Household obesity prevention: Take Action--a group-randomized trial

The purpose of the present study was to evaluate an intervention to prevent weight gain among households (HHs) in the community. Ninety HHs were randomized to intervention or control group for 1 year. Intervention consisted of six face-to-face group sessions, placement of a television (TV) locking device on all home TVs, and home-based intervention activities. Measures were collected in person at baseline and 1 year. Weight, height, eating behaviors, physical activity (PA), and TV viewing were measured among HH members ages ≥ 12 years. Follow-up rate at 1 year was 96%. No significant intervention effects were observed for change in HH BMI-z score. Intervention HHs significantly reduced TV viewing, snacks/sweets intake, and dollars per person spent eating out, and increased (adults only) PA and self-weighing frequency compared with control HHs. A 1 year obesity prevention intervention targeting entire HHs was effective in reducing TV viewing, snack/sweets intake and eating out purchases. Innovative methods are needed to strengthen the home food environment intervention component. Longer intervention durations also need to be evaluated.     

Identifying patterns of eating and physical activity in children: a latent class analysis of obesity risk

We used latent class analysis (LCA) to identify heterogeneous subgroups with respect to behavioral obesity risk factors in a sample of 4th grade children (n = 997) residing in Southern California. Multiple dimensions assessing physical activity, eating and sedentary behavior, and weight perceptions were explored. A set of 11 latent class indicators were used in the analysis. The final model yielded a five-class solution: "High-sedentary, high-fat/high-sugar (HF/HS) snacks, not weight conscious," "dieting without exercise, weight conscious," "high-sedentary, HF/HS snacks, weight conscious," "active, healthy eating," and "low healthy, snack food, inactive, not weight conscious." The results suggested distinct subtypes of children with respect to obesity-related risk behaviors. Ethnicity, gender, and a socioeconomic status proxy variable significantly predicted the above latent classes. Overweight or obese weight status was determined based on the Centers for Disease Control and Prevention BMI (kg/m2)-for-age-and-sex percentile (overweight, 85th percentile ≤ BMI < 95th percentile; obese, 95th percentile ≤ BMI). The identified latent subgroup membership, in turn, was associated with the children's weight categories. The results suggest that intervention programs could be refined or targeted based on children's characteristics to promote effective pediatric obesity interventions.     

Associations of obesogenic behaviors in mothers and obese children participating in a randomized trial

Relatively little research has assessed the association between obesogenic behaviors in parents and their children. The objective of the present analysis was to examine cross-sectional associations in television (TV)/video viewing, sugar-sweetened beverage intake, and fast food intake between mothers and their preschool aged children. We studied baseline data among 428 participants in High Five for Kids, a randomized controlled trial of behavior change among overweight and obese children of ages 2-6.9 years. The main exposures were whether mothers viewed TV/videos <1 h/day, drank <1 serving/day of sugar-sweetened beverages, and ate fast food <1 time/week. The main outcomes were whether children met these goals for the same behaviors. Using multivariate logistic regression adjusted for maternal and child characteristics, we estimated odds ratios of children meeting the behavioral goals. The majority of mothers ate fast food <1 time/week (73%) and drank <1 serving/day of sugar-sweetened beverages (73%), while few mothers viewed <1 h/day of TV/videos (31%). Most children met the fast food goal (68%), but not the goals for sugar-sweetened beverages (31%) or TV/video viewing (13%). In adjusted models, the odds ratios for a child meeting the goal were 3.2 (95% confidence interval (CI) 1.7, 6.2) for TV/video viewing, 5.8 (95% CI 2.8, 12.0) for sugar-sweetened beverage intake, and 17.5 (95% CI 9.8, 31.2) for fast food intake if their mothers met the goal for the same behavior. Obesogenic behaviors of mothers and preschool aged children were strongly associated. Our findings lend support to obesity prevention strategies that target parental behavior and the family environment.     

