Association of eating while television viewing and overweight/obesity among children and adolescents: a systematic review and meta‐analysis of observational studies

The objective of this systematic review and meta‐analysis was to examine the association between eating while television viewing (TVV) and overweight or obesity in children (<18 years). A systematic search of PubMed, Scopus, Web of science, PreQuest and Embase was conducted up to April 2017; pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated using a random effects model. Of 4,357 articles identified, 20 observational studies met inclusion criteria (n = 84,825) and 8 of these 20 (n = 41,617) reported OR. Eating while TVV was positively associated with obesity‐related anthropometric measurements in 15 studies (75%). The meta‐analysis revealed that eating while TVV was positively associated with being overweight (OR = 1.28; 95% CI: 1.17, 1.39). Subgroup analyses showed similar positive associations in both girls and boys, as well as in children who ate dinner while TVV. There was no evidence of publication bias. The present systematic review and meta‐analysis suggests that eating while TVV could be a risk factor for being overweight or obese in childhood and adolescents.     

Prevalence of overweight among children in Europe

Estimates of the prevalence of childhood overweight and obesity have been made in several European countries during the last decade. The methods used and the assessment criteria differ from survey to survey. The present paper reports the prevalence data from 21 surveys in Europe using a single, internationally accepted definition of overweight in childhood, allowing direct comparisons to be made. A tendency for a higher prevalence of overweight among children in western and especially southern Europe is shown and some possible reasons for this are discussed.     

Global benchmarking of children's exposure to television advertising of unhealthy foods and beverages across 22 countries

Restricting children's exposures to marketing of unhealthy foods and beverages is a global obesity prevention priority. Monitoring marketing exposures supports informed policymaking. This study presents a global overview of children's television advertising exposure to healthy and unhealthy products. Twenty‐two countries contributed data, captured between 2008 and 2017. Advertisements were coded for the nature of foods and beverages, using the 2015 World Health Organization (WHO) Europe Nutrient Profile Model (should be permitted/not‐permitted to be advertised). Peak viewing times were defined as the top five hour timeslots for children. On average, there were four times more advertisements for foods/beverages that should not be permitted than for permitted foods/beverages. The frequency of food/beverages advertisements that should not be permitted per hour was higher during peak viewing times compared with other times (P < 0.001). During peak viewing times, food and beverage advertisements that should not be permitted were higher in countries with industry self‐regulatory programmes for responsible advertising compared with countries with no policies. Globally, children are exposed to a large volume of television advertisements for unhealthy foods and beverages, despite the implementation of food industry programmes. Governments should enact regulation to protect children from television advertising of unhealthy products that undermine their health.     

Childhood overweight: a contextual model and recommendations for future research

The prevalence of overweight among children has doubled within the past two decades. Increases in the rate of childhood overweight are of particular concern due to the negative health and psychological effects noted among overweight children. As shown by previous research, the development of childhood overweight involves a complex set of factors from multiple contexts that interact with each other to place a child at risk of overweight. This multifaceted system can be conceptualized using Ecological Systems Theory (EST). EST highlights the importance of considering the context(s), or ecological niche, in which a person is located in order to understand the emergence of a particular characteristic. In the case of a child, the ecological niche includes the family and the school, which are in turn embedded in larger social contexts including the community and society at large. In this review, EST is used as a framework with which to summarize research assessing predictors of childhood overweight. Specifically, child characteristics that place children at risk of the development of overweight (including dietary intake, physical activity, and sedentary behaviour) will be reviewed while taking into consideration the influence of the familial environment, the school environment, and the community and larger social environments. It is concluded that future research needs to adopt a broader contextual approach in order to understand and intervene against the processes leading to the development of overweight among children and that the use of theories or paradigms such as EST will facilitate developing and testing models of causal processes.     

Developmental coordination disorder and overweight and obesity in children: a systematic review

Children with developmental coordination disorder (DCD) find themselves less competent than typically developing children with regard to their physical abilities and often experience failure. They are therefore likely to avoid physical activity. Physical inactivity is considered an important risk factor for developing overweight and obesity. The aim of this study is to assess the association between DCD and overweight and obesity in children and whether this association is influenced by age and/or gender. Six electronic databases were systematically searched. Titles and abstracts were screened for relevance. Remaining studies were subjected to full paper review. The quality of the included articles was assessed and relevant data were extracted for comparison. The search yielded 273 results. Twenty‐one studies, based on 10 cohorts, were included. Participants' ages ranged from 4 to 14 years. In all cohorts, children with DCD had higher body mass index scores, larger waist circumference and greater percentage body fat compared with controls. Seven studies assessed the effect of gender and four studies provided information on the effect of age. Children with DCD seem to be at greater risk for overweight and obesity. This risk may be higher for boys and seems to increase with age and with the severity of motor impairment.     

