College students report less physical activity and more sedentary behavior during the COVID-19 pandemic

Objective: To understand the impact of the COVID-19 pandemic on college students' movement behaviors. Participants: College students attending a large Midwestern university during the pandemic. Methods: The Activity Questionnaire for Adults and Adolescents estimated physical activity and sedentary time before, early, and later in the pandemic. Barriers and facilitators to physical activity were assessed at early and later timepoints. Open-ended questions examined additional impacts. Results: Comparing before vs. early/later pandemic assessments, respondents (n = 230, 82% female, 21 ± 5 years) reported a significant decrease in physical activity metabolic equivalent (MET)-minutes/week (7891 ± 7340 vs. 5550 ± 6410/5953 ± 5180) and a significant increase in sedentary MET-minutes/week (1330 ± 1570 vs. 2415 ± 1770/1767 ± 1652). The top barrier was schoolwork (47.7%). The top facilitator was social support (21.5%). Responses to open-ended questions indicated that most individuals reported sitting more during the pandemic, with variation in physical activity patterns. Conclusions: Adverse changes in physical activity and sedentary behavior observed early in the pandemic were sustained.

Association between Physical Activity, Sedentary Behavior, Satisfaction with Sleep Fatigue Recovery and Smartphone Dependency among Korean Adolescents: An Age- and Gender-Matched Study

The purpose of this study was to identify the association between physical activity (PA), sedentary behavior (SB), satisfaction with sleep fatigue recovery (SSFR), and smartphone dependency in South Korean adults. We analyzed data from the National Health and Nutrition Examination Survey 2020 data. We selected participants who answered Internet addiction-related questions as “Very much” (n = 241) and answered Internet addiction-related questions as “Not at all” (n = 241) in the questionnaire. The participants were matched by age and gender, then divided into two groups. Between the two groups, there were considerable differences in the number of days participating in moderate to vigorous PA (5 days or more, p = 0.01), the number of strength training days (1 day, p = 0.02), the number of light PA days for more than 60 min (every day for the last 7 days, p = 0.01), and the SSFR over the past 7 days (p < 0.05). Additionally, the mean smartphone usage time and mean sedentary behavior time between the two groups showed significant differences. The study demonstrated that there were significant associations between PA, SB, SSFR, and smartphone dependency among Korean adolescents matched by age and gender. Additionally, this study highlights the importance of increasing overall PA and number of days participating in MVPA, decreasing SB time and smartphone usage time could reduce the incidence of smartphone overdependence.

Association of a Healthy Lifestyle with All-Cause, Cause-Specific Mortality and Incident Cancer among Individuals with Metabolic Syndrome: A Prospective Cohort Study in UK Biobank

This study investigated the association between a healthy lifestyle with all-cause, cause-specific mortality, and cancer incidence among individuals with metabolic syndrome (MetS). Healthy lifestyle scores were created based on MetS management guidelines, including never/quitting smoking, moderate drinking, good sleep, healthy diet, sufficient exercise, social support, and less sedentary behaviour. Weighted healthy lifestyle scores were further constructed and classified into three groups: unfavourable (lowest quintile), intermediate (quintiles 2−4), and favourable (highest quintile) lifestyles. We included 87,342 MetS participants from the UK Biobank. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using multivariate-adjusted Cox proportional hazards regression. During a median follow-up of 12.54 years, 6739 deaths were reported; during a median follow-up of 10.69 years, 10,802 new cancer cases were documented. We found a favourable lifestyle was inversely associated with all-cause mortality (HR: 0.57; 95%CI: 0.53−0.62), cause-specific mortality from respiratory disease, cancer, digestive disease, cardiovascular disease (HR < 1; p-trend < 0.001), and overall cancer incidence (HR: 0.84; 95% CI: 0.79−0.90). Our results indicate that adherence to healthy lifestyles is associated with lower overall cancer incidence and all-cause mortality risk among MetS individuals. However, causality cannot be made due to the nature of observational studies.

Associations of changes in physical activity and discretionary screen time with incident obesity and adiposity changes: longitudinal findings from the UK Biobank

BACKGROUND

Physical activity (PA) and discretionary screen time (DST; television and computer use during leisure) are both associated with obesity risk, but little longitudinal evidence exists on their combined influence. This study examined the independent and joint associations of changes in PA and DST with incident obesity, body mass index (BMI) and waist circumference (WC).

METHODS

We analysed the data of individuals aged 40-69 years from the UK Biobank, a large-scale, population-based prospective cohort study. PA was measured using the International Physical Activity Questionnaire and DST was defined as the total of daily TV viewing and non-occupational computer use. Changes in PA and DST over time were defined using departure from sex-specific baseline tertiles and categorised as worsened (PA decreased/DST increased), maintained, and improved (PA increased/DST decreased). We then used each exposure change to define a joint PA-DST change variable with nine mutually exclusive groups. We used multivariable adjusted mixed-effects linear and Poisson models to examine the independent and joint associations between PA and DST changes with BMI and WC and incident obesity, respectively. Development of a BMI ≥ 30 kg/m² was defined as incident obesity.

RESULTS

Among 30,735 participants, 1,628 (5.3%) developed incident obesity over a mean follow-up of 6.9 (2.2) years. In the independent association analyses, improving PA (Incident Rate Ratio (IRR) 0.46 (0.38-0.56)) was associated with a lower risk of incident obesity than maintaining PA, maintaining DST, or improving DST. Compared to the referent group (both PA and DST worsened), all other combinations of PA and DST changes were associated with lower incident obesity risk in the joint association analyses. We observed substantial beneficial associations in the improved PA groups, regardless of DST change [e.g., DST worsened (IRR 0.31 (0.21-0.44)), maintained (IRR 0.34 (0.25-0.46)), or improved (IRR 0.35 (0.22-0.56)]. The most pronounced decline in BMI and WC was observed when PA was maintained or improved and DST was maintained.

CONCLUSION

We found that improved PA had the most pronounced beneficial associations with incident obesity, irrespective of DST changes. Improvements in PA or DST mutually attenuated the deleterious effects of the other behaviour's deterioration.

Correlates of Sedentary Behavior among Bhutanese Adults: Findings from the 2014 Bhutan STEPS Survey Data

Background

Sedentary behavior is associated with several adverse health outcomes. Data on factors that influence sedentary behavior are lacking in Bhutan. This study examined factors associated with increased sedentary behavior in Bhutan, with a focus on exploring sex differences.

Methods

Data of 2,796 adults from the nationally representative 2014 Bhutan STEP-wise surveillance (STEPS) survey were analyzed. Factors associated with sedentary behavior were identified using backward elimination multiple logistic regression analysis, disaggregated by sex. The analysis accounted for the complex survey design used in the primary survey.

Results

The overall prevalence of sedentary behavior was 8.2%, with a higher proportion among women than men (10.3% vs. 4.9%). In the full sample, female sex, being single, high education and income, urban residence, inadequate physical activity, and high blood sugar were associated with increased odds of sedentary behavior. Among females, those who had high education and income, were single, physically less active, and urban residents were more likely to be sedentary. Self-employment was related to reduced odds of sedentary behavior among women and in the overall sample population. In males, being single, higher education level, and urban residence were associated with sedentariness.

Conclusion

The findings suggest that interventions targeting females, especially those who are physically less active and from higher socioeconomic groups, urban residents, and those with hyperglycemia can potentially help reduce sedentary behavior and avert the associated detrimental impacts.

