Measurement of television viewing in children and adolescents: a systematic review

Excessive TV viewing and cardiovascular disease risk factors in adolescents. The AVENA cross-sectional study

Background

Excessive television (TV) viewing might play an important role in the development of cardiovascular disease (CVD). The aim of this study was to examine the independent associations between TV viewing and CVD risk factors in adolescents.

Methods

A sample of 425 adolescents, aged 13- to 18.5-year-old, was included in this study. Body mass index (BMI), waist circumference (WC), glucose, total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein (apo) A-1, apo B-100, and lipoprotein(a) levels were determined. A composite CVD risk score was computed based on age-, sex-, sexual maturation- and race-standardized triglycerides, HDL-cholesterol, LDL-cholesterol and glucose. TV viewing was self-reported.

Results

Two hundred and twenty-five adolescents (53%) who spent >3 hrs/day watching TV were considered as the "high TV viewing" group. Ninety-nine adolescents (23%) from the total sample were classified as overweight according to International age- and sex-specific BMI values. The high TV viewing group had significantly less favorable values of HDL-cholesterol, glucose, apo A1 and CVD score, independent of age, sex, sexual maturation, race and weight status. There was a significant interaction effect of TV viewing × weight status (P = 0.002) on WC, and the negative influence of TV viewing on WC persisted in the overweight group (P = 0.031) but was attenuated in non-overweight adolescents (P > 0.05).

Conclusion

Excessive TV viewing seems to be related to an unfavorable CVD risk factors profile in adolescence. Reducing TV viewing in overweight adolescents might be beneficial to decrease abdominal body fat.

Sedentary behavior and sleep: paradoxical effects in association with childhood obesity

Sedentary behavior and sleep may be working in concert to increase the likelihood of a child becoming overweight, but in paradoxical ways. Reduction of sedentary behavior (that is, media screen time) has been extensively researched and touted as an intervention target. Inadequate sleep as a putative risk factor for obesity is only beginning to be explored. In this paper, we review the current state of research regarding these factors, and describe the existing evidence and mechanisms proposed to explain these relationships. Whereas the association between weight and sedentary behavior has been consistently shown in observational studies, effect sizes are small, and multiple mechanisms appear to be operating. Recent cross-sectional and longitudinal evidence suggests a link between short sleep duration and weight. Possible mechanisms here include direct metabolic effects as well as indirect behavioral pathways, including the presence of electronic media in children's bedrooms. Measurement issues present a challenge to both areas of research. Prospective studies that include more accurate measures of both sedentary behavior and of sleep will be needed to clarify causal pathways.

Parent and child physical activity and sedentary time: do active parents foster active children?

Background

Physical activity has many positive effects on children's health while TV viewing has been associated with adverse health outcomes. Many children do not meet physical activity recommendations and exceed TV viewing guidelines. Parents are likely to be an important influence on their children's behaviour. There is an absence of information about the associations between parents' and children's physical activity and TV viewing.

Methods

Year 6 children and their parent were recruited from 40 primary schools. Results are presented for the 340 parent-child dyads with accelerometer data that met a ≥ 3 day inclusion criteria and the 431 parent-child dyads with complete self-reported TV viewing. Over 80% of the dyads with valid TV viewing data included mothers and their child. Mean minutes of moderate to vigorous physical activity (MVPA), minutes of sedentary time per day and counts per minute were assessed by accelerometer. Self-reported hours of TV viewing were coded into 3 groups (< 2 hours per day, 2-4 hours per day and >4 hours per day. Linear and multi-nominal regression models were run by child gender to examine parent-child associations.

Results

In linear regression models there was an association for the overall sedentary time of girls and their parents (t = 2.04. p = .020) but there was no association between girls' and parents' physical activity. There were no associations between parents' and boys' sedentary or physical activity time. For girls, the risk of watching more than 4 hours of TV per day, (reference = 2 hours of TV per day), was 3.67 times higher if the girl's parent watched 2-4 hours of TV per day (p = 0.037). For boys, the risk of watching more than 4 hours of TV per day, was 10.47 times higher if the boy's parent watched more than 4 hours of TV per day (p = 0.038).

Conclusions

There are associations in the sedentary time of parents and daughters. Higher parental TV viewing was associated with an increased risk of high levels of TV viewing for both boys and girls. There were no associations between the time that parents and children spend engaged in physical activity.

