Screen time increases overweight and obesity risk among adolescents: a systematic review and dose-response meta-analysis

Study to Evaluate the Comparative Efficacy of Medhya Rasayana (Pharmacological) Versus Nonpharmacological Interventions in Management of Gadget Addiction in Children: Protocol for Parallel, Triple-Arm, Randomized Clinical Trial

BACKGROUND

Gadget addiction is a common behavioral problem among children. It is known to hamper social and academic life as well as adversely affect the lives of children. Ayurveda offers many therapeutic modalities and Ayurvedic medicines that can be used in the management of gadget addiction in children. The purpose of this study is to evaluate and compare the effectiveness of nonpharmacological therapies and the pharmaceutical intervention Medhya Rasayana in treating childhood gadget addiction.

OBJECTIVE

This study aims to provide a detailed description of the study methodology that will be used to compare the efficacy of nonpharmacological versus pharmaceutical interventions in the treatment of children's gadget addiction.

METHODS

A randomized, parallel, triple-arm interventional study will be conducted on diagnosed participants of gadget addiction with an age group of 6- to 16-year-old children, which will be selected and equally distributed in 2 groups. Group P will be given Medhya Rasayana (pharmacological intervention), group N will be nonpharmacological Ayurveda intervention, and group C (cognitive behavioral therapy) will be an external group. The Study duration is 180 days with assessment at baseline, midpoint, and endpoint Appropriate statistical techniques, such as ANOVA and regression analysis, will be used to examine the data and evaluate the efficacy of the 3 groups' interventions. We will perform subgroup analysis according to initial addiction severity, gender, and age. Primary outcome measures include a reduction in gadget addiction and changes in the psychosocial well-being of participants. Standardized questionnaires and instruments will be used to collect data.

RESULTS

In December 2023, the randomized controlled study got underway. Since participants may begin at any time, our goal is for everyone to be finished by December 2024.

CONCLUSIONS

This research will provide crucial new information about the relative effectiveness of Ayurveda nonpharmacological therapies and Medhya Rasayana in treating children's gadget addiction. The results will guide evidence-based treatments aimed at reducing the negative impact of excessive gadget use on this susceptible population's psychosocial development. In the end, the findings are meant to help policy makers and medical professionals create sensible plans to deal with the rising issue of childhood gadget addiction.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/51833.

Insomnia severity and obesity mediated by health behaviors in adolescents

OBJECTIVE

Sleep difficulties in youth have been associated with numerous negative outcomes, such as higher risk of obesity. Though the relationship between sleep and obesity is not well clarified, past research has shown that modifiable health behaviors, such as diet, physical activity, and screen time, may explain this relationship. The purpose of this study was to simultaneously examine these health behaviors as mediators of the relationship between insomnia severity and obesity among a sample of adolescents aged 12-18 years.

METHOD

English-speaking parents/legal guardians of adolescents were invited to participate in an online survey focused on pediatric sleep patterns, health behaviors, and weight. Parents/guardians (N = 599) reported on their adolescent's diet (i.e., consumption of fruits/vegetables, fast food, and breakfast), physical activity, screen time, and BMI. A multiple mediation analysis was run to test these health behaviors as mediators of the relationship between insomnia severity and BMI, after controlling for sex, age, race, and poverty.

RESULTS

While insomnia was related to most health behaviors, screen time was the only significant mediator of the relationship between insomnia and BMI, after controlling for the effects of the other mediators and all covariates, ab = .04, 95% CrI [.01, .09].

CONCLUSIONS

Screen time has implications for both adolescents' sleep health and weight. Pediatric clinicians should systematically assess for, and provide, recommendations on ways to improve sleep and screen time use, in addition to providing traditional dietary and physical activity recommendations.