Time Spent Sitting as an Independent Risk Factor for Cardiovascular Disease

Sedentary behavior is highly prevalent despite growing evidence of adverse effects on the cardiovascular and metabolic system that are independent of the level of recreational physical activity (PA). We present results for the association between sitting time and cardiovascular disease (CVD) from selected cohort and cross-sectional studies published in or after the year 2010 according to the domains where sitting time is accumulated during the day. These include TV viewing, occupational sitting, and sitting during transportation as well as overall sitting. The outcomes considered in this review are total CVD, coronary heart disease, and stroke as well as CVD risk factors-namely, hypertension, hypercholesterolemia, and type 2 diabetes and their associated biomarkers. Finally, several current issues with regard to studying the effects of sitting time on CVD are discussed, including how sedentary behavior is assessed, isotemporal substitution modeling, examination of joint associations for sitting and PA, and benefits of breaks in sitting time. Overall, the scientific evidence supports public health recommendations that encourage adults to limit their sedentary time in order to improve their cardiovascular health.

Effects of media-assisted therapeutic approaches on physical activity of obese adults: a systematic review

BACKGROUND

The number of patients with obesity continues to increase in our society. At the same time, digitalization defines our everyday life. Therefore, the question arises whether to use digital media for effective treatments against obesity. Aim of this review is a concise presentation of effects of media-assisted therapeutic approaches.

METHODS

A systematic literature research in multiple scientific databases, PubMed, Web of Science and Cochrane Library, was performed for literature published in the last 10 years (cut-off date 12.07.2017). Only randomized controlled trials using digital support for treatment and/or aftercare of obese adults aged between 18 to 70 years were included into the analysis.

RESULTS

Overall, 14 trials with data on a total of 4979 participants were included in this review. Generally, there are positive trends for increased moderate to vigorous physical activity by the use of digital media. A simultaneous usage of various digital media, which focus on important aspects of activity behavior, has proven to be effective. A combination of various digital media shows the greatest positive effect and could significantly increase physical activity. However, the biggest potential was found in mixed approaches combining digital devices and personal face-to-face support.

CONCLUSIONS

Therapeutic approaches using digital media for supporting obesity treatment did not show superior benefit over traditional personal therapeutic methods. Nevertheless, using both methods together offered the greatest potential for successful obesity therapy. However, there is a backlog of transparency concerning information about the content of treatment. Furthermore, there is a lack of valid data about aftercare and follow-up.

The Association of Sedentary Behaviour and Cognitive Function in People Without Dementia: A Coordinated Analysis Across Five Cohort Studies from COSMIC

BACKGROUND

Besides physical activity as a target for dementia prevention, sedentary behaviour is hypothesized to be a potential target in its own right. The rising number of persons with dementia and lack of any effective treatment highlight the urgency to better understand these modifiable risk factors. Therefore, we aimed to investigate whether higher levels of sedentary behaviour are associated with reduced global cognitive functioning and slower cognitive decline in older persons without dementia.

METHODS

We used five population cohorts from Greece, Australia, USA, Japan, and Singapore (HELIAD, PATH, SALSA, SGS, and SLAS2) from the Cohort Studies of Memory in an International Consortium. In a coordinated analysis, we assessed the relationship between sedentary behaviour and global cognitive function with the use of linear mixed growth model analysis (mean follow-up range of 2.0-8.1 years).

RESULTS

Baseline datasets combined 10,450 older adults without dementia with a mean age range between cohorts of 66.7-75.1 years. After adjusting for multiple covariates, no cross-sectional association between sedentary behaviour and cognition was found in four studies. One association was detected where more sedentary behaviour was cross-sectionally linked to higher cognition levels (SLAS2, B = 0.118 (0.075; 0.160), P < 0.001). Longitudinally, there were no associations between baseline sedentary behaviour and cognitive decline (P > 0.05).

CONCLUSIONS

Overall, these results do not suggest an association between total sedentary time and lower global cognition in older persons without dementia at baseline or over time. We hypothesize that specific types of sedentary behaviour may differentially influence cognition which should be investigated further. For now, it is, however, too early to establish undifferentiated sedentary time as a potential effective target for minimizing cognitive decline in older adults without dementia.

Health Capability and Psychological Effects of Regular Exercise on Adults: Middle-Aged and Older

This study sought to determine whether there is any difference on participation in regular exercise between middle-aged and older adults and to determine whether the benefits of regular exercise differed between middle-aged and older adults in terms of health capability, mood, or anxiety symptoms and life-satisfaction level. The results indicated that older adults engaged in regular exercise more frequently than middle-aged adults. In addition, exercise participants among middle-aged adults had the better health capabilities, lower depression and anxiety symptoms, and higher life-satisfaction level than nonparticipants. On the other hands, older adults tended to be negatively associated with depression and anxiety symptoms and be positively correlated with life-satisfaction level than middle-aged adults even if middle-aged adults had the better health capabilities. These findings might be beneficial to provide appropriate exercise programs, to prevent and minimize the negative symptoms of anxiety and depression, and to facilitate the life-satisfaction level.

Faithful Families Cooking and Eating Smart and Moving for Health: Evaluation of a Community Driven Intervention

Background: There is an increasing need to adapt and use community interventions to address modifiable behaviors that lead to poor health outcomes, like obesity, diabetes, and heart disease. Poor health outcomes can be tied to community-level factors, such as food deserts and individual behaviors, like sedentary lifestyles, consuming large portion sizes, and eating high-calorie fast food and processed foods. Methods: Through a social ecological approach with family, organization and community, the Faithful Families Cooking and Eating Smart and Moving for Health (FFCESMH) intervention was created to address these concerns in a rural South Carolina community. FFCESMH used gatekeepers to identify 18 churches and four apartment complexes in low-income areas; 176 participants completed both pre- and post-survey measures. Results: Paired t-test measures found statistically significant change in participant perception of food security (0.39, p-value = 0.005, d = 0.22), self-efficacy with physical activity and healthy eating (0.26, p-value = 000, d = 0.36), and cooking confidence (0.17, p-value = 0.01, d = 0.19). There was not significant change in cooking behaviors, as assessed through the Cooking Behaviors Scale. Conclusion: FFCESMH shows that a social ecological approach can be effective at increasing and improving individual healthy behaviors and addressing community-level factors in low-income rural communities.

Joint Association of Screen Time and Physical Activity with Obesity: Findings from the Korea Media Panel Study

Objectives

There is evidence to suggest that sedentary behavior is associated with a higher risk of metabolic disease. The aim of this study was to investigate cross-sectional joint associations of physical activity (PA) and screen time (ST), with the risk of obesity in Korean adults.

Methods

The Korea Media Panel Study consisted of a household interview and a self-administered diary survey on media usage over 3 days. ST (hours/day) was defined as the reported daily average hours spent watching television, computing (i.e., desktop, notebook, netbook, tablets), smartphone and video game console use. Cross-sectional associations of obesity (BMI ≥ 25 kg/m²) and the amount of daily ST and PA were examined by logistic regression models adjusting for other possible confounders including alcohol consumption, smoking, depressive symptoms and demographic information. There were 7,808 participants included in the analyses.

Results

Increased ST was significantly associated with the risk of obesity (controlling for other possible confounders), but PA level was not found to be significantly linked. Participants who engaged in screen time > 6 hours per day had a higher incidence of obesity.

Conclusion

This study provides evidence of the association between ST and the increased incidence of obesity measured by BMI, independent of PA amongst Korean adults.

Does dietary intake change during an intervention to reduce sedentary behavior and cardiovascular disease risk? A randomized comparative effectiveness trial

BACKGROUND

Evidence from physical activity interventions suggests that women, in particular, may overcompensate for exercise energy expenditure by increasing caloric intake. Sedentary behavior and poor dietary quality are independent risk factors for many major chronic diseases, including cardiovascular disease (CVD). The primary purpose of this study was to determine whether insufficiently active women, accumulating less than 60 min per week of moderate-to-vigorous physical activity, alter caloric intake or dietary quality when participating in an 8-week intervention to reduce sedentary behavior and CVD risk. A secondary aim was to determine whether the two treatment groups differed from one another in dietary intake while participating in the intervention.

