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

Television viewing by young Hispanic children: evidence of heterogeneity

OBJECTIVES

To determine if hours of daily television viewed by varying age groups of young children with Hispanic mothers differs by maternal language preference and to compare these differences with young children with white mothers.

DESIGN

Cross-sectional analysis of data collected in 2000 from the National Survey of Early Childhood Health.

SETTING

Nationally representative sample.

PARTICIPANTS

One thousand three hundred forty-seven mothers of children aged 4 to 35 months.

MAIN EXPOSURE

Subgroups of self-reported maternal race/ethnicity (white or Hispanic) and within Hispanic race/ethnicity, stratification by maternal language preference (English or Spanish).

OUTCOME MEASURE

Hours of daily television the child viewed.

RESULTS

Bivariate analyses showed that children of English- vs Spanish-speaking Hispanic mothers watched more television daily (1.88 vs 1.31 hours, P < .01). Multivariable regression analyses stratified by age revealed differences by age group. Among 4- to 11-month-old infants, those of English- and Spanish-speaking Hispanic mothers watched similar amounts. However, among children aged 12 to 23 and 24 to 35 months, those of English-speaking Hispanic mothers watched more television than children of Spanish-speaking Hispanic mothers (incidence rate ratio [IRR], 1.61; 95% confidence interval [CI], 1.17-2.22; IRR, 1.66; 95% CI, 1.10-2.51, respectively). Compared with children of white mothers, children of both Hispanic subgroups watched similar amounts among the 4- to 11-month-old group. However, among 12- to 23-month-old children, those of English-speaking Hispanic mothers watched more compared with children of white mothers (IRR, 1.57; 95% CI, 1.18-2.11). Among 24- to 35-month-old children, those of English-speaking Hispanic mothers watched similar amounts compared with children of white mothers, but children of Spanish-speaking Hispanic mothers watched less (IRR, 0.69; 95% CI, 0.50-0.95).

CONCLUSION

Television-viewing amounts among young children with Hispanic mothers vary by child age and maternal language preference, supporting the need to explore sociocultural factors that influence viewing in Hispanic children.

Obesity and television watching in preschoolers in Greece: the GENESIS study

The aim of the current work was to evaluate the effect of preschoolers' television (TV) watching time on the prevalence of obesity even after controlling for their total energy intake and their physical activity status. A representative sample of 2,374 Greek children aged 1-5 years was examined ("Growth, Exercise and Nutrition Epidemiological Study in preSchoolers", GENESIS study). Children's TV watching time on a usual weekday and at a usual weekend was recorded. The overall mean of children's TV viewing time was 1.32 h/day. The majority of participants (74.0%) spent <2 h/day watching TV whereas only 3.1% spent >4 h/day in front of a TV set. Overall, 65.2% of participants were normal weight, 17.2% were overweight, and the rest 17.6% were obese. The prevalence of obesity was significantly higher among those with TV viewing time >or=2 h/day (21.7%) compared to those watching TV <2 h/day (16.1%, P = 0.003). TV viewing time remained significantly associated with the likelihood of being obese even after controlling for potential confounders (i.e., socio demographic and other characteristics and physical activity status) only among children aged 3-5 years. However, further adjusting for children's total energy intake revealed that the association between the TV viewing time and the probability of being obese was no longer statistically significant. On the other hand, physical activity status continued to be an independent factor of being obese. The current findings support the hypothesis that the effect of TV viewing time on childhood obesity is independent of physical activity status and may be attributed to the increased total energy intake during TV watching.

Screen time and adiposity in adolescents in Mexico

OBJECTIVE

To assess the association of time spent viewing television, videos and video games with measures of fat mass (BMI) and distribution (triceps and subscapular skinfold thicknesses (TSF, SSF)).