Passive sensing of smartphone use, physical activity and sedentary behavior among adolescents and young adults during the COVID-19 pandemic

The research that links excessive screen time to adverse health outcomes is based on self-reported screen use. Few studies have documented how passively-sensed smartphone and app use relate to health behaviors like activity and sitting. Furthermore, they have not considered that daily fluctuations in smartphone/app use may have different relationships to these behaviors than a person's usual smartphone/app use. This study evaluated whether physical activity or sedentary (sitting) behavior are associated with either smartphone screen time or specific smartphone app use by adolescents and young adults during the COVID-19 pandemic. Adolescents and young adults aged 13-29 years wore activPAL4 micro activity monitors while their smartphones logged daily screen time and app use durations for nine days. Data were collected in 2020-2021 and analyzed in 2022-2023. Participants (N = 125) had a mean (SD) age of 19.7 (4.3) years. Participants' usual smartphone screen time was negatively associated with daily step counts. Daily deviations in smartphone screen time were negatively associated with daily step counts and moderate-vigorous physical activity durations. Time spent on Instagram, YouTube and, to a lesser extent, TikTok were linked with reduced activity levels. Daily sedentary behavior was not associated with usual or daily screen time. Interventions to promote physical activity during the transition into adulthood may benefit from limiting excessive smartphone screen time. Specific intervention targets could include limiting use of apps with infinite scrolling feeds algorithmically tuned to maintain user engagement, such as Instagram, YouTube and TikTok.

Socioeconomic Status and Obesity

Obesity is a pervasive public health problem that causes debilitating complications across the life course. One opportunity for preventing the onset of obesity is to focus on its social determinants. Socioeconomic status (SES), which includes factors such as income, educational attainment, occupational prestige, and access to resources, is a key determinant of obesity. In this scoping mini-review, we summarized review articles and meta-analyses of the SES-obesity association. From the 1980s to the present, cross-sectional studies have demonstrated a persistent socioeconomic gradient in obesity in which the association is negative in developed countries and positive in developing countries. Longitudinal studies have revealed the bidirectionality of the SES-obesity association; some studies demonstrate that socioeconomic adversity precedes the onset of obesity, while others provide evidence of reverse causality. While earlier studies relied on anthropometric assessments of weight and height to define obesity, the use of modern technologies like dual-energy x-ray absorptiometry and bioelectrical impedance have demonstrated that the socioeconomic gradient in obesity is robust across multiple indicators of body composition, including direct measures of lean and fat mass. More recently, examination of mediators and moderators of the SES-obesity association have highlighted causal pathways and potential intervention targets, with a focus on health behaviors, environmental conditions, psychological factors, and biological processes. We describe current gaps in knowledge and propose opportunities for future innovation to reduce the burden of obesity and related socioeconomic disparities.

The Overflow Effects of Movement Behaviour Change Interventions for Children and Adolescents: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

Considering the finite time within a 24-h day, the distribution of time spent on movement behaviours has been found to be associated with health outcomes.

OBJECTIVES

This systematic review and meta-analysis aimed to summarise and evaluate the overflow effects of interventions targeting a single behaviour (physical activity, sedentary behaviour/screen time, or sleep) on other non-targeted behaviours among children and adolescents.

METHODS

Six databases (MEDLINE [Ovid], PsycINFO [ProQuest], EMBASE [Ovid], PubMed, Web of Science and SPORTDiscus [EBSCO]) were searched for relevant studies published before 13 May, 2024. Randomised controlled trials and clustered randomised controlled trials that targeted a single behaviour and also assessed the effects on non-targeted behaviours, comprised of healthy children under the age of 18 years, were included. Movement behaviours can be measured either objectively or subjectively. The revised Cochrane risk-of-bias tool for randomised trials was adopted to evaluate the risk of bias.

RESULTS

A total of 102 studies with 45,998 participants from 21 countries were identified, and 60 of them with 26,183 participants were incorporated into the meta-analysis. The meta-analysis demonstrated that physical activity interventions led to a reduction in the proportion of each day spent in sedentary behaviour (mean difference =  - 0.95% of wear time, 95% confidence interval - 1.44, - 0.45, I2 = 39%). Sedentary behaviour interventions resulted in increased standing time (mean difference = 3.87%, 95% confidence interval 1.99, 5.75, I2 = 0%). Interventions targeting screen time did not yield changes in physical activity or sleep. The findings on the effectiveness of sleep interventions on non-targeted behaviours and of physical activity interventions on sleep were inconclusive.

CONCLUSIONS

Overall, the findings suggested that interventions aimed at increasing physical activity or reducing sedentary behaviour had overflow effects on non-targeted behaviours, but the effect sizes were small. Additional evidence is needed to reach definitive conclusions regarding the impact of behaviour change interventions on sleep and of the overflow effects of sleep interventions.