Television viewing and obesity in 300 women: evaluation of the pathways of energy intake and physical activity

We assessed the roles of energy intake and physical activity in the relationships among television (TV) viewing, body composition, and obesity using high-quality measurement methods. Adult women (n = 300) reported TV viewing behavior, which was categorized into infrequent (≤ 1 h/day), moderate (2 h/day), and frequent (≥ 3 h/day) viewing. Body fat percentage (BF%) was assessed using plethysmography (Bod Pod) and BMI was calculated from height and body weight. Energy intake and physical activity, including time spent in sedentary, moderate, and vigorous physical activity (PA), were objectively measured using 7-day weighed food records and 7-day accelerometry, respectively. The mean BF% of frequent TV viewers (34.6 ± 6.9%) was significantly greater (F = 3.9, P = 0.0218) than those of moderate (31.5 ± 6.7%) and infrequent viewers (30.8 ± 7.0%); however, BMI did not differ across the TV viewing groups (F = 0.8, P = 0.4172). Controlling statistically for differences in age, education, time in sedentary activity, time in moderate activity, and energy intake, considered individually, had no influence on the relationships between TV viewing and BF%, nor TV and BMI. Moreover, the relationship between TV and BF% remained significant after adjusting for differences in BMI (F = 3.6, P = 0.0276). However, adjusting for total PA reduced the relationship between TV and BF% to nonsignificance (F = 2.5, P = 0.0810), as did time spent in vigorous PA (F = 2.2, P = 0.1307). These data suggest a strong relationship between TV viewing and BF%. This association appears to be due, in part, to differences in total PA, particularly vigorous PA, but not time spent in sedentary activity, moderate activity, or energy intake.     

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 ≥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.     

Television Viewing Is Not Predictive of BMI in Black and Hispanic Young Adult Females

Previous studies have observed that television (TV) viewing is predictive of obesity and weight gain. We examined whether the cross‐sectional association between TV viewing and BMI varied by racial/ethnic subgroups among young women in Wave III (collected in 2001–2002) of the National Longitudinal Study of Adolescent Health. We used multivariate linear regression to examine the relationship between TV viewing and BMI among 6,049 females while controlling for sociodemographic and health attributes. We stratified the sample by race/ethnicity to better understand the association between TV viewing and BMI across different groups. Black and Hispanic females had higher BMIs (black: 28.5 kg/m², Hispanic: 27.3 kg/m², white: 26.0 kg/m²) than white females, while black females reported higher numbers of hours spent watching TV (black: 14.7 h/week, Hispanic: 10.6 h/week, white: 11.2 h/week) when compared to their white and Hispanic peers. TV viewing was positively associated with BMI (β = 0.79, P = 0.003 for 8–14 vs. ≤7 h/week; β = 1.18, P = 0.01 for >14 vs. ≤7 h/week) independent of race/ethnicity, age, maternal education, history of pregnancy, parental obesity, and household income. However, in models stratified by race/ethnicity, increased TV viewing was associated with increased BMI only among white females; TV viewing was not predictive of higher BMI in black or Hispanic young adult females. Among black and Hispanic females, counseling to decrease TV viewing may be important but insufficient for promoting weight loss.     

Association of Family Environment with Children's Television Viewing and with Low Level of Physical Activity