Food patterns according to sociodemographics, physical activity, sleeping and obesity in Portuguese children

Our study aimed to describe the association between food patterns and gender, parental education, physical activity, sleeping and obesity in 1976 children aged 5−10 years old. Dietary intake was measured by a semi quantitative food frequency questionnaire; body mass index was calculated and categorized according to the IOTF classification. Factor analysis and generalized linear models were applied to identify food patterns and their associations. TV viewing and male gender were significant positive predictors for fast-food, sugar sweetened beverages and pastry pattern, while a higher level of maternal education and longer sleeping duration were positively associated with a dietary patterns that included fruit and vegetables.

Profiles of sedentary behavior in children and adolescents: the US National Health and Nutrition Examination Survey, 2001-2006

OBJECTIVE

To describe the prevalence of time spent in sedentary behaviors (e.g., TV/video and computer use) among youth in the US.

METHODS

The National Health and Nutrition Examination Survey (2001-06) provided data to examine sedentary behavior across age groups (2-5, 6-11, and 12-15 years of age), ethnic groups (European [EA], African [AA], and Mexican American [MA]), and body mass index (BMI) categories (normal weight, overweight, obese).

RESULTS

The sample included 8 707 (50.7% boys) children aged 2 to 15 years. Seventy percent of the sample was normal weight, 18.1% was overweight, and 11.5% was obese. The total proportion of young people engaged in TV/video viewing, computer use, and total screen time > or = 2 hours daily was 33.0%, 6.7%, and 47.3%, respectively. More boys (49.4%) than girls (45.0%); older (12-15 years: 56.0%) versus younger children (2-5 years: 35.3% and 6-11 years: 49.1%); AA (66.1%) versus EA (42.5%) and MA (46.1%); obese (58.5%) versus overweight (50.8%) versus normal weight (44.6%); and low and middle income (<$25 K: 51.4% and $25-45 K: 51.2%) versus high income (>$45 K: 42.6%) children spent > or = 2 hours daily in screen time.

CONCLUSION

Nearly half (47%) of US children exceed > or = 2 hours/day of time in sedentary behavior. Further, it appears there are gender, age, ethnic, BMI-defined weight status, and income differences in exceeding > or = 2 hours/day in sedentary behavior. These results will be useful in planning targeted interventions at those populations with a higher prevalence of sedentary behavior.

Validity and reliability of measures of television viewing time and other non-occupational sedentary behaviour of adults: a review

Time spent in non-occupational sedentary behaviours (particularly television viewing time) is associated with excess adiposity and an increased risk of metabolic disorders among adults; however, there are no reviews of the validity and reliability of assessing these behaviours. This paper aims to document measures used to assess adults' time spent in leisure-time sedentary behaviours and to review the evidence on their reliability and validity. Medline, CINAHL and Psych INFO databases and reference lists from published papers were searched to identify studies in which leisure-time sedentary behaviours had been measured in adults. Sixty papers reporting measurement of at least one type of leisure-time sedentary behaviour were identified. Television viewing time was the most commonly measured sedentary behaviour. The main method of data collection was by questionnaire. Nine studies examined reliability and three examined validity for the questionnaire method of data collection. Test-retest reliabilities were predominantly moderate to high, but the validity studies reported large differences in correlations of self-completion questionnaire data with the various referent measures used. To strengthen future epidemiological and health behaviour studies, the development of reliable and valid self-report instruments that cover the full range of leisure-time sedentary behaviour is a priority.

Work pattern causes bias in self-reported activity duration: a randomised study of mechanisms and implications for exposure assessment and epidemiology

BACKGROUND

Self-reported activity duration is used to estimate cumulative exposures in epidemiological research.

OBJECTIVE

The effects of work pattern, self-reported task dullness (a measure of cognitive task demand), and heart rate ratio and perceived physical exertion (measures of physical task demands) on error in task duration estimation were investigated.

METHODS

24 participants (23-54 years old, 12 males) were randomly assigned to execute three tasks in either a continuous (three periods of 40 continuous minutes, one for each task) or a discontinuous work pattern (40 min tasks each divided into four periods of 4, 8, 12 and 16 min). Heart rate was measured during tasks. After completing the 2 h work session, subjects reported the perceived duration, dullness and physical exertion for each of the three tasks. Multivariate models were fitted to analyse errors and their absolute value to assess the accuracy in task duration estimation and the mediating role of task demands on the observed results.

