Association of television viewing with fasting and 2-h postchallenge plasma glucose levels in adults without diagnosed diabetes

OBJECTIVE—We examined the associations of television viewing time with fasting plasma glucose (FPG) and 2-h postchallenge plasma glucose (2-h PG) levels in Australian adults.

RESEARCH DESIGN AND METHODS—A total of 8,357 adults aged >35 years who were free from diagnosed diabetes and who attended a population-based cross-sectional study (Australian Diabetes, Obesity and Lifestyle Study [AusDiab]) were evaluated. Measures of FPG and 2-h PG were obtained from an oral glucose tolerance test. Self-reported television viewing time (in the previous week) was assessed using an interviewer-administered questionnaire. Homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and ß-cell function (HOMA-%B) were calculated based on fasting glucose and insulin concentrations.

RESULTS—After adjustment for confounders and physical activity time, time spent watching television in women was positively associated with 2-h PG, log fasting insulin, and log HOMA-%B and inversely associated with log HOMA-%S (P < 0.05) but not with FPG. No significant associations were observed with glycemic measures in men. The ß-coefficients across categories of average hours spent watching television per day (<1.0, 1.0–1.9, 2.0–2.9, 3.0–3.9, and ≥4.0) for 2-h PG in women were 0 (reference), 0.009, 0.047, 0.473, and 0.501, respectively (P for trend = 0.02).

CONCLUSIONS—Our findings highlight the unique deleterious relationship of sedentary behavior (indicated by television viewing time) and glycemic measures independent of physical activity time and adiposity status. These relationships differed according to sex and type of glucose measurement, with the 2-h PG measure being more strongly associated with television viewing. The findings suggest an important role for reducing sedentary behavior in the prevention of type 2 diabetes and cardiovascular disease, especially in women.

Association between the family environment and television viewing in Australian children

Aim: To describe the time children spend watching television (TV) and to assess associations between TV viewing time, the family environment and weight status.

Methods: Parents reported the amount of time children watched TV/video both for ‘the previous school day’ and ‘usually’ and described aspects of the family environment influencing TV access as part of a large cross-sectional study in the Barwon South-western region of Victoria, Australia. Child weight status was  based on measured height and weight. All data were collected in 2003/2004.

Results: A total of 1926 children aged 4–12 years participated. Parent-reported mean ± SE TV time for the previous school day was 83 ± 1.5 min. Children who lived in a family with tight rules governing TV viewing time (22%), or who never watched TV during dinner (33%), or had only one TV in the household (23%) or had no TV in their bedroom (81%) had significantly less TV time than their  counterparts. Overweight or obese children had more TV time than healthy weight children 88 ± 2.9 versus 82 ± 1.7 min per day (P = 0.04). They were also more likely to live in a household where children had a TV in their bedroom than healthy weight children (25% vs. 17%, P < 0.001).

Conclusion: Strategies to reduce TV time should be included as part of broader strategies to prevent childhood obesity. They should include messages to parents about not having a TV in children’s bedrooms, encouraging family rules restricting TV viewing, and not having the TV on during dinner.

Family and home correlates of television viewing in 12-13 year old adolescents: the Nepean study

Background
Few young people meet television viewing guidelines.
Purpose
To determine the association between factors in the family and home environment and watching television, including videos and DVDs, in early adolescence.
Methods
Cross-sectional, self-report survey of 343 adolescents aged 12–13 years (173 girls), and their parents (338 mothers, 293 fathers). Main measures were factors in the family and home environment potentially associated with adolescents spending ≥ 2 hours per day in front of the television. Factors examined included family structure, opportunities to watch television/video/DVDs, perceptions of rules and regulations on television viewing, and television viewing practices.
Results
Two-thirds of adolescents watched ≥ 2 hours television per day. Factors in the family and home environment associated with adolescents watching television ≥ 2 hours per day include adolescents who have siblings (Adjusted Odds Ratio [95%CI] AOR = 3.0 [1.2, 7.8]); access to pay television (AOR = 2.0 [1.1, 3.7]); ate snacks while watching television (AOR = 3.1 [1.8, 5.4]); co-viewed television with parents (AOR = 2.3 [1.3, 4.2]); and had mothers who watched ≥ 2 hours television per day (AOR = 2.4 [1.3, 4.6]).
Conclusion
There are factors in the family and home environment that influence the volume of television viewed by 12–13 year olds. Television plays a central role in the family environment, potentially providing a means of recreation among families of young adolescents for little cost. Interventions which target family television viewing practices and those of parents, in particular, are more likely to be effective than interventions which directly target adolescent viewing times.