DESIGN

Cross-sectional validated survey, self-administered to students to assess screen time (television, videos and video games) and lifestyle variables. Trained personnel obtained anthropometry. The association of screen time with fat mass and distribution, stratified by sex, was modelled with multivariable linear regression analysis, adjusting for potential confounders and correlation of observations within schools.

SETTING

State of Morelos, Mexico.

SUBJECTS

Males (n 3519) and females (n 5613) aged 11 to 18 years attending urban and rural schools in Morelos.

RESULTS

In males, screen time of >5 h/d compared with <2 h/d was significantly associated with a 0.13 (95% CI 0.04, 0.23) higher BMI Z-score, 0.73 mm (95% CI 0.24, 1.22) higher SSF and 1.08 mm (95% CI 0.36, 1.81) higher TSF. The positive association of screen time with SSF was strongest in males aged 11-12 years. Sexual maturity appeared to modify the association in females; a positive association between screen time and SSF was observed in those who had not undergone menarche (P for trend = 0.04) but not among sexually mature females (P for trend = 0.75).

CONCLUSION

Screen time is associated with fat mass and distribution among adolescent males in Mexico. Maturational tempo appears to affect the relationship of screen time with adiposity in boys and girls. Findings suggest that obesity preventive interventions in the Mexican context should explore strategies to reduce screen time among youths in early adolescence.

Early child care and adiposity at ages 1 and 3 years

BACKGROUND

The majority of infants in the United States are in nonparental child care, yet little is known about the effect of child care on development of obesity.

OBJECTIVE

To examine the relationship between child care attendance from birth to 6 months and adiposity at 1 and 3 years of age.

METHODS

We studied 1138 children from a prospective cohort of pregnant women and their offspring. The main exposure was time in child care from birth to 6 months of age, overall and by type of care: (1) child care center; (2) someone else's home; and (3) child's own home by nonparent. The main outcomes were weight-for-length (WFL) z score at 1 year and BMI z score at 3 years of age.

RESULTS

A total of 649 (57%) infants attended child care; 17% were cared for in a center, 27% in someone else's home, and 21% in their own home by a nonparent. After adjustment for confounders, overall time in child care was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age but not skinfold thicknesses. Center and own home care were not associated with the outcomes, but care in someone else's home was associated with an increase in both the 1- and 3-year outcomes.

CONCLUSION

Child care in the first 6 months of life, especially in someone else's home, was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age.

Television viewing and food habits in toddlers and preschoolers in Greece: the GENESIS study

The aim of the current study was to evaluate the association between television (TV) viewing time and dietary habits of preschoolers. A representative sample of 2,374 Greek children aged 1-5 years was examined (GENESIS study). The majority of participants (74.0%) spent less than 2 h/day watching TV. Children spending > or =2 h/day watching TV seem to have higher energy intake compared to children watching TV less than 2 h/day, even after adjustment for potential confounders (p < 0.001). Furthermore, it was detected that the former were more likely to consume more than 5, 2, and 1.5 exchanges of fat, meat, and other carbohydrates per day, respectively, compared to the latter. In conclusion, the current findings indicate that prolonged TV viewing time may be associated with increased consumption of high-fat and high-sugar foods resulting in increased daily energy intake. Therefore, interventions aiming to modify children's TV viewing behaviour might need to be implemented.

Factors associated with television viewing time in toddlers and preschoolers in Greece: the GENESIS study

BACKGROUND

The aim of this work was to describe the television (TV) viewing time of preschoolers and to examine factors that may be associated with it.

METHODS

A representative sample of 2374 Greek children aged 1-5 years was examined (GENESIS study). Several anthropometric, socio-demographic and lifestyle characteristics were recorded.

RESULTS

The mean value of children's TV viewing time was 1.32 h/day. Twenty six percent of participants spent > or =2 h/day in TV viewing. The percentage of children whose TV viewing time was longer than 2 h/day was higher in children aged 3-5 years (32.2%) than in those aged 1-2 years (11.1%). Multiple logistic regression revealed that the time parents spent viewing TV and the region of residence were significantly associated with child's TV viewing time among children aged 3-5 years. Among children aged 1-2 years, the maternal educational status, the region of residence and the maternal TV viewing time were found to be related to child's TV viewing time.