A national survey of the prevalence of childhood overweight and obesity in Italy

To estimate the prevalence of childhood overweight and obesity among Italian schoolchildren and to examine geographic differences and present and future implications for health care, we used data from a nationwide representative survey performed in May 2008 among third-grade students in 18 of Italy's 21 regions. Cluster sampling was used to identify classes for participation. The study population included all children aged 8–9 years whose parents agreed to opt-out consent. Parents, children and teachers completed brief questionnaires, and children were weighed and measured by trained staff using standardized equipment. Consent was obtained for 97% of 50 197 third-graders, of whom 44 676 (89%) met study inclusion criteria. Obesity levels (defined using International Obesity Task Force cut-offs) ranged from 7.5% (95% confidence intervals 6.7–8.2) in the north to 16.6% (95% confidence intervals 15.8–17.4) in the south. Behaviours known to be associated with obesity also showed geographic differences. The estimated burden of obesity-related pathologies also increased from north to south. These findings suggest the need for community as well as individual interventions in all areas of the country but with particular attention to the south.     

The impact of school-based prevention of overweight on psychosocial well-being of children

This review aimed to gain insight in the extent to which psychosocial effects of obesity prevention programmes have been studied, to give an overview of the methods used to measure the particular psychosocial aspects and – if possible – to quantify the effects found. Intervention studies ( n  = 267) covering the period 1990–October 2005 were derived from seven reviews about childhood obesity interventions. An additional search identified 2754 studies covering the period January 2005–February 2008. In total, 2901 papers (excluding 120 duplicates) were screened for inclusion. Sixty-nine papers covering 53 interventions were included and screened on measuring psychosocial variables. All original authors were contacted. Seven of the selected interventions measured psychosocial variables, five of which evaluated a net intervention effect as compared with a control condition. Only two interventions reported a statistically significant net intervention effect (a decrease in use of purging or diet pills and a decrease in peer ratings of aggression and observed verbal aggression). We conclude that a minority of childhood obesity interventions investigate the effects of their programmes on psychosocial well-being of children and adolescents. It is recommended that in the future, these programmes will be evaluated in a uniform way on a broad range of psychosocial aspects     

The association between childcare arrangements and risk of overweight and obesity in childhood: a systematic review

Over 80% of preschool‐aged children experience non‐parental childcare. Childcare type has the potential to influence weight outcomes, but its impact on childhood overweight/obesity is not well established. This review aims to (i) systematically evaluate the effects of childcare type on childhood overweight/obesity risk and (ii) investigate the impact of childcare intensity and age at commencement. Five electronic databases were searched for observational studies quantifying an association between childcare type ≤5 years and weight outcomes <18 years. Twenty‐four studies were included (n = 127,529 children). Thirteen studies reported increased risk of overweight/obesity in children attending informal care (n = 9) or centre care (n = 4) vs. parental care. Seven studies reported decreased risk of overweight/obesity for children in centre vs. ‘non‐centre’ care (parental and informal). Four studies reported no association between informal or centre care and overweight/obesity. Early (<3 years) informal care, especially by a relative, was associated with increased risk of overweight/obesity. Higher intensity childcare, especially when commenced early (<1 year), increased overweight/obesity risk. Later (≥3 years) centre care was associated with decreased risk of overweight/obesity. Early informal care, earlier commencement age and higher intensity represent a risk for childhood obesity. Exploration of the obesogenic aspects of these contexts is essential to inform preventative measures.     

Relationship between costs of lifestyle interventions and weight loss in overweight adults

Lifestyle interventions in a healthcare setting are effective for weight loss, but it is unclear whether more expensive interventions result in more weight loss. Our objective was to explore the relationship between intervention costs and effectiveness in a systematic review of randomized trials.
Intervention studies were selected from 14 reviews and from a systematic MEDLINE-search. Studies had to contain a dietary and a physical activity component and report data on measured weight loss in healthy Caucasian overweight adults. Intervention costs were calculated in a standardized way. The association between costs and percentage weight loss after 1 year was assessed using regression analysis.
Nineteen original studies describing 31 interventions were selected. The relationship between weight loss and intervention costs was best described by an asymptotic regression model, which explained 47% of the variance in weight loss. A clinically relevant weight loss of 5% was already observed in interventions of approximately €110. Results were similar in an intention-to-treat analysis.
In conclusion, lifestyle interventions in health care for overweight adults are relatively cheap and higher intervention costs are associated with more weight loss, although the effect of costs on weight loss levels off with growing costs.     