Prevalence of Overweight and Obesity and Their Associated Risk Factors in School-Going Children in North Karnataka City

Background Malnutrition presents threats to human health, including undernutrition and overweight. Obesity is becoming a worldwide problem affecting all levels of society. Therefore, it is described as a global epidemic with a more pronounced impact in developing countries undergoing rapid epidemiological transitions. An increase in the prevalence of childhood obesity is associated with potential medical complications of obesity in adulthood. The purpose of the study is to estimate the prevalence of obesity and risk factors associated with obesity in school-going children of north Karnataka city. Methods This cross-sectional study was conducted in schools in north Karnataka city on 1330 school-going children 10-17 years of age. The overweight and obesity groups were considered using an updated BMI reference of children from two to 18 years ago, according to the International Obesity Task Force (IOTF), and a structured questionnaire was used to assess the socio-demographic characteristics. Chi-square test was used to find out the association between risk factors and overweight and obesity and p value of less than 0.05 was deemed statistically significant. Results The prevalence of obesity in this study was 6.5%. It was found that 64 (22.9%) of the children who were obese or overweight were 14 years of age. Eighty (16.6%) obese children belonged to class 4 socio-economic class and 140 (22.0%) obese children used motorized means of transport. The eating habits of obese children were assessed, and it was found that 151 (19.4%) children had mixed diets, 210 (18.5%) obese children consumed junk food, and 183 (19.3%) obese children drank carbonated drinks. Conclusion This study suggest that the prevalence of overweight and obesity varies remarkably with different socio-demographic factors. Prevention of childhood obesity is necessary because it is nearly impossible to get children to lose weight and maintain it. Preventive interventions are needed at the individual level to adopt healthy lifestyle behavior and policy-making levels to tackle the obesity problem in the country.

Beyond Distracted Eating: Cognitive Distraction Downregulates Odor Pleasantness and Interacts with Weight Status

Considering the widespread issue of distracted eating, our study investigates how cognitive distraction influences the sensory perception of food-related odors among individuals with varying weight statuses. We conducted an exploratory, randomized, and cross-sectional experimental study, using the Tetris game to simulate real-life cognitive distraction, incorporating two distraction levels (low and high) and presenting five distinct odors. A total of 59 participants, categorized into a lean (n = 30) and overweight/obese group (n = 29) based on their body mass index (BMI), received odor stimuli while playing Tetris at low and high difficulty, corresponding to low and high distraction levels, respectively. Participants subsequently rated odor intensity and pleasantness under the two cognitive distraction conditions. Respiratory movements were monitored to ensure accurate olfactory stimulation. Our findings revealed no significant difference in odor intensity ratings across distraction levels (p = 0.903). However, there was a significant reduction in odor pleasantness under high cognitive distraction (p = 0.007), more pronounced in lean participants compared to those with an overweight status (p = 0.035). Additionally, an interaction between gender and cognitive distraction effects was observed in odor pleasantness perception. The differential effects of distraction across weight-status groups and genders are discussed in the context of hedonic motivation and compensatory mechanisms. This study sheds light onto the sensory mechanisms underlying distracted eating and could inform more personalized strategies for promoting healthier eating habits in a world dominated by distractions.

Cross-Sectional Assessment of Nutritional Status, Dietary Intake, and Physical Activity Levels in Children (6-9 Years) in Valencia (Spain) Using Nutrimetry

The aims of this research were to evaluate the current nutritional status, dietary intake, and level of physical activity and assess the need for intervention. This was a cross-sectional study with 2724 participating children aged 6-9 years old. Nutritional status was assessed using nutrimetry, dietary intake with a 3-day food-recall questionnaire and physical activity with an ad hoc questionnaire. The nutricode with the highest prevalence was healthy weight/normal stature, with 51.3% of the sample. For the BMI for age Z-score, those in the overweight/obesity category represented 37.5% of the sample, while the thinness category included 7.6%. Intake of calories, proteins, sugar, lipids, SFA, MUFA, and cholesterol were significantly higher than recommended. The thinness groups consumed a significantly higher amount of excess calories while the overweight/obesity groups had the lowest mean excess calorie intake. Children in the thinness category presented the highest rates at both ends of the spectrum for sedentary activities. This study showed the high prevalence of malnutrition in schoolchildren. The results for the risk of thinness and overweight/obesity according to individual nutrient intake should be carefully interpreted. Lifestyle is a fundamental aspect to consider when combating malnutrition, especially at the level of dietary and physical activity habits, to combine various methods of intervention to improve nutritional status.