CONCLUSIONS

The current findings suggest that almost one third of Greek preschoolers exceed the limit of 2 h/day TV viewing and that parental TV viewing time may be the most important determinant of children's TV viewing time.

Adiposity and TV viewing are related to less bone accrual in young children

OBJECTIVE

To examine the relation between baseline fat mass and gain in bone area and bone mass in preschoolers studied prospectively for 4 years, with a focus on the role of physical activity and TV viewing.

STUDY DESIGN

Children were part of a longitudinal study in which measures of fat, lean and bone mass, height, weight, activity, and diet were taken every 4 months from ages 3 to 7 years. Activity was measured by accelerometer and TV viewing by parent checklist. We included 214 children with total body dual energy x-ray absorptiometry (Hologic 4500A) scans at ages 3.5 and 7 years.

RESULTS

Higher baseline fat mass was associated with smaller increases in bone area and bone mass over the next 3.5 years (P < .001). More TV viewing was related to smaller gains in bone area and bone mass accounting for race, sex, and height. Activity by accelerometer was not associated with bone gains.

CONCLUSIONS

Adiposity and TV viewing are related to less bone accrual in preschoolers.

Active play and screen time in US children aged 4 to 11 years in relation to sociodemographic and weight status characteristics: a nationally representative cross-sectional analysis

BACKGROUND

The high prevalence of childhood obesity underscores the importance of monitoring population trends in children's activity and screen time, and describing associations with child age, gender, race/ethnicity, and weight status. Our objective was to estimate the proportion of young children in the US who have low levels of active play or high levels of screen time, or who have both these behaviors, and to describe associations with age, gender, race/ethnicity, and weight status.

METHODS

We analyzed data collected during the National Health and Nutrition Examination Surveys 2001-2004, a US nationally representative cross-sectional study. We studied 2964 children aged 4.00 to 11.99 years. Our main outcomes were reported weekly times that the child played or exercised hard enough to sweat or breathe hard (active play), daily hours the child watched television/videos, used computers, or played computer games (screen time), and the combination of low active play and high screen time. Low active play was defined as active play 6 times or less per week. High screen time was defined as more than 2 hours per day. We accounted for the complex survey design in analyses and report proportions and 95% confidence intervals. We used Wald Chi-square to test for differences between proportions. To identify factors associated with low active play and high screen time, we used multivariate logistic regression.

RESULTS

Of US children aged 4 to 11 years, 37.3% (95% confidence interval, 34.1% to 40.4%) had low levels of active play, 65.0% (95% CI, 61.4% to 68.5%) had high screen time, and 26.3% (95% CI, 23.8% to 28.9%) had both these behaviors. Characteristics associated with a higher probability of simultaneously having low active play and high screen time were older age, female gender, non-Hispanic black race/ethnicity, and having a BMI-for-age > or =95th percentile of the CDC growth reference.

CONCLUSION

Many young children in the US are reported to have physical activity and screen time behaviors that are inconsistent with recommendations for healthy pediatric development. Children who are overweight, approaching adolescence, girls, and non-Hispanic blacks may benefit most from public health policies and programs aimed at these behaviors.

A simple assessment of physical activity is associated with obesity and motor fitness in pre-school children

OBJECTIVE

Physical activity is an important determinant of energy balance. However, its impact on overweight/obesity has proved difficult to measure in pre-school children and few studies have found significant associations. A set of simple questions was used to distinguish pre-school children with high and low physical activity, and the association of this classification with childhood overweight/obesity and performance in an established motor test was investigated.

DESIGN

Survey, cross-sectional.