Television, computer use and body mass index in Australian primary school children

Objective: To investigate relationships between children's body mass index (BMI) and parent reports of children's television and video game/computer habits, controlling for other potential risk factors for paediatric obesity.

Methods: Child BMI was calculated from measured height and weight collected in 1997 as part of a large, representative, cross-sectional study of children in Victoria, Australia. Parents reported the amount of time children watched television and used video games/computers, children's eating and activity habits, parental BMI and sociodemographic details.

Results: A total of 2862 children aged 5−13 years participated. Child mean BMI z-score was significantly related to television (F = 10.2₃, P < 0.001) but not video game/computer time (F = 2.2₃, P = 0.09), but accounted for only 1 and 0.2% of total BMI variance, respectively. When parental BMI, parental education, number of siblings, food intake, organized exercise and general activity level were included, television ceased to be independently significantly related to child BMI. Using adjusted logistic regression, the odds of being overweight and obese generally increased with increasing television viewing. No relationship was found for video game/computer use.
Conclusions: A small proportion of variance in child BMI was related to television, but not video game/computer time. This was far outweighed by the influence of other variables. Causal pathways are likely to be complex and interrelated.

Parental awareness and attitudes about food advertising to children on Australian television

Objective: To assess parents' concern regarding television food advertising to children and the marketing methods used, their awareness of existing regulations and support for strengthening restrictions, and to determine whether these factors differ across sociodemographic groups.

Methods: A randomly selected sample of 400 parents of children under 14 years in all Australian States and Territories completed the cross-sectional telephone survey in March 2007. Data were weighted by metropolitan and regional population proportions.

Results: Parents were concerned about unhealthy food advertising to children (67.3%), use of popular personalities (67.7%), toys (76.4%), and advertising volume (79.7%). Older parents, of high socioeconomic status (SES), with fewer household televisions were more likely to be concerned. Only 47.4% of parents were aware of current regulations and those with a tertiary education were more likely to be aware: odds ratio (OR) 2.96 (95% CI: 1.55-5.65). Parents supported a change from self-regulation (92.8%), a ban on unhealthy food advertising to children (86.8%) and, to a lesser extent, a ban on all food advertising (37.3%).

Conclusions and implications: There was widespread parental concern about food advertising and strong support for tighter restrictions. Given that the existing regulations rely on complaints and awareness is low, particularly among parents with lower education levels, a system of external monitoring and enforcement is essential. Clearly more effective regulations are needed to protect children and parental support for this is high.

Television time and continuous metabolic risk in physically active adults

Purpose: Among Australian adults who met the public health guideline for the minimum health-enhancing levels of physical activity, we examined the dose-response associations of television-viewing time with continuous metabolic risk variables.

Methods: Data were analyzed on 2031 men and 2033 women aged >= 25 yr from the 1999-2000 Australian Diabetes, Obesity and Lifestyle study without clinically diagnosed diabetes or heart disease, who reported at least 2.5 h·wk-1 of moderate- to vigorous-intensity physical activity. Waist circumference, resting blood pressure, and fasting and 2-h plasma glucose, triglycerides, and high-density-lipoprotein cholesterol (HDL-C) were measured. The cross-sectional associations of these metabolic variables with quartiles and hours per day of self-reported television-viewing time were examined separately for men and for women. Analyses were adjusted for age, education, income, smoking, diet quality, alcohol intake, parental history of diabetes, and total physical activity time, as well as menopausal status and current use of postmenopausal hormones for women.

Results: Significant, detrimental dose-response associations of television-viewing time were observed with waist circumference, systolic blood pressure, and 2-h plasma glucose in men and women, and with fasting plasma glucose, triglycerides, and HDL-C in women. The associations were stronger in women than in men, with significant gender interactions observed for triglycerides and HDL-C. Though waist circumference attenuated the associations, they remained statistically significant for 2-h plasma glucose in men and women, and for triglycerides and HDL-C in women.