Effects of outdoor activity time, screen time, and family socioeconomic status on physical health of preschool children

Objective

Experienced 3 years of pandemic-induced home life, in the post-epidemic period, preschoolers in China are falling short of the World Health Organization's standards for screen time and outdoor activities. This notably impacts their physical well-being. The study aims to probe the associations between screen time, outdoor activities, and the physical health of preschoolers, offering insights to shape interventions targeting myopia and obesity prevention in children.

Methods

A cross-sectional study was conducted in Guangdong Province, involving a representative sample of 23,992 preschoolers and their caregivers recruited through proportional stratified cluster sampling. Data collection utilized the Chinese Early Human Capability Index (CHeHCI, eHCi), a questionnaire on children's media use in daily family life, and Body Mass Index (BMI). Linear regression and binary logistic regression models were employed to analyze the impact of screen time and outdoor activity duration on the physical health of preschoolers.

Results

In the high family socioeconomic status (SES) group, children had significantly less screen time compared to those in the medium and low SES groups. Outdoor activity time varied significantly based on SES, with higher SES linked to extended outdoor engagement. Additionally, children's eHCi health dimension score exhibited significant SES-related differences, showcasing higher scores for children in higher SES groups. In terms of gender differences, boys dedicated significantly more time to outdoor activities than girls, yet boys had a notably higher overweight rate. Furthermore, girls demonstrated better health outcomes based on eHCi health scores. A significant association emerged between overweight and screen time in children with high SES, indicating that prolonged screen time was linked to a higher likelihood of overweight based on BMI. Additionally, a substantial negative correlation was observed between children's eHCi health dimension score and screen time. Furthermore, children's outdoor activity time exhibited a significant positive correlation with eHCi health dimension score. Regression analysis revealed that screen time could significantly negatively predict children's physical health score, while outdoor activity time could significantly positively predict children's eHCi physical health score.

Conclusion

The current study highlights that family SES, age, and gender play pivotal roles in influencing preschoolers' screen time and outdoor activity duration, with family SES being particularly influential. Higher family SES correlates with reduced screen time, increased outdoor activity, and elevated health levels among children. Importantly, children's screen time negatively predicts their health status, while outdoor time positively predicts their health status.

The impact of family factors and communication on recreational sedentary screen time among primary school-aged children: a cross-sectional study

BACKGROUND

Childhood obesity is increasingly recognized as a major public health challenge worldwide, and excessive sedentary screen time is emerging as a key risk factor. This study aimed to assess the recreational screen sedentary time of Chinese primary school-aged children and investigate the relationship between screen-related family factors and the outcome variable.

METHODS

Our study used data from a cross-sectional survey collected from fifth-grade students and their parents in Beijing, China, from April to May 2018 (n = 2,373). The questions included basic demographic information, family socioeconomic status, students' and parents' sedentary and exercising habits, within-family communicational factors, and health belief patterns. The recreational screen sedentary time of the children was compared across demographic groups. The study employed multivariate linear regression models to examine associations between children's screen time and various family factors, as well as the moderating effect of overall family communication.

RESULTS

Our findings revealed an average daily recreational screen sedentary time of 2.4 h among participants. Screen time significantly varied across demographic categories, including children's sex, age, residence, parents' education, household income, family size, and primary family member. After adjustment, the proportion of child-owned digital devices (p < 0.01), child's personal room (p < 0.05), family screen-viewing together (p < 0.01), and parental screen time (p < 0.01) were positively related to children's recreational sedentary screen time. Parental restrictions on screen time (p < 0.001) and attitudes toward reducing sitting time (p < 0.01) were correlated with a decrease in children's screen time. The overall family communication environment significantly moderated the effects of parental practice of restricting children's screen time (p < 0.001), positive reinforcement by parents (p < 0.05), and parents' recreational sedentary screen time (p < 0.001).

CONCLUSIONS

Our findings underscored the significance of family dynamics, parental practices, and communication in shaping children's screen time behaviors, providing valuable insights for tailored interventions and strategies to reduce childhood obesity.

Understanding health behaviors that modify the risk for obesity in ADHD

OBJECTIVE

Research provides support for the associated risk of inadequate sleep duration, limited physical activity, and excessive media use in attention-deficit/hyperactivity disorder (ADHD) and obesity. The present study aims to (1) examine the association between ADHD and overweight or obese status (OW/OB); (2) comprehensively examine sleep duration, physical activity, and media use as potential moderators of OW/OB; and (3) examine the moderating effects of these health behaviors cross-sectionally by comparing medicated youth with ADHD, unmedicated youth with ADHD, and youth without ADHD.