SETTING AND SUBJECTS

Weight and height were measured in 12,556 children taking part in the obligatory school entrance health examination 2004-5 and 2005-6 in three urban and three rural Bavarian regions. Their parents were asked to answer a questionnaire with a set of questions on physical activity.

RESULTS

The mean age of the children evaluated was 5.78 (sd 0.43) years, 6535 (52.1 %) were boys. Physically active children were less likely to be overweight (OR = 0.786, 95 % CI 0.687, 0.898) or obese (OR = 0.655, 95 % CI 0.506, 0.849) and achieved 6.7 (95 % CI 5.8, 7.7) % more jumps per 30 s than less active children in a motor test, adjusted for a number of potentially confounding variables.

CONCLUSIONS

Classification of pre-school children as physically active or not, based on a small set of questions, revealed significant associations with overweight/obesity and a motor test. Once further validated, this classification might provide a valuable tool to assess the impact of physical activity on the risk of childhood overweight and obesity.

A Review of the Relationship Between 100% Fruit Juice Consumption and Weight in Children and Adolescents

Studies assessing a relationship between consumption of 100% fruit juice by children and adolescents and weight are contradictory. The purpose of this review was to assess the 9 cross-sectional and 12 longitudinal studies that have looked at this association. Of the 9 cross-sectional studies reviewed, only 3 reported any association. Those studies used small, local convenience samples of preschool children; furthermore, selection criteria were not well defined. One found that preschool children consuming ≥ 12 fluid oz/day of 100% fruit juice had a higher prevalence of overweight than those who consumed less than 12 oz/day (32% vs 9%). Later, a separate study showed that this relationship held only for apple juice. Another study demonstrated an association of overweight and energy from juice. These 3 studies were not nationally representative. Only 3 of the longitudinal studies showed an association between 100% fruit juice consumption and weight; 1 found an association only in adolescent girls, and 2 reported an association in children who were already overweight. None of the longitudinal studies was nationally representative, but 5 had sample sizes of at least 1000, 2 were ethnically diverse, and 3 had geographically separate sites, suggesting that the findings could be applicable to wider populations. Based on the currently available evidence, it can be concluded that there is no systematic association between consumption of 100% fruit juice and overweight in children or adolescents. Data do support consumption of 100% fruit juice in moderate amounts and suggest that consumption of 100% fruit juice may be an important strategy to help children meet the current recommendations for fruit.

Relationships between the home environment and physical activity and dietary patterns of preschool children: a cross-sectional study

OBJECTIVE

To assess relationships between characteristics of the home environment and preschool children's physical activity and dietary patterns.

METHODS

Homes of 280 preschool children were visited and information obtained by direct observation and parent interview regarding physical and nutritional characteristics of the home environment. Children's physical activity, sedentary behaviour and dietary patterns were measured using standardised parent-report questionnaires. Associations were analysed using analysis of variance and correlation.

RESULTS

Parental physical activity (p = 0.03-0.008), size of backyard (p = 0.001) and amount of outdoor play equipment (p = 0.003) were associated with more outdoor play. Fewer rules about television viewing (p < 0.001) and presence of playstation (p = 0.02) were associated with more indoor sedentary time. Higher fruit and vegetable intake was associated with restricting children's access to fruit juice (p = 0.02) and restricting high fat/sugar snacks (p = 0.009). Lower intake of non-core foods was associated with restricting children's access to fruit juice (p = 0.007), cordial/carbonated drinks (p < 0.001) and high fat/sugar snacks (p = 0.003). Lower fruit and vegetable intake was associated with reminding child to 'eat up' (p = 0.007) and offering food rewards to eat main meal (p = 0.04). Higher intake of non-core foods was associated with giving food 'treats' (p = 0.03) and offering food rewards to eat main meal (p = 0.04). The availability of food groups in the home was associated with children's intake of these foods (fruit and vegetables, p < 0.001; fat in dairy, p = <0.001; sweetened beverages, p = 0.004-<0.001; non-core foods, p = 0.01-<0.001).