METHODS

Insufficiently active women (n = 49) working full-time sedentary jobs were randomized to one of two treatment groups to reduce sedentary behavior during the workweek: short-break (1-2 min breaks from sitting every half hour, SB), or long-break (15 min breaks from sitting twice daily, LB). Three-day food records were collected at baseline, week 4 and week 8. Dietary quality was assessed using the Alternative Healthy Eating Index 2010 (AHEI-2010). Risk factors for CVD were assessed at baseline and week 8.

RESULTS

For all participants, average caloric intake decreased significantly from baseline to week 8 by approximately 12% (∆ = - 216.0 kcals, p = 0.003). Average caloric intake decreased significantly over time for the SB group (∆ = - 369.6 kcals, p = 0.004), but not the LB group (∆ = - 179.5 kcals, p = 0.17). There was no significant difference between SB and LB groups with regard to calories from baseline to week 8 (F = 0.51, p = 0.48). Total AHEI-2010 scores did not decrease significantly for all participants (∆ = - 4.0, p = 0.14), SB (∆ = - 5.2, p = 0.16), or LB groups (∆ = - 4.5, p = 0.67).

CONCLUSIONS

Following an 8-week intervention to reduce sedentary time, insufficiently active women decreased caloric intake over time, however there were no differences between SB and LB groups. In all participants, dietary quality was not altered over time. Future studies should explore sedentary reduction interventions compared to physical activity interventions as a means to create negative energy balance, as frequent sedentary breaks may be effective for improving health outcomes in women.

TRIAL REGISTRATION

ClinicalTrials.gov registration number NCT02609438, retrospectively registered November 20, 2015.

Twelve-Year Television Viewing Time Trajectories and Physical Function in Older Adults

INTRODUCTION

The purposes of this study were to identify trajectories of older adults' television viewing (TV) time for 12 yr and to examine their associations with performance-based measures of physical function.

METHODS

Data on TV time (h·wk) and sociodemographic factors were collected at each assessment of the Australian Diabetes, Obesity and Lifestyle Study (1999/2000, 2004/2005, and 2011/2012), with objective measures of physical function (2.44 m timed up and go [TUG, s] and knee extensor strength [KES, kg] tests) collected at the final (2011/2012) assessment. Regression analyses examined predictors of trajectory membership and associations with TUG and KES in those 60+ yr of age in 2011/2012.

RESULTS

Six TV time trajectories were identified among the 1938 participants (age, 60-97 yr; 54% female): consistently low (9.7%), low-increasing (22.3%), moderate-decreasing (13.5%), moderate-increasing (30.3%), consistently high (18.9%), and high-increasing (5.2%). There were no statistically significant relationships with TUG (P > 0.05). In the fully adjusted model, KES performance was significantly better in the consistently low, low-increasing, and consistently high trajectories, compared with the moderate-increasing trajectory (P < 0.001, R = 0.33).

CONCLUSION

Twelve-year trajectories of TV time were associated with muscle strength in older adults. These findings suggest that patterns of sedentary behavior can be a determinant of muscle strength in later life.

Comparison of passive and active leisure activities and life satisfaction with aging

AIM

Many older adults face limitations to participating in active leisure activities as a result of their physical constraints from aging. Passive leisure activities become alternative leisure activities for older adults as a result of limited physical capacity. The present study sought to determine whether there exists a difference in the frequency of participation in passive and active leisure activities, and the effect of participation in passive and active leisure activities on the life satisfaction level of old adults.

METHODS

A total of 460 participants aged 60-95 years were randomly selected from 21 sites in the USA. The Life Satisfaction Index - Z and the Meaningful Activity Participation Assessment were analyzed to examine older adults' life satisfaction and frequency of active or passive activities.

RESULTS

The results showed that participation in passive leisure activities, such reading, talking on the telephone and watching TV/listening to the radio, is more frequent among older adults (P = 0.000). The regression coefficient found that club/organization or volunteering (P = 0.008), homemaking/maintenance (P = 0.017) and traveling (P = 0.017) for active leisure activities were statistically significant predictors of Life Satisfaction Index - Z for older adults.

CONCLUSIONS

The current study shows that older adults spent much more times participating in passive leisure activities, such as radio/watching TV, talking on the phone and reading. The result also showed that active leisure activities, such as club/organization or volunteering, home making/maintenance and traveling, were significant predictors of life satisfaction for older adults controlling for covariates. The current study suggests marketing and programming plans to overcome the constraints that influence older adults' life satisfaction. Geriatr Gerontol Int 2018; 18: 380-386.

The effect of television watching and portion size on intake during a meal

Watching television while eating and eating from larger portion sizes of food are factors that have been found to independently increase food intake. When combined, these factors may further enhance consumption. This investigation, using a 4 × 2 × 2 mixed factorial design, with a between-subjects factor of order of conditions and within-subjects factors of television watching (NO TV and TV) and portion size (SMALL and LARGE), tested the independent effects and interaction of these factors in seventeen women and three men (21.6 ± 2.3 kg/m², 22.3 ± 3.7 years, 80% white and 95% non-Hispanic). In each condition, participants had 30 min to eat a meal containing macaroni and cheese and salad with dressing. For NO TV, participants sat for 30 min while eating, while for TV, participants viewed a 30-min show containing no food cues while eating. In SMALL the meal provided 1083 kcal, while in LARGE the meal provided 200% of SMALL. Mixed factorial analysis of variance revealed a significant main effect of portion size on grams and energy consumed of the total meal. Participants consumed more grams (577.9 ± 150.5 g vs. 453.1 ± 96.6 g; p < 0.001) and energy (903.9 ± 270.4 kcal vs. 734.6 ± 187.1 kcal; p < 0.001) in LARGE as compared to SMALL. No significant effect of television watching or interaction of television watching and portion size was found. Results of this study suggest that to assist with reducing intake, smaller portion sizes should be implemented in all types of eating situations.

Sitting time and obesity in a sample of adults from Europe and the USA

BACKGROUND

Obesity is a risk factor for many chronic diseases and the prevalence is increasing worldwide. Research suggests that sedentary behaviour (sitting) may be related to obesity.

AIM

To examine the association between sitting time and obesity, while controlling for physical activity, in a large international sample.

SUBJECTS AND METHODS

In total, 5338 adults from the UK, USA, Germany, Spain, Italy, France, Portugal, Austria and Switzerland self-reported their total daily sitting time, physical activity, age, height and weight. BMI (kg/m²), total physical activity (MET-minutes/week) and sitting time (hours/day) were derived. Participants were grouped into quartiles based on their daily sitting time (<4, 4-≤6, 6-≤8 and >8 hours/day) and logistic regression models explored the odds of being obese vs normal weight for each sitting time quartile.

RESULTS

Participants in the highest sitting time quartile (≥8 hours/day) had 62% higher odds of obesity compared to participants in the lowest quartile (<4 hours/day) after adjustment for physical activity and other confounding variables (OR = 1.62, 95% CI = 1.24-2.12, p < .01).

CONCLUSION

Sitting time is associated with obesity in adults, independent of physical activity. Future research should clarify this association using objective measures of sitting time and physical activity to further inform health guidelines.

Investigating the influence of eating habits, body weight and television programme preferences on television viewing time and domestic computer usage

Background:

The present study explored the influence of eating habits, body weight and television programme preference on television viewing time and domestic computer usage, after adjusting for sociodemographic characteristics and home media environment indicators. In addition, potential substitution or complementarity in screen time was investigated.

Methods:

Individual level data were collected via questionnaires that were administered to a random sample of 2,946 Germans. The econometric analysis employed a seemingly unrelated bivariate ordered probit model to conjointly estimate television viewing time and time engaged in domestic computer usage.