RESULTS

Participants overestimated the time spent shelving boxes (up to 38%) and filing journals (up to 9%), and underestimated the time typing articles (up to -22%). Over- and underestimates and absolute errors were greater in the discontinuous work pattern group. Only the self-reported task dullness mediated the differences in task duration estimation accuracy between work patterns.

CONCLUSIONS

Task-related factors can affect self-reported activity duration. Exposure assessment strategies requiring workers to allocate work time to different tasks could result in biased measures of association depending on the demands of the tasks during which the exposure of interest occurs.

Television, physical activity, diet, and body weight status: the ARIC cohort

Background

Television (TV) watching is the most common leisure activity in the United States. Few studies of adults have described the relationship between TV and health behaviors such as physical activity, diet, and body weight status.

Methods

Extant data from the Atherosclerosis Risk in Communities (ARIC) Study were analyzed to assess the association of TV with physical activity, diet, and body mass index (BMI) among 15,574 adults at baseline (1986–89) and 12,678 adults six years later. Television, physical activity, and diet were collected with questionnaires and BMI was measured at both time points. Based on baseline TV exposure, adults were categorized into high, medium, and low TV exposure. Linear and logistic regression models were adjusted for gender, age, race-center, smoking, education, and general health.

Results

Relative to participants who had low TV exposure, those with high TV exposure were more likely to be less physically active and have a poorer dietary profile at baseline and six-years later. Participants with high TV exposure at baseline had a 40% and 31% greater odds of being considered insufficiently active at baseline (1.40, 95% CI 1.26, 1.55), and six years later (1.31, 95% CI 1.18, 1.46). At baseline, high TV exposure was also associated with a 20% to 30% greater odds of being above the median for servings of salty snacks (1.37, 95% CI 1.24, 1.51), sweets (1.26, 95% CI 1.15, 1.38), and sweetened drinks (1.29, 95% CI 1.17, 1.42), and below the median for fruit and vegetable servings (1.36, 95% CI 1.24, 1.50). Higher TV exposure was also cross-sectionally associated with a greater odds for being overweight or obese (1.43, 95% CI 1.29, 1.58). Similar associations were observed between baseline TV exposure and six-year physical activity and diet, but were not observed with BMI after six years follow-up.

Conclusion

These results support the hypothesis that time spent watching TV is associated with deleterious effects on physical activity, diet, and BMI.

The Parent Mealtime Action Scale (PMAS). Development and association with children's diet and weight

A new and comprehensive Parent Mealtime Action Scale (PMAS) was developed to identify dimensions of mealtime behaviors used by parents, then examined for its usefulness to explain variance in children's diet and weight status. Exploratory factor analysis with 2008 mothers and two confirmatory factor analyses with 541 mothers and 439 fathers produced a 31-item scale with nine dimensions. Mothers reported more gentle PMAS actions like setting SNACK LIMITS, ensuring DAILY FV AVAILABILITY, and using FAT REDUCTION and POSITIVE PERSUASION during meals, whereas fathers reported more forceful PMAS actions like INSISTENCE ON EATING. Seven PMAS dimensions explained variance in children's diet and weight status even when in competition with three well-known predictors (genetic risk, exercise, television). Children with healthier diets and weight had parents who often ensured DAILY FV AVAILABILITY and used FAT REDUCTION, POSITIVE PERSUASION, and INSISTENCE ON EATING during meals, but who rarely showed SNACK MODELING, allowed children too MANY FOOD CHOICES, or made them SPECIAL MEALS different from the shared family meal. Parents also may respond to children's overweight by using more FAT REDUCTION. The PMAS offers a new research, clinical, and educational tool to guide parents in actions most associated with children's diet and weight status.

Screen-viewing and the home TV environment: the European Youth Heart Study

OBJECTIVE

Examine if home environmental factors are associated with screen-viewing.

METHODS

Data are for 2670, 3rd and 9th grade participants in Denmark, Portugal, Estonia and Norway collected between 1997 and 2000. Outcomes were spending >2 h after-school watching television (TV) and >1 h per day playing computer games. Child Autonomy and the home TV Environment were exposures.

RESULTS

Each unit increase in Child Autonomy was associated with 9% increase in risk of watching more than 2 h of TV per day after school and a 19% increase in risk of spending more than an hour per day playing computer games. TV Environment was associated with a 31% per unit increase in risk of watching >2 h of TV after school and 11% increase in risk of spending >1 h playing computer games.