METHODS

Data were acquired from the 2018 and 2019 National Survey of Children's Health, a nationally representative survey of caregivers conducted across the United States. The current study used data for youth 11-17 years old with a final sample size of 26,644. Hours of sleep, physical activity, and media use per day were dichotomized based on national recommendation guidelines for each health behavior (i.e., either meeting or not meeting guidelines).

RESULTS

The OW/OB prevalence rate was 7% greater among unmedicated youth with ADHD than among medicated youth with ADHD. Medicated youth with ADHD and peers without ADHD had similar OW/OB rates. Among medicated youth with ADHD, physical activity, sleep duration, and media use did not contribute to OW/OB risk after controlling for family poverty level. However, among unmedicated youth with ADHD, meeting sleep duration guidelines was linked to a lower OW/OB risk.

CONCLUSION

Overall, findings suggest that clinical providers and parents may wish to prioritize improved sleep duration in the management of OW/OB risk in youth with ADHD.

Combined effects of sugar-sweetened beverage consumption, screen-based sedentary behavior, and sleep duration on South Korean adolescent obesity: a cross-sectional study

PURPOSE

This study examined the combined effects of sugar-sweetened beverage (SSB) consumption, screen-based sedentary behaviors, and sleep duration on adolescent obesity.

METHODS

It followed a cross-sectional study design and conducted secondary analysis on data from 20,497 high school students who participated in the 17th (2021) Korea Youth Risk Behavior Web-based Survey. This study underwent logistic regression analysis in complex sampling analysis.

RESULTS

The combinations of low and medium consumption of SSBs, excessive screen-based sedentary behaviors, and short sleep durations were associated with a 1.18 and 1.12 fold increased likelihood of obesity (95% confidence interval [CI]=1.03-1.35) and (95% CI=1.02-1.22), respectively. The combination of high SSB consumption, appropriate screen-based sedentary behaviors, and short sleep duration (adjusted odds ratio [aOR]=1.15, 95% CI=1.01-1.31) and high SSB consumption, excessive screen-based sedentary behaviors, and short sleep duration (aOR=1.40, 95% CI=1.16-1.69) were associated with obesity.

CONCLUSION

Integrated and tailored programs considering combination patterns of SSB consumption, screen-based sedentary behaviors, and short sleep duration need to be developed for preventing adolescent obesity.

An umbrella review of the benefits and risks associated with youths' interactions with electronic screens

The influence of electronic screens on the health of children and adolescents and their education is not well understood. In this prospectively registered umbrella review (PROSPERO identifier CRD42017076051 ), we harmonized effects from 102 meta-analyses (2,451 primary studies; 1,937,501 participants) of screen time and outcomes. In total, 43 effects from 32 meta-analyses met our criteria for statistical certainty. Meta-analyses of associations between screen use and outcomes showed small-to-moderate effects (range: r = -0.14 to 0.33). In education, results were mixed; for example, screen use was negatively associated with literacy (r = -0.14, 95% confidence interval (CI) = -0.20 to -0.09, P ≤ 0.001, k = 38, N = 18,318), but this effect was positive when parents watched with their children (r = 0.15, 95% CI = 0.02 to 0.28, P = 0.028, k = 12, N = 6,083). In health, we found evidence for several small negative associations; for example, social media was associated with depression (r = 0.12, 95% CI = 0.05 to 0.19, P ≤ 0.001, k = 12, N = 93,740). Limitations of our review include the limited number of studies for each outcome, medium-to-high risk of bias in 95 out of 102 included meta-analyses and high heterogeneity (17 out of 22 in education and 20 out of 21 in health with I2 > 50%). We recommend that caregivers and policymakers carefully weigh the evidence for potential harms and benefits of specific types of screen use.