Objective: This study examined associations between the family environment and children's television (TV) viewing and likelihood of being low‐active. Research Methods and Procedures: In 2001, children were recruited from 19 primary schools in Melbourne, Australia. Parents completed a questionnaire about their child's TV viewing and the family environment. Children also completed a questionnaire and wore an accelerometer for 8 days. Movement counts were used to identify low‐active children (lowest quartile). Data were analyzed in May 2004. Results: The sample consisted of 878 children (mean age = 11.5 ± 0.6 yrs). Multiple logistic regression revealed that socioeconomic status [adjusted odds ratios (AOR) = 0.4 boys], frequency families watched TV together (AOR = 2.0 boys), mothers’ (AOR = 1.8 boys; AOR = 2.5 girls) and fathers’ (AOR = 2.6 boys; AOR = 2.8 girls) TV viewing, and rules prohibiting TV during mealtimes (AOR = 0.6 boys; AOR = 0.6 girls) related to children watching TV ≥2 h/d. Variables associated with low‐level physical activity included self‐reported enjoyment of Internet use (AOR = 1.7 boys) and preference for watching TV (AOR = 2.3 girls), perception that mother uses computer a lot (AOR = 1.9 boys) and likes using the computer (AOR = 0.6 girls), fathers’ reported computer/electronic games use (AOR = 1.7 girls), frequency families used computer together (AOR = 0.4 girls), rules that TV viewing must be supervised (AOR = 1.9 boys; AOR = 0.6 girls), and having pay TV (AOR = 0.6 boys) and electronic games at home (AOR = 2.6 boys). Discussion: These findings suggest that the relationships between the family environment and TV viewing and low‐level activity are complex and that these behaviors are distinct.     

Age-dependent association of exposure to television screen with children's urinary melatonin excretion?

OBJECTIVES: Changes in magnetic field are associated with a decrease in nocturnal urinary melatonin excretion. Television screens emit low and very low frequency electromagnetic waves (radiofrequencies and light) and exposure to them may be associated with a decrease in 24-hour melatonin in children's urine. Design and setting. An observational study in schools of Cavriglia, Italy, determined melatonin in 24-hour urines from 42 boys and 32 girls 6 to 13 years of age after one week of watching TV and after another week of abstaining from watching TV. RESULTS AND MAIN FINDINGS: In a gender- and age-dependent fashion, exposure to a television screen was associated with lower urinary melatonin concentrations, affecting particularly younger children at a pubertal stage when important changes in melatonin's time structure occur. CONCLUSION: Additional work should test further relations to growth, maturation and development, focusing on any adverse effect from exposure to a television screen also on obesity from a neuro-hormonal viewpoint, quite apart from any decreased activity and/or other lifestyle alterations associated with watching TV.     

Energy Balance Related Behaviour: Personal,Home- and Friend-Related Factors among Schoolchildren in Europe Studied in the ENERGY-Project

Objective

To design interventions that target energy balance-related behaviours, knowledge of primary schoolchildren''s perceptions regarding soft drink intake, fruit juice intake, breakfast consumption, TV viewing and physical activity (PA) is essential. The current study describes personal beliefs and attitudes, home- and friend-related variables regarding these behaviours across Europe.

Design

Cross-sectional study in which personal, family and friend -related variables were assessed by validated questionnaires, and dichotomized as favourable versus unfavourable answers. Logistic regression analyses were conducted to estimate proportions of children giving unfavourable answers and test between-country differences.

Setting

A survey in eight European countries.

Subjects

A total of 7903 10–12 year old primary schoolchildren.

Results

A majority of the children reported unfavourable attitudes, preferences and subjective norms regarding soft drink, fruit juice intake and TV viewing accompanied with high availability and accessibility at home. Few children reported unfavourable attitudes and preferences regarding breakfast consumption and PA. Many children reported unfavourable health beliefs regarding breakfast consumption and TV viewing. Substantial differences between countries were observed, especially for variables regarding soft drink intake, breakfast consumption and TV viewing.

Conclusion

The surveyed children demonstrated favourable attitudes to some healthy behaviours (PA, breakfast intake) as well as to some unhealthy behaviours (soft drink consumption, TV viewing). Additionally, many children across Europe have personal beliefs and are exposed to social environments that are not supportive to engagement in healthy behaviours. Moreover, the large differences in personal, family and friend-related variables across Europe argue for implementing different strategies in the different European countries.     

Embryonic stem cell gene targeting using bacteriophage lambda vectors generated by phage-plasmid recombination.