Evidence for a link between IGF-I and cancer

Cancer risk is determined by a combination of environmental factors and genetic predisposition. Recent evidence suggests that dietary and related factors such as physical activity and body size may influence cancer risk through their effects on the serum concentration of IGF-I and its binding proteins. The growth hormone (GH)/IGF-I axis is involved in both human development as well as the maintenance of normal function and homeostasis in most cells of the body. In addition to their classical role as endocrine hormones, its members regulate a wide range of biological functions such as cell proliferation, differentiation and apoptosis through paracrine and autocrine mechanisms. During cancer development this complex network regulating tissue homeostasis breaks down, with inappropriate expression of the GH/IGF-I axis making an important contribution. The increased understanding of the molecular mechanisms and signalling pathways regulated by the GH/IGF-I axis has started to provide significant insights into the aetiology, prevention and therapy for a number of common cancers.     

Association between overweight/obesity and periodontitis in adults. A systematic review

Overweight and obesity have been suggested to be associated with periodontitis as published in studies and narrative summaries. This project presents results of a systematic review investigating the association between overweight or obesity (as defined by the World Health Organization) and periodontitis. Search strategy included electronic and hand searching to December 2009. Ovid MEDLINE, EMBASE, LILACS, and SIGLE were searched. RCTs, cohort, case–control and cross‐sectional study designs that included measures of periodontitis and body composition were eligible. Duplicate, independent screening and data abstraction were performed. Meta‐analyses were performed when appropriate. A total of 526 titles and abstracts were screened, resulting in 61 full text articles and abstracts assessed for eligibility with 33 being included. Nineteen studies provided sufficient information for inclusion in meta‐analyses. Meta‐analyses indicated statistically significant associations between periodontitis and body mass index (BMI) category obese OR 1.81(1.42, 2.30), overweight OR 1.27(1.06, 1.51) and obese and overweight combined OR 2.13(1.40, 3.26). In conclusion, these results support an association between BMI overweight and obesity and periodontitis although the magnitude is unclear. Additional prospective studies to further quantify, or understand the mechanisms, of this association are merited. There is insufficient evidence to provide guidelines to clinicians on the clinical management of periodontitis in overweight and obese individuals.     

A systematic review of persuasive marketing techniques to promote food to children on television

The ubiquitous marketing of energy‐dense, nutrient‐poor food and beverages is a key modifiable influence on childhood dietary patterns and obesity. Much of the research on television food advertising is focused on identifying and quantifying unhealthy food marketing with comparatively few studies examining persuasive marketing techniques to promote unhealthy food to children. This review identifies the most frequently documented persuasive marketing techniques to promote food to children via television. A systematic search of eight online databases using key search terms identified 267 unique articles. Thirty‐eight articles met the inclusion criteria. A narrative synthesis of the reviewed studies revealed the most commonly reported persuasive techniques used on television to promote food to children. These were the use of premium offers, promotional characters, nutrition and health‐related claims, the theme of taste, and the emotional appeal of fun. Identifying and documenting these commonly reported persuasive marketing techniques to promote food to children on television is critical for the monitoring and evaluation of advertising codes and industry pledges and the development of further regulation in this area. This has a strong potential to curbing the international obesity epidemic besieging children throughout the world.     

Systematic prevention of overweight and obesity in adults: a qualitative and quantitative literature analysis

To date, most interventions aimed at preventing obesity have underemphasized the application of systematic intervention development, implementation and evaluation. The present review provides a thorough insight in factors promoting implementation and/or effectiveness in interventions aimed at preventing overweight/obesity among adults. A total of 46 studies evaluating interventions aimed at preventing obesity were reviewed, followed by both qualitative and quantitative analyses. The Intervention Mapping protocol and the Environmental Research framework for weight Gain prevention (EnRG) were applied to analyse and classify the included studies. The interventions were categorized by setting (workplace, community, health care) and target group (ethnic minorities, pregnant women, [pre]menopausal women, smokers, people with intellectual disabilities). Generally, interventions were found to have potential in changing energy balance‐related behaviours and anthropometric outcomes. Effect sizes for changes in body mass index ranged between ?0.09 and 0.45. When the programme goal specifically aimed at weight management, the intervention was found to be more successful than interventions with programme goals that were aimed at preventing cardiovascular disease or improving general health status. Although a considerable part of studies included motivational interventions, only some actually assessed the effects on potential cognitive mediators. A general lack of reporting underlying theoretical models for behaviour change was observed as well as the inclusion of linkage groups and strategies to promote empowerment.     