CONCLUSIONS

A family environment in which after-school TV viewing is part of the home culture and homes where children have more autonomy over their own behavior are associated with an increased risk of watching >2 h of TV per day after school and spending more >1 h per day playing computer games. The home screen-viewing environment and Child Autonomy may be malleable targets for changing screen-viewing.

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.

Maternal depressive symptoms and physical activity in very low-income children

OBJECTIVE

To test the contribution of maternal depression during late infancy to physical activity in children 5 years later.

METHOD

Children (n = 168) from very low-income households in semiurban Mexico were assessed as toddlers (15 months, Time 1) and at pre-school age (4-6 years, Time 2). Child low activity level (<20 minutes of activity daily for <7 d/wk) at Time 2 was the primary outcome measure and maternal depressive symptoms (Center for Epidemiologic Studies-Depression Scale) by self-report at Time 1 was the primary independent variable. Covariates tested included child age, sex, BMI percentile, television viewing and behavior (Behavior Problem Index subscales), current maternal depressive symptoms, age, BMI and physical activity level, and family socioeconomic status; all covariates were assessed at Time 2 except for socioeconomic status.

RESULTS

At 4 to 6 years old, 27.5% of children were categorized with low activity level. Exposure to high maternal depressive symptoms at child age 15 months was associated with an increased risk of having a low activity level at age 4 to 6 years (OR, 2.38; 95% CI, 1.05-5.40); results were unchanged with the inclusion of current maternal depressive symptoms. High child TV viewing was significantly associated with low activity level (OR, 5.44; 95% CI, 2.06-14.3), but did not change the effect of maternal depressive symptoms in early childhood. Tests of mediation revealed that current child internalizing behavior, but not externalizing behavior, significantly attenuated the association between early high maternal depressive symptoms and later childhood activity level.

CONCLUSION

Exposure to maternal depressive symptoms in late infancy is a risk factor for low activity level in later childhood and the association may be mediated by child internalizing factors.

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.

Association between regular participation in sports and leisure time behaviors in Brazilian adolescents: a cross-sectional study

Background

The belief that adolescents engaged in sports increase their overall physical activity level while simultaneously decreasing physical inactivity has been the foundation of many intervention programs in developing countries. The aim of this study was to analyze the association between regular participation in sports and both active behaviors and TV viewing during leisure time.

Methods

A total of 1752 Brazilian adolescents (812 = male and 940 = female) participated in this study. Regular participation in sports, as well as active behaviors (exemplified by walking or cycling) and TV viewing during leisure time were assessed by means of a questionnaire. The chi-square test analyzed the association between sports practice and leisure time behaviors, and the Poisson regression with robust variance indicated the magnitude of these associations.

Results

The prevalence of regular participation in sports was 14.8% (95% confidence interval 13.2% to 16.5%). After adjustment for all confounders, participation in sports was associated with, at the highest frequency, cycling (PR = 2.55 [1.80–3.60]) and walking (PR = 2.69 [1.98–3.64]) during leisure time. However, there was not an association between the participation in sports and frequency of TV viewing (PR = 1.28 [0.81–2.02]).

Conclusion

This study presented data indicating that the regular participation in sports is positively associated with a higher frequency of physically active behaviors during leisure time. However, the results did not support the hypothesis that the engagement in sports necessarily decreases leisure time spent in TV viewing.

Middle-school children's understanding of physical activity: "if you're moving, you're doing physical activity"

This qualitative descriptive study explored the understanding of physical activity from the perspectives of middle-school children (n = 12; ages 11-15 years) who participated in 15 collaborative exploratory meetings (approximately 1.5 hours/meeting) that were audiorecorded. Content analysis was completed; a pediatric nurse specialist and the participating children validated the findings. The children understood physical activity concretely, considering everything they did as physical activity based on their primary criterion of body movement. The children adeptly recalled activities and activity time duration, but struggled with categorizing the intensity of their activities. Domains of activity included home and school; social activities crossed both arenas. The study contributes to our knowledge of children's understanding of physical activity, highlighting the concreteness of the children's thinking, including their perspectives on evidence and conclusions based on their notions of evidence. Implications for nursing are discussed.

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

Background

There 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.

Methods

We 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 child's weight status or adiposity.

Results

Watching > 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)

Conclusion

Watching > 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 children's media use. Computer use was also related to higher adiposity in preschool children, but not weight status. Intervention studies to limit preschool children's media use are warranted.