Targeted mutagenesis is an extremely useful experimental approach in molecular medicine, allowing the generation of specialized animals that are mutant for any gene of interest. Currently the rate determining step in any gene targeting experiment is construction of the targeting vector (TV). In order to streamline gene targeting methods and avoid problems encountered with plasmid TVs, we describe the direct application of lambda phage in targeted mutagenesis. The recombination-proficient phage vector lambda2TK permits generation of TVs by conventional restriction-ligation or recombination-mediated methods. The resulting lambdaTV DNA can then be cleaved with restriction endonucleases to release the bacteriophage arms and can subsequently be electroporated directly into ES cells to yield gene targets. We demonstrate that in vivo phage-plasmid recombination can be used to introduce neo and lacZ - neo mutations into precise positions within a lambda2TK subclone via double crossover recombination. We describe two methods for eliminating single crossover recombinants, spi selection and size restriction, both of which result in phage TVs bearing double crossover insertions. Thus TVs can be easily and quickly generated in bacteriophage without plasmid subcloning and with little genomic sequence or restriction site information.     

Retro-recombination screening of a mouse embryonic stem cell genomic library

Targeted gene disruption is an important tool in molecular medicine, allowing for the generation of animal models of human disease. Conventional methods of targeting vector (TV) construction are difficult and represent a rate limiting step in any targeting experiment. We previously demonstrated that bacteriophage are capable of acting as TVs directly, obviating the requirement for ‘rolling out’ plasmids from primary phage clones and thus eliminating an additional, time consuming step. We have also developed methods which facilitate the construction of TVs using recombination. In this approach, modification cassettes and point mutations are shuttled to specific sites in phage TVs using phage–plasmid recombination. Here, we report a further improvement in TV generation using a recombination screening-based approach deemed ‘retro-recombination screening’ (RRS). We demonstrate that phage vectors containing specific genomic clones can be genetically isolated from a λTK embryonic stem cell genomic library using a cycle of integrative recombination and condensation. By introducing the gam gene of bacteriophage λ into the probe plasmid it is possible to select for positive clones which have excised the plasmid, thus returning to their native conformation following purification from the library. Rapid clone isolation using the RRS protocol provides another method by which the time required for TV construction may be further reduced.     

Alcohol Advertising in Sport and Non-Sport TV in Australia,during Children’s Viewing Times

Estimate the amount of alcohol advertising in sport vs. non-sport programming in Australian free-to-air TV and identify children’s viewing audience composition at different times of the day. Alcohol advertising and TV viewing audience data were purchased for free-to-air sport and non-sport TV in Australia for 2012. We counted alcohol advertisements in sport and non-sport TV in daytime (6am-8.29pm) and evening periods (8.30pm-11.59pm) and estimated viewing audiences for children and young adults (0–4 years, 5–13 years, 14–17 years, 18–29 years). During the daytime, most of the alcohol advertising (87%) was on sport TV. In the evening, most alcohol advertising (86%) was in non-sport TV. There was little difference in the mean number of children (0–17 years) viewing TV in the evening (N = 273,989), compared with the daytime (N = 235,233). In programs containing alcohol advertising, sport TV had a greater mean number of alcohol adverts per hour (mean 1.74, SD = 1.1) than non-sport TV (mean 1.35, SD = .94). Alcohol advertising during the daytime, when large numbers of children are watching TV, is predominantly in free-to-air sport TV. By permitting day-time advertising in sport programs and in any programs from 8.30pm when many children are still watching TV, current regulations are not protecting children from exposure to alcohol advertising.     

Associations of Sedentary Behavior,Sedentary Bouts and Breaks in Sedentary Time with Cardiometabolic Risk in Children with a Family History of Obesity

Background

Although reports in adults suggest that breaks in sedentary time are associated with reduced cardiometabolic risk, these findings have yet to be replicated in children.

Purpose

To investigate whether objectively measured sedentary behavior, sedentary bouts or breaks in sedentary time are independently associated with cardiometabolic risk in a cohort of Canadian children aged 8–11 years with a family history of obesity.

