight youth. However, non-Hispanic White (NHW) males spent 3–4 fewer min/day in vigorous PA than Mexican American (MA) (p=.004) and non-Hispanic Black (NHB) (p<.001) males but had lower obesity rates; and obese 12 to 15 year old MA recorded similar minutes in MVPA per day as normal weight MA (p>.050). There was a significant 3-way age-BMI-race/ethnicity interaction for mean min/day in MVPA (p<.001). Adjustment for total energy intake did not qualitatively alter these results. Conclusion Females and older youth were the least active groups. Obese youth were generally less active, but this did not hold uniformly across race/ethnic groups. Cultural or biological factors could moderate the association between PA and obesity in youth.

Interrupting sedentary time with brief moderate-intensity walking improved short-term metabolic function in non-overweight children without increasing subsequent energy intake. These findings suggest that interrupting sedentary behavior may be a promising prevention strategy for reducing cardiometabolic risk in children.

Parents exert a strong influence on their children's diet. While authoritative parenting style is linked to healthier weight and dietary outcomes in children, and authoritarian and permissive parenting styles with unhealthy eating, little is known about the mechanisms that mediate these relationships. Feeding styles are often examined in relation to child diet, but they do not consider the social and physical environmental contexts in which dietary behaviors occur. Therefore, this study examined whether parenting styles (authoritative, authoritarian, and permissive) were associated with three specific food-related parenting practices - mealtime structural practices (e.g., eating meals as a family), parent modeling of healthy food, and household food rules and whether these parenting practices mediated the association between parenting styles and children's diet. Participants were 174 mother-child dyads. Mothers (68% married, 58% college graduates, M = 41 years [SD = 6.2]) reported on their parenting practices using validated scales and parenting style using the Parenting Styles and Dimensions Questionnaire. Children (52% female, M = 10 years [SD = 0.9]) completed two telephone-based 24-hour dietary recalls. Dietary outcomes included the Healthy Eating Index (HEI)-2010 score, and fruit and vegetables and added sugar intake. Using PROCESS, multiple mediation cross-sectional analyses with parallel mediators using 10,000 bootstraps were performed. Significant indirect effects were observed with mealtime structure and the relationships between authoritative parenting and HEI-2010 score (b = 0.045, p < .05, CI = [0.006, 0.126]), authoritarian parenting and HEI-2010 score (b = -0.055, p < .05, CI = [-0.167, -0.001]), and permissive parenting and HEI-2010 score (b = -0.093, p < .05, CI = [-0.265, -0.008]). Child diet quality is affected by mealtime structural practices. Further examination of the features by which mealtime structural practices serve as a mechanism for parents to support healthy eating among their children may improve children's diet quality.

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.

units (MIMS-units) from raw triaxial accelerometer data were used. We removed the partial first and last assessment days and days with ≥5% nonwear time. Participants with ≥1 valid day were included. Mean MIMS-units were calculated across all valid days. Percentile tables and smoothed curves of daily MIMS-units were calculated for each age and sex using the Generalized Additive Models for Location Shape and Scale. Results: The analytical sample included 14,705 participants age ≥3 yr. The MIMS-unit activity among youth was similar for both sexes, whereas adult females generally had higher MIMS-unit activity than did males. Median daily MIMS-units peaked at age 6 yr for both sexes (males, 20,613; females, 20,706). Lowest activity was observed for males and females 80+ yr of age: 8799 and 9503, respectively. Conclusions: Population referenced MIMS-unit percentiles for US youth and adults are a novel means of characterizing total activity volume. By using MIMS-units, we provide a standardized reference that can be applied across various wrist-worn accelerometer devices. Further work is needed to link these metrics to activity intensity categories and health outcomes.

Low adherence to guidelines for weight-related behaviors (e.g., dietary intake and physical activity) among U.S. children underscores the need to better understand how parental factors may influence children’s obesity risk. In addition to most often acting as primary caregiver to their children, women are also known to experience greater levels of stress than men. This study systematically reviewed associations between maternal stress and children’s weight-related behaviors. Our search returned 14 eligible articles, representing 25 unique associations of maternal stress with a distinct child weight-related behavior (i.e., healthy diet (n=3), unhealthy diet (n=6), physical activity (n=7), sedentary behavior (n=9)). Overall, findings for the relationship between maternal stress and children’s weight-related behaviors were mixed, with no evidence for an association with children’s healthy or unhealthy dietary intake, but fairly consistent evidence for the association of maternal stress with children’s lower physical activity and higher sedentary behavior. Recommendations for future research include prioritizing prospective designs, identifying moderators, and use of high resolution, real-time data collection techniques to elucidate potential mechanisms.

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Background:A profound decline in physical activity occurs in puberty. This phenomenon is not well understood. Therefore, the purpose of this study is to examine associations between family/friend social support for physical activity, negative meanings of physical activity (NMPA), and internal /external barriers to physical activity with moderate to vigorous physical activity (MVPA), and sedentary and light behavior (SLB) in youth.Methods:A total of 350 participants from 7 Los Angeles County middle schools participated in the study (62% Latina, 79% females). Hypothesized pathways were examined using structural equation modeling. Psychosocial variables and participation in MVPA and SLB were assessed by self-reported questionnaires.Results:NMPA were related to lower levels of family/friend social support and greater internal/external barriers. Family social support was the only significant indicator of MVPA (β = 0.79). Low family social support was related to higher SLB (β = −0.25).Conclusions:Family social support seems crucial to promote MVPA and reduce SLB in adolescents and might be influenced by child’s feelings about physical activity. Future research should consider the interrelationship between psychosocial correlates of physical activity.