CONCLUSION

Physical attributes of the home environment and parental behaviours are associated with preschool children's physical activity, sedentary behaviour and dietary patterns. Many of these variables are modifiable and could be targeted in childhood obesity prevention and management.

Obesity prevention in child care: a review of U.S. state regulations

Objective

To describe and contrast individual state nutrition and physical activity regulations related to childhood obesity for child care centers and family child care homes in the United States.

Methods

We conducted a review of regulations for child care facilities for all 50 states and the District of Columbia. We examined state regulations and recorded key nutrition and physical activity items that may contribute to childhood obesity. Items included in this review were: 1) Water is freely available; 2) Sugar-sweetened beverages are limited; 3) Foods of low nutritional value are limited; 4) Children are not forced to eat; 5) Food is not used as a reward; 6) Support is provided for breastfeeding and provision of breast milk; 7) Screen time is limited; and 8) Physical activity is required daily.

Results

Considerable variation exists among state nutrition and physical activity regulations related to obesity. Tennessee had six of the eight regulations for child care centers, and Delaware, Georgia, Indiana, and Nevada had five of the eight regulations. Conversely, the District of Columbia, Idaho, Nebraska and Washington had none of the eight regulations. For family child care homes, Georgia and Nevada had five of the eight regulations; Arizona, Mississippi, North Carolina, Oregon, Tennessee, Texas, Vermont, and West Virginia had four of the eight regulations. California, the District of Columbia, Idaho, Iowa, Kansas, and Nebraska did not have any of the regulations related to obesity for family child care homes.

Conclusion

Many states lack specific nutrition and physical activity regulations related to childhood obesity for child care facilities. If widely implemented, enhancing state regulations could help address the obesity epidemic in young children in the United States.

Physical activity in preschoolers: understanding prevalence and measurement issues

Accurate physical activity quantification in preschoolers is essential to establish physical activity prevalence, dose-response relationships between activity and health outcomes, and intervention effectiveness. To date, best practice approaches for physical activity measurement in preschool-aged children have been relatively understudied. This article provides a review of physical activity measurement tools for preschoolers, an overview of measurement of preschoolers' physical activity, and directions for further research. Electronic and manual literature searches were used to identify 49 studies that measured young children's physical activity, and 32 studies that assessed the validity and/or reliability of physical activity measures with preschool-aged children. While no prevalence data exist, measurement studies indicate that preschool children exhibit low levels of vigorous activity and high levels of inactivity, boys are more active than girls, and activity patterns tend to be sporadic and omnidirectional. As such, measures capable of capturing differing activity intensities in very short timeframes and over multiple planes are likely to have the most utility with this population. Accelerometers are well suited for this purpose, and a number of models have been used to objectively quantify preschoolers' physical activity. Only one model of pedometer has been investigated for validity with preschool-aged children, showing equivocal results. Direct observation of physical activity can provide detailed contextual information on preschoolers' physical activity, but is subjective and impractical for understanding daily physical activity. Proxy-report questionnaires are unlikely to be useful for determining actual physical activity levels of young children, and instead may be useful for identifying potential correlates of activity. Establishing validity is challenging due to the absence of a precise physical activity measure, or 'criterion', for young children. Both energy expenditure (EE) and direct observation have been considered criterion measures in the literature; however, EE is influenced by multiple variables, so its use as a physical activity 'criterion' is not ideal. Also, direct observation is inherently subjective, and coding protocols may result in failure to capture intermittent activity, thereby limiting its utility as a physical activity criterion. Accordingly, these issues must be taken into account where EE or direct observation are used to validate physical activity instruments. A combination of objective monitoring and direct observation may provide the best standard for the assessment of physical activity measurement tools. Ideally, the convergent validity of various physical activity tools should be investigated to determine the level of agreement between currently available measures. The correlational approaches commonly employed in the assessment of physical activity measures do not reveal this relationship, and can conceal potential bias of either measure.