Methods

Data from 286 boys and 236 girls living in Quebec, Canada, with at least one biological parent with obesity (QUALITY cohort) were collected from 2005–2008, and analyzed in 2013. Sedentary behavior, light and moderate-to-vigorous physical activity were measured over 7 days using accelerometry. Leisure time computer/video game use and TV viewing over the past 7 days were self-reported. Outcomes included waist circumference, body mass index Z-score, fasting insulin, fasting glucose, triglycerides, HDL-cholesterol, C-reactive protein and a continuous cardiometabolic risk score.

Results

After adjustment for confounders, breaks in sedentary time and the number of sedentary bouts lasting 1–4 minutes were associated with reduced cardiometabolic risk score and lower BMI Z-score in both sexes (all p<0.05). The number of sedentary bouts lasting 5–9 minutes was negatively associated with waist circumference in girls only, while the number of bouts lasting 10–14 minutes was positively associated with fasting glucose in girls, and with BMI Z-score in boys (all p<0.05). Leisure time computer/video game use was associated with increased cardiometabolic risk score and waist circumference in boys, while TV viewing was associated with increased cardiometabolic risk, waist circumference, and BMI Z-score in girls (all p<0.05).

Conclusions

These results suggest that frequent interruptions in sedentary time are associated with a favourable cardiometabolic risk profile and highlight the deleterious relationship between screen time and cardiometabolic risk among children with a family history of obesity.     

Wellness programs: a review of the evidence

OBJECTIVE: To review studies that have examined an association between wellness programs and improvements in quality of life and to assess the strength of the scientific evidence. DATA SOURCES: A MEDLINE search was constructed with the following medical subject headings: "psychoneuroimmunology," "chronic disease" and "health promotion," "chronic disease" and "health behaviour," "relaxation techniques," "music therapy," "laughter," "anger," "mediation" and "behavioural medicine." Searches using the text words "wellness" and "wellness program" were also carried out. References from the primary articles identified in the search and contemporary writing on wellness were also considered. STUDY SELECTION: Selection was limited to randomized controlled trials or prospective studies published in English that involved human subjects and that took place between 1980 and 1996. All studies with an intervention aimed at promoting wellness and measuring outcomes were included, except studies of patients with cancer and HIV and studies of health promotion programs in the workplace. Of the 1082 references initially identified, 11 met the criteria for inclusion in the critical appraisal. DATA EXTRACTION: The following information was extracted from the 11 studies: characteristics of the study population, number of participants (and number followed to completion), length of follow-up, type of intervention, outcome measures and results. All 11 studies were assessed for the quality of their evidence. DATA SYNTHESIS: All studies reported some positive outcomes following the intervention in question, although many had limitations precluding applicability of the results to a wider population. CONCLUSIONS: Despite the suggested benefit associated with wellness programs, the evidence was inconclusive. Whether the composition of the target group or the type of intervention has a role in determining outcomes is unknown. Although trends suggest that wellness programs may be cost-effective, further research is needed for confirmation.     

TV viewing, computer game playing and nightmares in school children.

Often the question arises whether TV viewing or playing computer games, especially those of violent and aggressive content, has negative effects on children's sleep patterns and dreaming. Empirical data on this topic, however, are scarce. Two hundred fifty-two schoolchildren (range: 9 to 13 years) completed a questionnaire about media use and nightmares. The findings indicates that interindividual differences in nightmare frequency were not explained by interindividual differences in TV viewing or computer game playing habits. In addition, no effect of the TV films the evening before completing the questionnaire on the dreams the subsequent night could be demonstrated. Since the approach could not rule out an effect of media use habits on nightmares, the next step will be a longitudinal study eliciting the media use habits and the occurrence of nightmares by applying self-rated scales as well as information obtained by parents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of clinical practice guidelines on patient outcomes in primary care: a systematic review