Psychosocial and environmental risk factors of obesity and hypertension in children and adolescents-a literature overview

Childhood obesity has become a worldwide epidemic in the 21st century. Its treatment is challenging and often ineffective, among others due to complex, often not obvious causes. Awareness of the existence and meaning of psychosocial and environmental risk factors seems to be an essential element in the prevention and treatment of obesity and its complications, especially arterial hypertension. In this review, we will discuss the role of that risk factors linking obesity and increased cardiovascular disorders including the role of nutritional factors (including the role of unhealthy diet, inadequate hydration), unhealthy behaviors (e.g. smoking, alcohol and drugs, sedentary behavior, low physical activity, disrupted circadian rhythms, sleep disorders, screen exposure), unfavorable social factors (such as dysfunctional family, bullying, chronic stress, mood disorders, depression, urbanization, noise, and environmental pollution), and finally differences in cardiovascular risk in girls and boys.

Changes in the prevalence of obesity in Czech adolescents between 2018 and 2022 and its current non-genetic correlates - HBSC study

BACKGROUND

The main aim of the study is to examine changes in the prevalence of obesity in Czech adolescents between 2018 and 2022 and its current non-genetic correlates with respect to the adolescents' families'socioeconomic status (SES) in 2022.

METHODS

The sample of 24,535 adolescents (n = 11,629/12,9062018/2022; boys: 50.4/50.6%2018/2022) aged 10.5-16.5 years that was analysed was drawn from two nationally representative cohorts of Czech youngsters from the last two cycles of the Health Behaviour in School-aged Children (HBSC) online questionnaire survey from 2018 to 2022. Obesity is represented by the > 97th percentile interval on the World Health Organization Body Mass Index percentile chart, with distinctions by sex and the age of adolescents. The differences in the prevalence of obesity between boys and girls from all SES family categories in 2018 and 2022 were tested using a chi-square test (χ2). Multiple logistic regression analysis with repeated measures was used to analyse correlates of obesity in 2022.

RESULTS

Between 2018 and 2022, there was no significant difference in the prevalence of obesity in girls or boys in any of the SES categories of families. Adolescents from low-SES families have the highest prevalence of obesity, 11% for boys and 5.8% for girls, significantly higher (p < .001) than its prevalence among adolescents from high-SES families, by + 4.8% points for boys and + 3.9% points for girls. Among adolescents from low-SES families, individuals who engaged in moderate-to-vigorous physical activity (PA) daily (p < .005) or vigorous PA three times per week (p < .05) were significantly less likely to be obese than their less active peers. Skipping breakfast significantly (p < .05) increased the odds of obesity, but only among adolescents from low-SES families. Shorter screen time (ST) significantly (p < .05) reduced the odds of obesity for all categories of adolescent SES.

CONCLUSIONS

Obesity is most pronounced in adolescents from low-SES families as a result of a long-term positive energy balance mediated by unbalanced behaviour. Significantly lower odds of obesity in adolescents from low-SES families were confirmed to be associated with regular practice of the recommended PA, shorter ST, and not skipping breakfast.

Screen Time and Its Health Consequences in Children and Adolescents

Nowadays, children and adolescents are exposed to digital media (DM) from an early age. Therefore, specific guidelines have been published by the World Health Organization, whose aim is to limit daily screen time (ST) viewing. However, during the COVID-19 pandemic, a rise in DM use, and consequently ST viewing, was observed. More and more aspects of modern life are thought to be affected by excessive ST viewing. Accordingly, the aim of this review is to document the health effects of excessive ST viewing on children and adolescents. A narrative review was performed in searchable databases. In total, 43 original articles were considered. Excessive ST viewing was correlated with increased risk for obesity and other cardiometabolic risk factors, mental health, unhealthy dietary habits and eating disorders, and problems in development and child-parent relationships. Sleep, physical activity, eyesight, headaches, and the musculoskeletal system were negatively affected as well. However, the effect of ST was weighted by the type of media used and the way types of media were used. Other confounding factors were reported. There is evidence to suggest a negative correlation between excessive ST and youth health exists. Nevertheless, more research is needed if this correlation is to be established.

The causal effects of leisure screen time on irritable bowel syndrome risk from a Mendelian randomization study

Associations between leisure sedentary behavior (especially leisure screen time, LST) and irritable bowel syndrome (IBS) have been reported, but causality is unclear. Here, the two-sample Mendelian randomization was performed to investigate the causal association between LST and IBS. Two recently published genome-wide association studies (GWASs) including a total of 1,190,502 people from Europe were used as our data source. Inverse variance weighting (OR = 1.120, 95% CI 1.029-1.219) and weighted median (OR = 1.112, 95% CI 1.000-1.236) analyses revealed a causal effect between LST and IBS. There was no evidence of pleiotropy in the sensitive analysis (MR-Egger, p = 0.139). After removing potentially confounding single nucleotide polymorphisms (SNPs), similar results were found using inverse variance weighting (OR = 1.131, 95% CI 1.025-1.248) and weighted median (OR = 1.151, 95% CI 1.020-1.299), as well as in the validation analyses using inverse variance weighting (OR = 1.287, 95% CI 0.996-1.662). This study provided support for a possible causal relationship between leisure screen time and IBS.