Results:

Television viewing and domestic computer usage represent two independent behaviours in both genders and across all age groups. Dietary habits have a significant impact on television watching with less healthy food choices associated with increasing television viewing time. Body weight is found to be positively correlated with television screen time in both men and women, and overweight individuals have a higher propensity for heavy television viewing. Similar results were obtained for age groups where an increasing body mass index (BMI) in adults over 24 years old is more likely to be positively associated with a higher duration of television watching. With respect to dietary habits of domestic computer users, participants aged over 24 years of both genders seem to adopt more healthy dietary patterns. A downward trend in the BMI of domestic computer users was observed in women and adults aged 25–60 years. On the contrary, young domestic computer users 18–24 years old have a higher body weight than non-users. Television programme preferences also affect television screen time with clear differences to be observed between genders and across different age groups.

Conclusions:

In order to reduce total screen time, health interventions should target different types of screen viewing audiences separately.

Objectively measured physical activity and sedentary-time are associated with arterial stiffness in Brazilian young adults

OBJECTIVE

To examine the associations between objectively measured physical activity and sedentary time with pulse wave velocity (PWV) in Brazilian young adults.

METHODS

Cross-sectional analysis with participants of the 1982 Pelotas (Brazil) Birth Cohort who were followed-up from birth to 30 years of age. Overall physical activity (PA) assessed as the average acceleration (mg), time spent in moderate-to-vigorous physical activity (MVPA - min/day) and sedentary time (min/day) were calculated from acceleration data. Carotid-femoral PWV (m/s) was assessed using a portable ultrasound. Systolic and diastolic blood pressure (SBP/DBP), waist circumference (WC) and body mass index (BMI) were analyzed as possible mediators. Multiple linear regression and g-computation formula were used in the analyses.

RESULTS

Complete data were available for 1241 individuals. PWV was significantly lower in the two highest quartiles of overall PA (0.26 m/s) compared with the lowest quartile. Participants in the highest quartile of sedentary time had 0.39 m/s higher PWV (95%CI: 0.20; 0.57) than those in the lowest quartile. Individuals achieving ≥30 min/day in MVPA had lower PWV (β = -0.35; 95%CI: -0.56; -0.14). Mutually adjusted analyses between MVPA and sedentary time and PWV changed the coefficients, although results from sedentary time remained more consistent. WC captured 44% of the association between MVPA and PWV. DBP explained 46% of the association between acceleration and PWV.

CONCLUSIONS

Physical activity was inversely related to PWV in young adults, whereas sedentary time was positively associated. Such associations were only partially mediated by WC and DBP.

Television viewing time and risk of incident obesity and central obesity: the English longitudinal study of ageing

BACKGROUND

Research suggests television viewing time may be associated with incident obesity and central obesity in young adults. No study has investigated these associations in older English adults. The aim of this study was to investigate longitudinal associations between television viewing time and incident obesity and central obesity in a sample of older English adults. Analyses of data from the English Longitudinal Study of Ageing. At baseline (2008), participants reported their television viewing time. Research nurses recorded obesity and central obesity by body mass index and waist circumference, respectively, at four year follow-up. Associations between television viewing time and incident obesity (BMI > 30 kg/m(2)) and central obesity (waist >102 cm men; > 88 cm women) at four year follow-up were examined using adjusted logistic regression. Participants gave full written informed consent to participate in the study and ethical approval was obtained from the London Multicentre Research Ethics Committee.

RESULTS

A total of 3777 initially non-obese participants (aged 64.8 ± 8.6 yrs, 46.4% male) were included in the analyses using BMI as an outcome and 2947 for the analyses using waist circumference. No significant associations were found between television viewing time and incident obesity. A significant association was found between watching ≥6 hrs/d of television (compared to <2 hrs/d) and central obesity (Odds Ratio 1.48; 95% confidence interval 1.07 to 2.03) after adjustment for covariables including physical activity.

CONCLUSIONS

In this sample of older community dwelling English adults greater television viewing time was associated with incident central obesity, but not total obesity when measured by BMI. Interventions to reduce the incidence of central obesity in this age group that focus on reducing TV time, as well as targeting other health behaviours (eg, increasing physical activity levels, improving dietary intake) might prove useful.

Sedentary behaviour and diet across the lifespan: an updated systematic review

BACKGROUND

Sedentary behaviour and its association with dietary intake in young people and adults are important topics and were systematically reviewed in 2011. There is a need to update this evidence given the changing nature of sedentary behaviour and continued interest in this field. This review aims to assist researchers in better interpreting the diversity of findings concerning sedentary behaviour and weight status.

OBJECTIVE

To provide an update of the associations between sedentary behaviour and dietary intake across the lifespan.

METHODS

Electronic databases searched were MEDLINE, PsychInfo, Cochrane Library, Web of Science and Science Direct for publications between January 2010 and October 2013, thus updating a previous review. Included were observational studies assessing an association between at least one sedentary behaviour and at least one aspect of dietary intake in preschool children (<5 years), school-aged children (6-11 years), adolescents (12-18 years) and adults (>18 years).

RESULTS

27 papers met inclusion criteria (preschool k=3, school-aged children k=9, adolescents k=15, adults k=3). For all three groups of young people, trends were evident for higher levels of sedentary behaviour, especially TV viewing, to be associated with a less healthful diet, such as less fruit and vegetable and greater consumption of energy-dense snacks and sugar sweetened beverages. Data for the three studies with adults were less conclusive.

CONCLUSIONS

Sedentary behaviour continues to be associated with unhealthy diet in young people in mostly cross-sectional studies. More studies utilising a prospective design are needed to corroborate findings and more studies are needed with adults.

Nine year changes in sitting time in young and mid-aged Australian women: findings from the Australian Longitudinal Study for Women's Health

OBJECTIVE

To examine changes in sitting time (ST) in women over nine years and to identify associations between life events and these changes.

METHODS

Young (born 1973-78, n=5215) and mid-aged (born 1946-51, n=6973) women reported life events and ST in four surveys of the Australian Longitudinal Study on Women's Health between 2000 and 2010. Associations between life events and changes in ST between surveys (decreasers ≥2 h/day less, increasers ≥2 h/day more) were estimated using generalized estimating equations.

RESULTS

Against a background of complex changes there was an overall decrease in ST in young women (median change -0.48 h/day, interquartile range [IQR]=-2.54, 1.50) and an increase in ST in mid-aged women (median change 0.43 h/day; IQR=-1.29, 2.0) over nine years. In young women, returning to study and job loss were associated with increased ST, while having a baby, beginning work and decreased income were associated with decreased ST. In mid-aged women, changes at work were associated with increased ST, while retiring and decreased income were associated with decreased ST.

CONCLUSIONS

ST changed over nine years in young and mid-aged Australian women. The life events they experienced, particularly events related to work and family, were associated with these changes.

The association of breakfast skipping and television viewing at breakfast with weight status among parents of 10-12-year-olds in eight European countries; the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) cross-sectional study

OBJECTIVE

The main objective was to assess the relationship of breakfast skipping, television (TV) viewing at breakfast and breakfast without TV with weight status among parents of 10-12-year-olds in eight European countries.

DESIGN

A cross-sectional survey assessed breakfast eating and TV viewing at breakfast by three frequency questions and parents were categorized into: (i) breakfast skippers; (ii) breakfast with TV (TV watchers at breakfast); and (iii) breakfast without TV (breakfast eaters who do not watch TV during breakfast). Self-reported weight and height were used to categorize weight status as underweight, normal weight, overweight and obese. Multinomial logistic regression analyses were conducted with weight status as the dependent variable and breakfast habits as predictors, adjusting for sex, ethnicity and level of education.

SETTING

The survey was conducted in 2010 in 199 primary schools across eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) cross-sectional study.

SUBJECTS

Parents (n 6512) of 10-12-year-olds responded to the questionnaire.