OBJECTIVE: To assess the evidence for the effectiveness of clinical practice guidelines (CPGs) in improving patient outcomes in primary care. DATA SOURCES: A search of the MEDLINE, HEALTHPLAN, CINAHL and FAMLI databases was conducted to identify studies published between Jan. 1, 1980, and Dec. 31, 1995, concerning the use of guidelines in primary medical care. The keywords used in the search were "clinical guidelines," "primary care," "clinical care," "intervention," "randomized controlled trial" and "effectiveness." STUDY SELECTION: Studies of the use of CPGs were selected if they involved a randomized experimental or quasi-experimental method, concerned primary care, were related to clinical care and examined patient outcomes. Of 91 trials of CPGs identified through the search, 13 met the criteria for inclusion in the critical appraisal. DATA EXTRACTION: The following data were extracted, when possible, from the 13 trials: country and setting, number of physicians, number of patients (and the proportion followed to completion), length of follow-up, study method (including random assignment method), type of intervention, medical condition treated and effect on patient outcomes (including clinical and statistical significance, with confidence intervals). DATA SYNTHESIS: The most common conditions studied were hypertension (7 studies), asthma (2 studies) and cigarette smoking (2 studies). Four of the studies followed nationally developed guidelines, and 9 used locally developed guidelines. Six studies involved computerized or automated reminder systems, whereas the others relied on small-group workshops and education sessions. Only 5 of the 13 trials (38%) produced statistically significant results. CONCLUSION: There is very little evidence that the use of CPGs improves patient outcomes in primary medical care, but most studies published to date have used older guidelines and methods, which may have been insensitive to small changes in outcomes. Research is needed to determine whether the newer, evidence-based CPGs have an effect on patient outcomes.     

The association of television and video viewing with fast food intake by preschool-age children

Objective: To examine the extent to which television (TV) and video viewing is associated with consumption of fast food by preschool‐age children. Research Methods and Procedures: In a cross‐sectional study of 240 parents of children ages 2.0 to 5.9 years, parents reported the number of hours their child watched TV/videos on an average weekday and weekend day in the past month; a daily, weighted average of TV/video viewing was then calculated. The main outcome was parents’ report of their children's fast food intake, using the question, “How many times a week does your child eat at fast food restaurants such as McDonald's, Burger King, or Kentucky Fried Chicken?” dichotomized to (never/<1 vs. ≥1 time/wk). The association of TV/video viewing with fast food intake was evaluated by multiple logistic regression before and after adjusting for several potential confounders. Results: Twenty‐two percent of parents reported that their child ate at fast food restaurants at least once per week. After adjusting for parents’ age, race/ethnicity, and household income as well as child's age and sex, for each 1‐hour increase of TV/video watched per day, the odds ratio (OR) for consuming fast food ≥1 time per week was 1.60 (95% confidence interval, 1.03 to 2.49). After further adjustment for socio‐environmental factors that might serve as proxies for the availability of healthy food options, such as parental time constraints and the availability and high cost of fresh fruits and vegetables in their neighborhoods, the OR for consuming fast food ≥1 time per week was minimally attenuated (OR, 1.55; 95% confidence interval, 1.04 to 2.31). Discussion: TV/video viewing was correlated with fast food consumption among preschool children in this study. Our findings raise the possibility that greater exposure to TV and videos may influence preschool children's consumption of unhealthful foods.     

The Obesogenic Quality of the Home Environment: Associations with Diet,Physical Activity,TV Viewing,and BMI in Preschool Children

Objectives

The home environment is thought to play a key role in early weight trajectories, although direct evidence is limited. There is general agreement that multiple factors exert small individual effects on weight-related outcomes, so use of composite measures could demonstrate stronger effects. This study therefore examined whether composite measures reflecting the ‘obesogenic’ home environment are associated with diet, physical activity, TV viewing, and BMI in preschool children.

Methods

Families from the Gemini cohort (n = 1096) completed a telephone interview (Home Environment Interview; HEI) when their children were 4 years old. Diet, physical activity, and TV viewing were reported at interview. Child height and weight measurements were taken by the parents (using standard scales and height charts) and reported at interview. Responses to the HEI were standardized and summed to create four composite scores representing the food (sum of 21 variables), activity (sum of 6 variables), media (sum of 5 variables), and overall (food composite/21 + activity composite/6 + media composite/5) home environments. These were categorized into ‘obesogenic risk’ tertiles.