Dairy consumption and overweight and obesity: a systematic review of prospective cohort studies

A comprehensive literature search was undertaken to examine the relationship between dairy consumption and overweight/obesity in prospective cohort studies. A literature search from 1980 through to April 2010 was conducted. Nineteen cohort studies met all the inclusion criteria and were included in the systematic review. Of the 19 cohort studies, 10 were among children and adolescents (aged 2 to 14 years, n = 53 to 12 829, follow‐up 8 months to 10 years) and nine among adults (aged 18 to 75 years, n = 248 to 42 696, follow‐up 2 years to 12 years). A range of dairy food exposure measures were used. Eight studies (three out of 10 studies involving children and five out of nine studies involving adults) showed a protective association against increasing weight gain (measured in various ways); one reported a significant protective association only among men who were initially overweight; seven reported no effect; one reported an increased risk (among children), and two reported both a decreased and increased risk, depending on the dairy food type. The evidence from prospective cohort studies for a protective effect of dairy consumption on risk of overweight and obesity is suggestive but not consistent, making firm conclusions difficult.     

Obesity, overweight and body-weight perception in a High Atlas Moroccan population

In order to study the prevalence of obesity and overweight and to understand how the human body is perceived among Moroccan mountain populations, we carried out a survey that covered a sample of 436 Amazigh individuals aged 20 years and more from the High Moroccan Atlas. Through this survey, we noticed that obesity is still low among men (2.4%), whereas the prevalence of obesity among women is alarming and reaches 13.3%. The prevalence of overweight is also high, especially among women, with 32.8% vs. 21.8% among men. Obesity prevalence, especially overweight, is higher than that recorded in the national rural level. The high prevalence of overweight that can develop to obesity should be taken into account mainly when dealing with women that still value overweight. In fact, women in our sample underestimate their overweight more than men and wish to have a heavier body.     

The prevention of overweight and obesity in children and adolescents: a review of interventions and programmes

Overweight and obesity are serious, large-scale, global, public health concerns requiring population-based childhood overweight and obesity prevention. The overall objective of this review is to identify aspects of successful childhood overweight prevention programmes. This objective will be met by assessing existing interventions quantitatively as well as qualitatively, identifying efficacy, effectiveness and implementation, and evaluating potential adverse effects of previous studies. This review was limited to school-based studies with a quantitative evaluation using anthropometric outcomes and that intervene on diet or activity-related behaviours. Quantitative and qualitative approaches are used to identify factors related to successful interventions as well as adverse consequences. Sixty-eight per cent of the interventions, or 17 of the 25, were 'effective' based on a statistically significant reduction in body mass index (BMI) or skin-folds for the intervention group. Four interventions were effective by BMI as well as skin-fold measures. Of these, two targeted reductions in television viewing. The remaining two studies targeted direct physical activity intervention through the physical education programme combined with nutrition education. Of the interventions reported here, one was effective in reducing childhood overweight but was also associated with an increase in underweight prevalence. Few other studies reported outcomes for underweight. The majority of overweight/obesity prevention programmes included in this review were effective. Physical education in schools and reducing television viewing are two examples of interventions that have been successful. Because few studies report on underweight prevalence, this review recommends giving more attention to preventing adverse outcomes by reporting the intervention impact on the frequency distribution for both BMI and adiposity measures.     

Prevalence of obesity and overweight in urban adult Nigerians

Obesity is increasingly a major health problem in parts of the developing world. It has reached epidemic proportions among Africans living in the Western Hemisphere; similar potential may exist in urban Africa. We explored this possibility in an urban setting in Nigeria, Africa's most populous nation. A screening survey was carried out among randomly selected 998 civil servants, 581 men and 417 women, in Ibadan, a major Nigerian city. Biographical data were collected using standardized questionnaires, and measurements of anthropometric indices, blood pressures and plasma glucose concentration. Obesity and overweight were defined by body mass index based on international criteria. Prevalence of obesity was 8.82% (confidence interval [CI] = 7.13%, 10.75%), overweight 17.45% (CI = 15.12%, 19.95%), and overweight plus obesity = 26.18% (CI = 23.47%, 29.03%). Prevalence of obesity among the women was 17.27% (CI = 13.76%, 21.24%) and for men 2.75% (CI = 1.58%, 4.43%). Among the women 42% were obese or overweight compared with 15% of the male population. Obesity and overweight were associated with higher socioeconomic status. Prevalence of obesity and overweight in the study population is comparable to rates seen in many industrialized countries, and rapidly emerging urbanized populations in Africa.