RESULTS

In the total study sample, with breakfast without TV as the reference group and adjusting for sex, ethnicity and level of education, the OR of being respectively overweight or obese (compared with normal weight) was 1.2 (95% CI 1.0, 1.4) or 1.8 (95% CI 1.5, 2.3) for breakfast skippers. The OR of being respectively underweight or obese was 0.5 (95% CI 0.2, 0.9) or 1.4 (95% CI 1.1, 1.8) for breakfast with TV.

CONCLUSIONS

Breakfast skippers were significantly more likely to be overweight and obese, and those eating breakfast while watching TV were significantly more likely to be obese and less likely to be underweight.

A cross-sectional study of the environment, physical activity, and screen time among young children and their parents

Background

To develop evidence-based interventions promoting healthy active lifestyles among young children and their parents, a greater understanding is needed of the correlates of physical activity and screen time in these dyads. Physical environment features within neighborhoods may have important influences on both children and their parents. The purpose of this study was to examine the associations between several features of the physical environment with physical activity and screen time among 511 young children (≤5 years old) and their parents, after adjusting for socio-demographic factors.

Methods

From May to September, 2011, parents of 0–5 year old children from Kingston, Canada completed a questionnaire that assessed socio-demographic characteristics, their physical activity and screen time, and their child’s physical activity and screen time. Guided by a previously developed conceptual framework, several physical environment features were assessed using Geographic Information Systems including, function (walkability), safety (road speed), aesthetics (streetscape), and destination (outdoor play/activity space, recreation facilities, distance to closest park, yard at home). Multilevel linear regression analyses were used to examine the relationships while adjusting for several socio-demographic factors.

Results

The only independent association observed for the physical environment features was between higher outdoor play/activity space and higher screen time levels among parents. Several associations were observed with socio-demographic variables. For physical activity, child age, child care status, and family socioeconomic status (SES) were independent correlates for children while sex was an independent correlate for parents. For screen time, child age and family SES were independent correlates for children while neighborhood SES was an independent correlate for parents.

Conclusions

The findings suggest that socio-demographic factors, including social environment factors, may be more important targets than features of the physical environment for future interventions aiming to promote healthy active lifestyles in young children and their parents. Given this was one of the first studies to examine these associations in young child–parent dyads, future research should confirm and build on these findings.

Assessing physical activity in daily life, exercise, and sedentary behavior among Japanese moving to westernized environment: a cross-sectional study of Japanese migrants at an urban primary care center in Pittsburgh

BACKGROUND

Noncommunicable chronic diseases (NCDs) are global public health issues. Physical activity, exercise and sedentary behavior are important lifestyle factors to determine risk of NCDs. Immigrant studies have shown higher risk of developing NCDs among immigrants. Less physical activity among Japanese immigrants to westernized environment was also documented. However, little is known about detailed physical activity, exercise and sedentary behavior among Japanese residing in westernized environment. This cross-sectional study was conducted to analyze physical activity in daily life, exercise, and sedentary behavior among Japanese in westernized environment and then to compare the results to native Japanese in Japan.

METHODS

Japanese adults in Pittsburgh who were registered at an urban primary care clinic were surveyed in terms of physical activity in daily life, exercise, and sedentary behavior. The results were compared to age- and gender-matched Japanese averages from the national data (Japanese National Health and Nutrition Survey, J-NHANS).

RESULTS

Of 97 identified for inclusion, all responded. Japanese in Pittsburgh did not engage physical activity in daily life as compared to J-NHANS results (p < .001 for both genders). Only 45.0% and 26.3% of Japanese men and women in Pittsburgh, respectively, reached the recommended level of exercise. The prevalence of regularly engaging moderate or vigorous level of exercise was significantly lower among Japanese in Pittsburgh than age- and gender-matched J-NHANS results. The prevalence of 2 hours or more per week of exercise at moderate or higher level among Japanese men and women in Pittsburgh were lower than J-NHANS results. Women in Pittsburgh showed significantly less sedentary time as compared to J-NHANS results, while men only showed significantly less sitting/lying time during weekend. We found no association between sedentary time (time in sitting/lying and TV/computer) and exercise time during weekday or weekend in the target population.

CONCLUSIONS

Although Japanese in Pittsburgh showed lower prevalence of sedentary behavior, prevalence of regular physical activity and exercise were less than prevalence of native Japanese.

Reducing TV watching during adult obesity treatment: two pilot randomized controlled trials

The more time adults spend being sedentary, the greater the risk of obesity. The effect of reducing television (TV) watching, a prominent sedentary behavior, on weight loss has not been tested in an adult standard behavioral obesity intervention, and the mechanisms by which reducing TV watching influences energy balance behaviors are not well understood. Two, 8-week, pilot, randomized controlled trials were conducted examining the effect of a reduced TV watching prescription on energy balance behaviors and weight loss within an adult standard behavioral obesity intervention. In the first study, participants (n=24) were randomized into one of two conditions: (a) reduce energy intake and increase moderate to vigorous physical activity (MVPA) (INCREASE PA); or (b) reduce energy intake and decrease TV watching (DECREASE TV). As findings from the first pilot study did not show an increase in MVPA in the DECREASE TV group, the second study was designed to examine the effect of adding a reduced TV prescription to a standard intervention to optimize outcomes. In Pilot Study 2, participants (n=28) were randomized to INCREASE PA or to INCREASE PA+DECREASE TV. Outcomes included objectively measured TV watching and MVPA, self-reported light physical activity (LPA-Pilot Study 2 only), self-reported dietary intake while watching TV, and weight. Conditions with TV watching prescriptions significantly reduced TV watching. Both studies showed medium to large effect sizes for conditions with TV watching prescriptions to show greater reductions in dietary intake while watching TV. Pilot Study 1 found a trend for an increase in MVPA in INCREASE PA and Pilot Study 2 found significant increases in MVPA in both conditions. Pilot Study 2 found a significant increase in LPA in the INCREASE PA+DECREASE TV. Results indicate adding a TV watching prescription to a standard obesity intervention did not enhance increases in MVPA, but may assist with reducing dietary intake while TV watching and increasing LPA. Future research should examine the effect of reducing TV watching during obesity treatment over a longer time frame in a larger sample.

The relationship between cell phone use, physical and sedentary activity, and cardiorespiratory fitness in a sample of U.S. college students

BACKGROUND

Today's cell phones increase opportunities for activities traditionally defined as sedentary behaviors (e.g., surfing the internet, playing video games). People who participate in large amounts of sedentary behaviors, relative to those who do not, tend to be less physically active, less physically fit, and at greater risk for health problems. However, cell phone use does not have to be a sedentary behavior as these devices are portable. It can occur while standing or during mild-to-moderate intensity physical activity. Thus, the relationship between cell phone use, physical and sedentary activity, and physical fitness is unclear. The purpose of this study was to investigate these relationships among a sample of healthy college students.

METHODS

Participants were first interviewed about their physical activity behavior and cell phone use. Then body composition was assessed and the validated self-efficacy survey for exercise behaviors completed. This was followed by a progressive exercise test on a treadmill to exhaustion. Peak oxygen consumption (VO2 peak) during exercise was used to measure cardiorespiratory fitness. Hierarchical regression was used to assess the relationship between cell phone use and cardiorespiratory fitness after controlling for sex, self-efficacy, and percent body fat. Interview data was transcribed, coded, and Chi-square analysis was used to compare the responses of low and high frequency cell phone users.

RESULTS

Cell phone use was significantly (p = 0.047) and negatively (β = -0.25) related to cardio respiratory fitness independent of sex, self-efficacy, and percent fat which were also significant predictors (p < 0.05). Interview data offered several possible explanations for this relationship. First, high frequency users were more likely than low frequency users to report forgoing opportunities for physical activity in order to use their cell phones for sedentary behaviors. Second, low frequency users were more likely to report being connected to active peer groups through their cell phones and to cite this as a motivation for physical activity. Third, high levels of cell phone use indicated a broader pattern of sedentary behaviors apart from cell phone use, such as watching television.