Association between duration of electronic screen use for non-educational purposes and depression symptoms among middle and high school students: a cross-sectional study in Zhejiang Province, China

Background

Existing literature on the association of electronic screen use duration with depression among adolescents is contradictory. The current study aimed to elucidate the association between duration of electronic screen use for non-educational purposes and depression symptoms among middle and high school students in Zhejiang Province, China.

Methods

A cross-sectional study of 27,070 students in grades 7-12 from 376 middle and high schools was conducted through an anonymous self-administered questionnaire between April and June 2022. Poisson regression was utilized to examine the association between electronic screen use duration for non-educational purposes and depression symptoms.

Results

Of the 27,006 eligible students, 51.6% (13932) were boys and the mean (SD) age was 15.6(1.7) years. The overall prevalence of symptoms of depression was 22.4% (95%CI 21.4-23.4); girls (27.6%, 26.2-29.0) had a higher prevalence than boys (17.7%, 16.7-18.8). After adjustment for socio-demographic status, lifestyle factors, self-perceived health, academic performance, loneliness and sadness, compared to those who did not use electronic screens for non-educational purposes, the prevalence ratios (PRs) for depression symptoms were 1.03 (95% CI 1.02-1.04) for those exposed to electronic screens for <1 h/day, 1.07 (1.05-1.09) for 1.0-1.9 h/day, 1.10 (1.07-1.13) for 2.0-2.9 h/day, 1.14 (1.10-1.18) for 3.0-3.9 h/day, 1.18 (1.12-1.23) for 4.0-4.9 h/day, and 1.21 (1.15-1.29) for ≥5 h/day.

Conclusion

Duration of electronic screen use for non-educational purposes was positively associated with symptoms of depression among middle and high school students, even with a relatively short daily duration of use.

Toward an Integrated Consideration of 24 h Movement Guidelines and Nutritional Recommendations

While physical activity, sleep and sedentary behaviors are almost always considered independently, they should be considered as integrated human behaviors. The 24 h Movement approach proposes a concomitant consideration of these behaviors to promote overall health. Not only do these behaviors impact energy expenditure, but they have also been shown to separately impact energy intake, which should be further explored when considering the entire integration of these movement behaviors under the 24 h movement approach. After an evaluation of the prevalence of meeting the 24 h Movement and dietary recommendations, this review summarizes the available evidence (using English publications indexed in PubMed/MEDLINE) regarding the association between the 24 h Movement Guidelines and eating habits. Altogether, the results clearly show the beneficial impact of promoting the 24 h guidelines simultaneously, highlighting that the higher the number of respected movement recommendations, the better eating behaviors in both children and adults. Importantly, our results point out the importance of emphasizing the need to reach sedentary guidelines for better eating habits. Movement and dietary behaviors appear closely related, and giving recommendations on one might impact the other. Combining the 24 h Movement with dietary Guidelines might be more efficient than promoting them separately in public health strategies.

The Complex Effects of Light on Metabolism in Humans

Light is an essential part of many life forms. The natural light–dark cycle has been the dominant stimulus for circadian rhythms throughout human evolution. Artificial light has restructured human activity and provided opportunities to extend the day without reliance on natural day–night cycles. The increase in light exposure at unwanted times or a reduced dynamic range of light between the daytime and nighttime has introduced negative consequences for human health. Light exposure is closely linked to sleep–wake regulation, activity and eating patterns, body temperature, and energy metabolism. Disruptions to these areas due to light are linked to metabolic abnormalities such as an increased risk of obesity and diabetes. Research has revealed that various properties of light influence metabolism. This review will highlight the complex role of light in human physiology, with a specific emphasis on metabolic regulation from the perspective of four main properties of light (intensity, duration, timing of exposure, and wavelength). We also discuss the potential influence of the key circadian hormone melatonin on sleep and metabolic physiology. We explore the relationship between light and metabolism through circadian physiology in various populations to understand the optimal use of light to mitigate short and long-term health consequences.