Results

Children in ‘higher-risk’ food environments consumed less fruit (OR; 95% CI = 0.39; 0.27–0.57) and vegetables (0.47; 0.34–0.64), and more energy-dense snacks (3.48; 2.16–5.62) and sweetened drinks (3.49; 2.10–5.81) than children in ‘lower-risk’ food environments. Children in ‘higher-risk’ activity environments were less physically active (0.43; 0.32–0.59) than children in ‘lower-risk’ activity environments. Children in ‘higher-risk’ media environments watched more TV (3.51; 2.48–4.96) than children in ‘lower-risk’ media environments. Neither the individual nor the overall composite measures were associated with BMI.

Conclusions

Composite measures of the obesogenic home environment were associated as expected with diet, physical activity, and TV viewing. Associations with BMI were not apparent at this age.     

Television Viewing Time in Hong Kong Adult Population: Associations with Body Mass Index and Obesity

Background

Obesity is increasing dramatically in the Asia-Pacific region particularly China. The population of Hong Kong was exposed to modernization far earlier than the rest of China, reflecting conditions that are likely to be replicated as other Chinese cities undergo rapid change. This study examined the relationship between television viewing and obesity in a Hong Kong sample. Information about the relationship between a key sedentary behavior, TV viewing, and obesity, and its moderation by demographic characteristics may identify sectors of the population at highest risk for excess weight.

Methods

Data were from Hong Kong Family and Health Information Trends Survey (2009–2010), a population-based survey on the public''s use of media for health information and family communication by telephone interviews with 3,016 Hong Kong adults (age≥18 years). TV viewing time, body mass index (BMI), physical activity and other lifestyle variables were analyzed.

Results

Viewing time was longer in women, increased with age but decreased with education level and vigorous physical activity (all P<0.01). Longer TV viewing time was significantly associated with higher BMI (Coefficients B = 0.17, 95% CI: 0.11, 0.24) after adjusting for age, gender, employment status, marital status, education level, smoking activity and vigorous physical activity. This association was stronger in women than men (Coefficients B: 0.19 versus 0.15) and strongest in those aged 18 to 34 years (Coefficients B = 0.35). Furthermore, an hour increase in daily TV viewing was associated with 10% greater odds of being obese.

Conclusions

A significant socioeconomic gradient in television viewing time was observed. TV viewing time positively associated with BMI and obesity. The TV viewing – BMI associations were strongest in women and young adults, suggesting vulnerable groups to target for obesity prevention by decreasing TV viewing.     

Relationship Between Self‐report and an Objective Measure of Television‐viewing Time in Adults

This study compared self‐reported television (TV)‐viewing time with an objective measure obtained by an electronic TV monitor. As part of a larger study, 40 overweight and obese adults (BMI: 31.7 ± 5.4 kg/m²; 53% obese; mean age 41.4 ± 13.0) self‐reported TV‐viewing time at study entry as the response to the question, “How many hours do you watch TV per day, on average?” Objective TV‐viewing time was measured in min/day over 3 weeks/subject using electronic monitors. Self‐reported viewing time was 4.3 ± 1.3 h/day (mean ± s.d.) (range: 3.0–8.0 h/day) vs. 4.9 ± 2.6 h/day (0.8–13.3 h/day) recorded by the electronic TV monitor. Subjects underestimated their viewing time by 0.6 ± 2.3 h/day (95% confidence interval = ?1.34, 0.13), or 4.3 h/week. Slightly over half of the subjects (58%) underestimated their viewing time; 47.5% were within 1 h/day, and 72.5% were within 2 h/day of self‐reported viewing time. Large errors were rare in this group, suggesting that a simple self‐report measure of TV time may be useful for characterizing viewing behavior, although objective measurement adds precision that may be useful in certain settings.