CONCLUSION

Cell phone use, like traditional sedentary behaviors, may disrupt physical activity and reduce cardiorespiratory fitness.

Behavioral lifestyle intervention in the treatment of obesity

This article provides an overview of research regarding adult behavioral lifestyle intervention for obesity treatment. We first describe two trials using a behavioral lifestyle intervention to induce weight loss in adults, the Diabetes Prevention Program (DPP) and the Look AHEAD (Action for Health in Diabetes) trial. We then review the three main components of a behavioral lifestyle intervention program: behavior therapy, an energy- and fat-restricted diet, and a moderate- to vigorous-intensity physical activity prescription. Research regarding the influence of dietary prescriptions focusing on macronutrient composition, meal replacements, and more novel dietary approaches (such as reducing dietary variety and energy density) on weight loss is examined. Methods to assist with meeting physical activity goals, such as shortening exercise bouts, using a pedometer, and having access to exercise equipment within the home, are reviewed. To assist with improving weight loss outcomes, broadening activity goals to include resistance training and a reduction in sedentary behavior are considered. To increase the accessibility of behavioral lifestyle interventions to treat obesity in the broader population, translation of efficacious interventions such as the DPP, must be undertaken. Translational studies have successfully altered the DPP to reduce treatment intensity and/or used alternative modalities to implement the DPP in primary care, worksite, and church settings; several examples are provided. The use of new methodologies or technologies that provide individualized treatment and real-time feedback, and which may further enhance weight loss in behavioral lifestyle interventions, is also discussed.

Sitting time in Germany: an analysis of socio-demographic and environmental correlates

Background

Sedentary behaviour in general and sitting time in particular is an emerging global health concern. The aim of this study was to provide data on the prevalence of sitting time in German adults and to examine socio-demographic and environmental correlates of sitting time.

Methods

A representative sample of German adults (n = 2000; 967 men, 1033 women; 49.3 ±17.6 years of age) filled in the Global Physical Activity Questionnaire, including one question on overall sitting time and answered questions about the neighbourhood environment, as well as concerning demographics. Daily sitting time was stratified by gender, age group, BMI, educational and income level, as well as physical activity (PA). To identify socio-demographic and environmental correlates of sitting time, we used a series of linear regressions.

Results

The overall median was 5 hours (299 minutes) of sitting time/day and men sat longer than women (5 vs. 4 hours/day; p < 0.05). In both genders age and PA were negatively and the educational level positively associated with sitting time. The level of income was not a correlate of sitting time in multivariate analyses. Sitting time was significantly positively associated with higher neighbourhood safety for women. The variance of the multivariate model ranged from 16.5% for men to 8.9% for women.

Conclusions

The overall sitting time was unequally distributed in the German adult population. Our findings suggest implementing specific interventions to reduce sitting time for subgroups such as men, younger aged adults and adults with a higher education and lower PA. Future studies should enhance our understanding of the specific correlates of different types and domains of sitting in order to guide the development of effective public health strategies.

TV time but not computer time is associated with cardiometabolic risk in Dutch young adults

Background

TV time and total sedentary time have been positively related to biomarkers of cardiometabolic risk in adults. We aim to examine the association of TV time and computer time separately with cardiometabolic biomarkers in young adults. Additionally, the mediating role of waist circumference (WC) is studied.

Methods and Findings

Data of 634 Dutch young adults (18–28 years; 39% male) were used. Cardiometabolic biomarkers included indicators of overweight, blood pressure, blood levels of fasting plasma insulin, cholesterol, glucose, triglycerides and a clustered cardiometabolic risk score. Linear regression analyses were used to assess the cross-sectional association of self-reported TV and computer time with cardiometabolic biomarkers, adjusting for demographic and lifestyle factors. Mediation by WC was checked using the product-of-coefficient method.

TV time was significantly associated with triglycerides (B = 0.004; CI = [0.001;0.05]) and insulin (B = 0.10; CI = [0.01;0.20]). Computer time was not significantly associated with any of the cardiometabolic biomarkers. We found no evidence for WC to mediate the association of TV time or computer time with cardiometabolic biomarkers.

Conclusions

We found a significantly positive association of TV time with cardiometabolic biomarkers. In addition, we found no evidence for WC as a mediator of this association. Our findings suggest a need to distinguish between TV time and computer time within future guidelines for screen time.

The mediating effects of dietary habits on the relationship between television viewing and body mass index among youth

OBJECTIVE

There is evidence to suggest that excessive television viewing is an independent determinant of obesity in young people. However, the pathways between television viewing and obesity are not fully understood. Therefore, the purpose of this study was to examine whether the relationship between television and body mass index (BMI) is mediated by television snacking and junk food consumption.

METHODS

Results are based on 15,973 youth in grades 6-10 who participated in the Canadian 2009/2010 health behaviour in school-aged children survey (HBSC). Participants self-reported their weight and height and BMI z-scores were calculated based on World Health Organization growth standards. Participants reported the frequency of snacking while watching television and the frequency of eating junk food (sweets, soft drinks, baked goods, French fries, potato chips). Total hours per week of television were calculated. A contemporary multiple mediation analysis was used to examine associations.

RESULTS

A modest positive relationship was observed between television viewing and BMI. The mean BMI z-score was 0.15 units higher in youth in the highest television viewing quartile by comparison with the youth in the lowest quartile. However, contrary to our hypothesis, television snacking and junk food consumption were not significant positive mediators of the television and BMI relationship.

CONCLUSION

The pathways between television viewing and obesity are complicated and remain poorly understood. Future research using longitudinal or experimental designs, more precise measurement tools and formal mediation analyses is needed. This research should consider mediators related to both energy intake and expenditure.

Can sedentary behavior be made more active? A randomized pilot study of TV commercial stepping versus walking

Background

There is a growing problem of physical inactivity in America, and approximately a quarter of the population report being completely sedentary during their leisure time. In the U.S., TV viewing is the most common leisure-time activity. Stepping in place during TV commercials (TV Commercial Stepping) could increase physical activity. The purpose of this study was to examine the feasibility of incorporating physical activity (PA) into a traditionally sedentary activity, by comparing TV Commercial Stepping during 90 min/d of TV programming to traditional exercise (Walking).

Methods

A randomized controlled pilot study of the impact of 6 months of TV Commercial Stepping versus Walking 30 min/day in adults was conducted. 58 sedentary, overweight (body mass index 33.5 ± 4.8 kg/m²) adults (age 52.0 ± 8.6 y) were randomly assigned to one of two 6-mo behavioral PA programs: 1) TV Commercial Stepping; or 2) Walking 30 min/day. To help facilitate behavior changes participants received 6 monthly phone calls, attended monthly meetings for the first 3 months, and received monthly newsletters for the last 3 months. Using intent-to-treat analysis, changes in daily steps, TV viewing, diet, body weight, waist and hip circumference, and percent fat were compared at baseline, 3, and 6 mo. Data were collected in 2010–2011, and analyzed in 2011.

Results

Of the 58 subjects, 47 (81%) were retained for follow-up at the completion of the 6-mo program. From baseline to 6-mo, both groups significantly increased their daily steps [4611 ± 1553 steps/d vs. 7605 ± 2471 steps/d (TV Commercial Stepping); 4909 ± 1335 steps/d vs. 7865 ± 1939 steps/d (Walking); P < 0.05] with no significant difference between groups. TV viewing and dietary intake decreased significantly in both groups. Body weight did not change, but both groups had significant decreases in percent body fat (3-mo to 6-mo), and waist and hip circumference (baseline to 6-mo) over time.

Conclusions

Participants in both the TV Commercial Stepping and Walking groups had favorable changes in daily steps, TV viewing, diet, and anthropometrics. PA can be performed while viewing TV commercials and this may be a feasible alternative to traditional approaches for increasing daily steps in overweight and obese adults.