Relationship between Behavioural Intention for Using Food Mobile Applications and Obesity and Overweight among Adolescent Girls

Changes in the body mass index (BMI) of children and adolescents have been linked to mobile usage, particularly food applications. This study aimed to investigate the relationship between food application usage and obesity and overweight among adolescent girls. This cross-sectional study was conducted among adolescent girls aged 16-18 years. Data were collected using a self-administered questionnaire from female high schools in five different regional offices across Riyadh City. The questionnaire included questions regarding demographic data (age and academic level), BMI and behavioural intention (BI) scale comprising three constructs: attitude towards behaviour, subjective norms and perceived behavioural control. Of the included 385 adolescent girls, 36.1% were 17 years old, and 71.4% had normal BMI. The overall mean BI scale score was 65.4 (SD 9.95). No significant differences were observed between overweight or obesity in relation to the overall BI score and its constructs. A high BI score was more associated with participants studying in the east educational office than those who were enrolled in the central educational office. Behavioural intention to use food applications greatly influenced the adolescent age group. Further investigations are necessary to determine the influence of food application services among individuals with high BMI.

Childhood obesity risk increases with increased screen time: a systematic review and dose-response meta-analysis

BACKGROUND

The role of screen time in promoting obesity among children has been reported in previous studies. However, the effects of different screen types and the dose-response association between screen time and obesity among children is not summarized yet. In the current meta-analysis we systematically summarized the association between obesity and screen time of different screen types in a dose-response analysis.

METHODS

A systematic search from Scopus, PubMed and Embase electronic databases was performed. Studies that evaluated the association between screen time and obesity up to September 2021 were retrieved. We included 45 individual studies that were drawn from nine qualified studies into meta-analysis.

RESULTS

The results of the two-class meta-analysis showed that those at the highest category of screen time were 1.2 times more likely to develop obesity [odds ratio (OR) = 1.21; confidence interval (CI) = 1.113, 1.317; I2 = 60.4%; P < 0.001). The results of subgrouping identified that setting, obesity status and age group were possible heterogeneity sources. No evidence of non-linear association between increased screen time and obesity risk among children was observed (P-nonlinearity = 0.310).

CONCLUSION

In the current systematic review and meta-analysis we revealed a positive association between screen time and obesity among children without any evidence of non-linear association. Due to the cross-sectional design of included studies, we suggest further studies with longitudinal or interventional design to better elucidate the observed associations.

Association Between Time Spent on Electronic Devices and Body Mass Index in Young Adults

Objective

To evaluate the association between time spent on electronic devices (TSED) and body mass index in young adults.

Methods

This cross-sectional study was conducted from June to December 2021 on 1877 students (aged 18–22 yrs) from multiple health Colleges of Imam Abdulrahman Bin Faisal University. The main tools of the study were 1) Body mass index (BMI) and an online questionnaire. The subjects were categorized into 3 main groups based on their TSED: 1) Low TSED < 2 hours/day, 2) Medium TSED= 3 to 5 hours/day, 3) Excessive TSED ≥ 6 hours /day. Based on BMI, subjects were categorized into three main groups: Normal and underweight (BMI ≤ 24.9), overweight (BMI > 25–29.9), and obese (BMI > 30).

Results

Participants’ average age was 20 ± 2 years. The average BMI was 23.5 k/m². The % of students falling into the categories of normal weight, overweight, and obesity was 69.2%, 19.05%, and 11.7% respectively. The average TSED of study participants was 8.2 ± 3.45 hrs /24 hours. 71.15% of participants indicated a TSED of ≥6 hrs/24 hours and 23.71% reported a TSED of 3–5 hrs/24 hours. Only 3.15% of participants reported TSED of ≤2 hrs/24 hours. Although a rise in the mean BMI was observed with an increase in the TSED, but this difference was not statistically significant. The pairwise wise comparison also failed to demonstrate any difference in BMI between different categories of TSED. Furthermore, no significant positive correlation was found between increased BMI and excessive TSED (P = 0.37).

Conclusion

A high percentage of young adults (31.2%) were overweight or obese, but excessive TSED was not significantly associated with increased BMI in this study population. Further studies are recommended to identify the effects of other factors in causing increased BMI in young adults.