Conclusions: In a population of healthy Australian adults who met the public health guideline for physical activity, television-viewing time was positively associated with a number of metabolic risk variables. These findings support the case for a concurrent sedentary behavior and health guideline for adults, which is in addition to the public health guideline on physical activity.

Is television viewing time a marker of a broader pattern of sedentary behavior?

Background: Television (TV) viewing time is associated with abnormal glucose metabolism, the metabolic syndrome, and risk of type 2 diabetes; associations are stronger and more consistent in women. One explanation of this difference may be that TV viewing is a marker of an overall pattern of sedentary behavior in women.

Purpose: We sought to examine associations of TV viewing time with other sedentary behaviors and with leisure-time physical activity in a large sample of Australian adults.

Methods: Adults aged between 20 and 65 years (n=2,046) completed a  self-administered questionnaire on TV viewing, five other leisure-time sedentary behaviors, and leisure-time physical activity. Mean adjusted time spent in other sedentary behaviors and in physical activity was compared across TV-time  categories previously shown to be associated with abnormal glucose  metabolism.

Results: After adjustment for body mass index and sociodemographic variables, women’s time spent watching TV was associated positively with time in other sedentary behaviors and negatively with leisure-time physical activity, but no such associations were observed in men.

Conclusions: TV viewing time may be a robust marker of a sedentary lifestyle in women but not in men. Gender differences in the pattern of sedentary behaviors may explain at least in part the gender differences in the previously reported associations of TV viewing time with biological attributes related to type 2   diabetes.

Television viewing and abdominal obesity in young adults : is the association mediated by food and beverage consumption during viewing time or reduced leisure-time physical activity?

BACKGROUND:The behavioral pathways through which television (TV) viewing leads to increased adiposity in adults are unclear.

OBJECTIVE:We wanted to determine whether the association between TV viewing and abdominal obesity in young adults is mediated by food and beverage consumption during TV viewing time or by a reduction in overall leisure-time physical activity (LTPA).

DESIGN:This study involved a cross-sectional analysis of data from 2001 Australian adults aged 26–36 y. Waist circumference (WC) was measured at study clinics, and TV viewing time, frequency of food and beverage consumption during TV viewing, LTPA, and demographic characteristics were self-reported.

RESULTS:Women watching TV >3 h/d had a higher prevalence of severe abdominal obesity (WC: =88 cm) compared with women watching =1 h/d [prevalence ratio (PR): 1.89; 95% CI: 1.32, 2.71]. Moderate abdominal obesity (WC: 94–101.9 cm) was more prevalent in men watching TV >3 h/d than in men watching =1 h/d (PR: 2.16; 95% CI: 1.37, 3.41). Adjustment for LTPA made little difference, but adjustment for food and beverage consumption during TV viewing attenuated the associations (PR: 1.48; 95% CI: 1.01, 2.17 for women; PR: 1.73; 95% CI: 1.06, 2.83 for men).

CONCLUSIONS:The association between TV viewing and WC in young adults may be partially explained by food and beverage consumption during TV viewing but was not explained by a reduction in overall LTPA. Other behaviors likely contribute to the association between TV viewing and obesity.

Television viewing habits and time use in Australian preschool children : an exploratory study

The overall aim in this study was to investigate time use in Australian preschool children, paying close attention to the types of television programs and videos/DVDs they watch. Ninety-two mothers of preschool children completed five activity diaries, for three typical weekdays and two weekend days. On average, children spent around just over 1 hour per weekday watching television and 30 minutes watching videos/DVDs; on weekends they spent on average 1 hour watching television and the same amount of time watching videos/DVDs. On weekdays, children spent more time watching child informative television; on the weekend they spent more time watching child animated television programs. When not watching television, children were mainly engaged in general play or in outdoor play. Child informative television was associated positively with time spent outdoors and in general and pretend play on weekdays (and for general play also on weekend days), whereas overall television viewing was correlated negatively with reading. Our findings suggest that the content of television programs may play a critical role in the relationship between television and other daily activities.

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.