Trial Registration

This study is registered at ClinicalTrials.gov, NCT01342471

Sedentary behaviour and cardiovascular disease: a review of prospective studies

BACKGROUND

Current estimates from objective accelerometer data suggest that American adults are sedentary for ∼7.7 h/day. Historically, sedentary behaviour was conceptualized as one end of the physical activity spectrum but is increasingly being viewed as a behaviour distinct from physical activity.

METHODS

Prospective studies examining the associations between screen time (watching television, watching videos and using a computer) and sitting time and fatal and non-fatal cardiovascular disease (CVD) were identified. These prospective studies relied on self-reported sedentary behaviour.

RESULTS

The majority of prospective studies of screen time and sitting time has shown that greater sedentary time is associated with an increased risk of fatal and non-fatal CVD. Compared with the lowest levels of sedentary time, risk estimates ranged up to 1.68 for the highest level of sitting time and 2.25 for the highest level of screen time after adjustment for a series of covariates, including measures of physical activity. For six studies of screen time and CVD, the summary hazard ratio per 2-h increase was 1.17 (95% CI: 1.13-1.20). For two studies of sitting time, the summary hazard ratio per 2-h increase was 1.05 (95% CI: 1.01-1.09).

CONCLUSIONS

Future prospective studies using more objective measures of sedentary behaviour might prove helpful in quantifying better the risk between sedentary behaviour and CVD morbidity and mortality. This budding science may better shape future guideline development as well as clinical and public health interventions to reduce the amount of sedentary behaviour in modern societies.

Energy cost of stepping in place while watching television commercials

INTRODUCTION

Modifying sedentary television (TV) watching behaviors by stepping in place during commercials (TV commercial stepping) could increase physical activity and energy expenditure.

PURPOSE

The study's purpose was to determine the energy cost of TV commercial stepping and to quantify the amount of activity (number of steps and minutes) performed during 1 h of TV commercial stepping.

METHODS

In part 1, 23 adults (27.8 ± 7.0 yr) had their energy expenditure measured at rest, sitting, standing, stepping in place, and walking at 3.0 mph on the treadmill. The second part of this study involved 1 h of sedentary TV viewing and 1 h of TV commercial stepping. Actual steps were counted with a hand tally counter.

RESULTS

There were no differences (P = 0.76) between the caloric requirements of reclining rest (79 ± 16 kcal·h(-1)) and sedentary TV viewing (81 ± 19 kcal·h(-1)). However, stepping in place (258 ± 76 kcal·h(-1)), walking at 3.0 mph on the treadmill (304 ± 71 kcal·h(-1)), and 1 h of TV commercial stepping (148 ± 40 kcal·h(-1)) had a higher caloric requirement than either reclining rest or sedentary TV viewing (P < 0.001). One hour of TV commercial stepping resulted in an average of 25.2 ± 2.6 min of physical activity and 2111 ± 253 steps.

CONCLUSIONS

Stepping in place during commercials can increase the energy cost and amount of activity performed during TV viewing.

Sitting Behaviors and Mental Health among Workers and Nonworkers: The Role of Weight Status

Objective. To explore the associations between sitting time in various domains and mental health for workers and nonworkers and the role of weight status. Design. Cross-sectional analyses were performed for 1064 respondents (47% men, mean age 59 years) from the Doetinchem Cohort Study 2008-2009. Sedentary behavior was measured by self-reported time spent sitting during transport, leisure time, and at work. Mental health was assessed by the Mental Health Inventory (MHI-5). BMI was calculated based on measured body height and weight. Results. Neither sitting time during transport nor at work was associated with mental health. In the working population, sitting during leisure time, and particularly TV viewing, was associated with poorer mental health. BMI was an effect modifier in this association with significant positive associations for healthy-weight non-workers and obese workers. Conclusion. Both BMI and working status were effect modifiers in the relation between TV viewing and mental health. More longitudinal research is needed to confirm the results and to gain insight into the causality and the underlying mechanisms for the complex relationships among sedentary behaviors, BMI, working status, and mental health.

Prediction of body fat in older adults by time spent in sedentary behavior

The purpose of the study was to determine the relationship between sedentary behavior (SB), physical activity (PA), and body fat (total, abdominal) or body size (body-mass index [BMI], waist circumference [WC]) in community-dwelling adults 50 yr old and over. This study included 232 ambulatory adults (50-87 yr, 37.4% ± 9.6% body fat [BF]). Average daily time spent in SB (<100 counts/min) and light (100-759 counts/min), lifestyle-moderate (760-1,951 counts/min), walking-moderate (1,952-5,724 cts/min), and vigorous-intensity (≥ 5,725 counts/min) PA were determined by accelerometer and corrected for wear time. BF was measured with dual-energy X-ray absorptiometry. SB was positively related to measures of BF. Measures of SB, PA, and gender accounted for 55.6% of the variance in total BF, 32.4% of the variance in abdominal fat, and 28.0% of the variance in WC. SB, PA, and age accounted for 27.1% of the variance in BMI. Time spent in SB should be considered when designing obesity interventions for adults 50 yr old and over.

The relationship between media use and psychological and physical assets among third- to fifth-grade girls

BACKGROUND

Media use is associated with an increased risk of chronic disease and reduced quality of life among children. This study examined the relationship between media use during discretionary hours after school and psychological and physical assets among preadolescent girls.

METHODS

A cross-sectional analysis was conducted using data from a larger quasi-experimental evaluation of a positive youth development program through sport for third- to fifth-grade girls. Indicators of media use were the number of hours per school day spent watching television and videos and using computers. Psychological assets included global self-esteem, body size satisfaction, and commitment to physical activity; physical assets included physical activity. Nested random effects analysis of variance (ANOVA) models were used to examine the relationship between media use and psychological and physical assets controlling for relevant confounding factors.

RESULTS

The analytic sample included 1027 participants; most were ≥10 years old, non-White; 27% self-reported ≥4 hours of media use on school days. In adjusted results, media use was inversely associated with self-esteem (p = .008) and commitment to physical activity (p < .001). Time spent using media was not associated with body size satisfaction or physical activity in this age group.

CONCLUSIONS

Media use was negatively associated with self-esteem and commitment to physical activity. It may be useful for school professionals to encourage after-school programs that offer opportunities for girls to reduce sedentary pursuits and improve important psychological and physical assets.

Relationship of television time with accelerometer-derived sedentary time: NHANES

PURPOSE

To examine the relationship of self-reported television (TV) viewing time with accelerometer-derived total sedentary time and to determine whether it differs by subgroup.

METHODS

Using data for adults (≥20 yr) from the 2003-2004 and 2005-2006 nationally representative US National Health and Nutrition Examination Surveys (NHANES; n=5738), linear regression models examined the associations of categories of self-reported TV viewing time (<1, 1, 2, 3, 4, and >5 h·d) with accelerometer-derived sedentary time (<100 counts per minute; h·d). Spearman ρ assessed the correlation between participants' rankings on the two measures. Analyses were stratified by gender, age, race/ethnicity, and, in the 2003-2004 NHANES cycle, by work status among working-aged adults (20-65 yr, n=2069).

RESULTS

TV viewing time was significantly associated with sedentary time, with positive associations for all gender, age, race/ethnicity groups, and for those not working or working part-time, but not for those in full-time work. However, correlations between rankings of the measures were only "fair" overall (ρ=0.22) and were similar for all gender and racial/ethnic groups and for those of mid- and older age but not for those of younger age (20-39 yr, ρ=0.05). In the working-aged subgroup, there was also a fair correlation between the measures for those not working (ρ=0.22) but no significant correlation for those in part-time (ρ=0.14) or full-time work (ρ=0.03).

CONCLUSIONS

Associations of TV viewing time with accelerometer-derived total sedentary time were statistically significant, but correlations were of only fair magnitude, and the strength of the relationship was not consistent across all population subgroups. These findings suggest that TV viewing time has an influence on overall sedentary time at a population level; however, measurement of sedentary time in other domains is also important.

Sedentary behaviors and subsequent health outcomes in adults a systematic review of longitudinal studies, 1996-2011

CONTEXT

To systematically review and provide an informative synthesis of findings from longitudinal studies published since 1996 reporting on relationships between self-reported sedentary behavior and device-based measures of sedentary time with health-related outcomes in adults.

EVIDENCE ACQUISITION

Studies published between 1996 and January 2011 were identified by examining existing literature reviews and by systematic searches in Web of Science, MEDLINE, PubMed, and PsycINFO. English-written articles were selected according to study design, targeted behavior, and health outcome.

EVIDENCE SYNTHESIS

Forty-eight articles met the inclusion criteria; of these, 46 incorporated self-reported measures including total sitting time; TV viewing time only; TV viewing time and other screen-time behaviors; and TV viewing time plus other sedentary behaviors. Findings indicate a consistent relationship of self-reported sedentary behavior with mortality and with weight gain from childhood to the adult years. However, findings were mixed for associations with disease incidence, weight gain during adulthood, and cardiometabolic risk. Of the three studies that used device-based measures of sedentary time, one showed that markers of obesity predicted sedentary time, whereas inconclusive findings have been observed for markers of insulin resistance.

CONCLUSIONS

There is a growing body of evidence that sedentary behavior may be a distinct risk factor, independent of physical activity, for multiple adverse health outcomes in adults. Prospective studies using device-based measures are required to provide a clearer understanding of the impact of sedentary time on health outcomes.

Sedentary behavior and dietary intake in children, adolescents, and adults. A systematic review

CONTEXT

Sedentary behavior is implicated in youth and adult overweight and obesity. However, the relationship between sedentary behavior and weight status is often small or inconsistent, with few studies controlling for confounding factors such as diet and physical activity. Diet has been hypothesized to covary with some sedentary behaviors. It is opportune, therefore, to review whether dietary intake is associated with sedentary behavior in young people and adults. This may allow for better interpretation of the diversity of findings concerning sedentary behavior and weight status.

EVIDENCE ACQUISITION

Published English-language studies were located from computerized and manual searches in early 2010. Included studies were observational studies assessing an association between at least one sedentary behavior and at least one aspect of dietary intake in children (aged <11 years), adolescents (aged 12-18 years), or adults (aged >18 years).

EVIDENCE SYNTHESIS

Fifty-three studies, totaling 111 independent samples, were eligible for this review. Sedentary behavior in children (n=19, independent samples=24), adolescents (n=26, independent samples=72), and adults (n=11, independent samples=14) appears to be clearly associated with elements of a less healthy diet including lower fruit and vegetable consumption; higher consumption of energy-dense snacks, drinks, and fast foods; and higher total energy intake. Strengths of association were mainly in the small-to-moderate range.

CONCLUSIONS

The association drawn mainly from cross-sectional studies is that sedentary behavior, usually assessed as screen time and predominantly TV viewing, is associated with unhealthy dietary behaviors in children, adolescents, and adults. Interventions need to be developed that target reductions in sedentary time to test whether diet also changes.

Physical activity, television viewing time, and retinal microvascular caliber: the multi-ethnic study of atherosclerosis

Physical activities and sedentary behaviors are 2 broad classes of behavior that may be clearly distinguished from each other and have different patterns of determinants. The authors examined the associations of physical activity and television viewing time with retinal vascular caliber among US adults (n = 5,893) from 4 racial/ethnic groups in the Multi-Ethnic Study of Atherosclerosis (2002-2004) that included non-Hispanic whites, blacks, Hispanics, and Chinese. Physical activity and television viewing time were assessed by using a questionnaire, and vascular calibers (arteriolar and venular) were measured from digital retinal photographs. Those in the lowest quartile of physical activity had wider retinal venular caliber compared with those in the highest quartile in multivariate models adjusted for demographic, cardiovascular, behavioral, and inflammatory risk factors. This was noted in non-Hispanic whites and Hispanics but not in blacks or Chinese. For television viewing time, non-Hispanic whites (but not the other racial/ethnic groups) who were in the highest quartile of television viewing time had wider retinal venular caliber compared with those in the lowest quartile. No associations were noted with arteriolar caliber. Lower levels of physical activity (among non-Hispanic whites and Hispanics) and higher levels of television viewing time (among whites) are associated with wider retinal venules.

Sedentary behaviors and health outcomes among adults: a systematic review of prospective studies

CONTEXT

Nowadays, people spend a substantial amount of time per day on sedentary behaviors and it is likely that the time spent sedentary will continue to rise. To date, there is no review of prospective studies that systematically examined the relationship between diverse sedentary behaviors and various health outcomes among adults.

PURPOSE

This review aimed to systematically review the literature as to the relationship between sedentary behaviors and health outcomes considering the methodologic quality of the studies.

EVIDENCE ACQUISITION

In February 2010, a search for prospective studies was performed in diverse electronic databases. After inclusion, in 2010, the methodologic quality of each study was assessed. A best-evidence synthesis was applied to draw conclusions.

EVIDENCE SYNTHESIS

19 studies were included, of which 14 were of high methodologic quality. Based on inconsistency in findings among the studies and lack of high-quality prospective studies, insufficient evidence was concluded for body weight-related measures, CVD risk, and endometrial cancer. Further, moderate evidence for a positive relationship between the time spent sitting and the risk for type 2 diabetes was concluded. Based on three high-quality studies, there was no evidence for a relationship between sedentary behavior and mortality from cancer, but strong evidence for all-cause and CVD mortality.

CONCLUSIONS

Given the trend toward increased time in sedentary behaviors, additional prospective studies of high methodologic quality are recommended to clarify the causal relationships between sedentary behavior and health outcomes. Meanwhile, evidence to date suggests that interventions aimed at reducing sedentary behavior are needed.

Too much sitting: the population health science of sedentary behavior

Even when adults meet physical activity guidelines, sitting for prolonged periods can compromise metabolic health. Television (TV) time and objective measurement studies show deleterious associations, and breaking up sedentary time is beneficial. Sitting time, TV time, and time sitting in automobiles increase premature mortality risk. Further evidence from prospective studies, intervention trials, and population-based behavioral studies is required.

Age, affective experience, and television use

BACKGROUND

The reasons for the reportedly high levels of TV watching among older adults despite its potential negative health consequences are not known.

PURPOSE

To investigate age differences in time use and affective experience in TV use in a nationally representative sample.

METHODS

Using an innovative assessment of affective experience in a nationally representative sample, several putative reasons were examined for age-related increases in TV use. A sample of 3982 Americans aged 15-98 years who were assessed using a variant of the Day Reconstruction Method, a survey method for measuring how people experience their lives, was analyzed. To understand age increases in TV use, analyses examined whether older people (1) enjoy TV more; (2) watch TV because it is less stressful than alternatives; or whether (3) TV use was related to age differences in demographics, being alone, or life satisfaction. Data were collected in 2006 and analyzed in 2008-2009.

RESULTS

Adults aged >65 years spent threefold more waking time watching TV than young adults. Despite this trend, older people enjoyed TV less, in contrast to stable enjoyment with other leisure activities. Older adults did not seem to experience the same stress-buffering effects of watching TV as did young and middle-aged adults. This negative age-associated trend in how TV was experienced was not accounted for by demographic factors or in time spent alone. Greater TV use, but not time spent in other leisure activities, was related to lower life satisfaction.

CONCLUSIONS

Older adults watch more TV but enjoy it less than younger people. Awareness of this discrepancy could be useful for those developing interventions to promote reduced sedentary behaviors in older adults.