Nicotine dependence among adolescents in the European Union: How many and who are affected?

BACKGROUND: Nicotine dependence during adolescence increases the risk of continuing smoking into adulthood. The magnitude of nicotine dependence among adolescents in the European Union (EU) has not been established. We aimed to estimate the number of nicotine dependent 15-year-old adolescents in the EU, and identify high-risk groups. METHODS: The number of nicotine dependent 15-year-olds in the EU was derived combining: (i) total number of 15-year-olds in the EU (2013 Eurostat), (ii) smoking prevalence among 15-year-olds (2013/2014 HBSC survey) and (iii) proportion of nicotine dependent 15-year-olds in six EU countries (2013 SILNE survey). Logistic regression analyses identified high-risk groups in the SILNE dataset. RESULTS: We estimated 172 636 15-year-olds were moderately to highly nicotine dependent (3.2% of all 15 years old; 35.3% of daily smokers). In the total population, risk of nicotine dependence was higher in males, adolescents with poor academic achievement, and those with smoking parents or friends. Among daily smokers, only lower academic achievement and younger age of smoking onset were associated with nicotine dependence. CONCLUSION: According to our conservative estimates, more than 172 000 15-year-old EU adolescents were nicotine dependent in 2013. Prevention of smoking initiation, especially among adolescents with poor academic performance, is necessary to prevent a similar number of adolescents getting addicted to nicotine each consecutive year.

Determinants of weight loss maintenance: a systematic review.

BACKGROUND: Discerning the determinants of weight loss maintenance is important in the planning of future interventions and policies regarding overweight and obesity. We have therefore systematically synthesized recent literature on determinants of weight loss maintenance for individuals with overweight and obesity. METHODS: With the use of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, prospective studies were identified from searches in PubMed and PsycINFO from 2006 to 2016. We included articles investigating adults with overweight and obesity undergoing weight loss without surgery or medication. Included articles were scored on their methodological quality, and a best-evidence synthesis was applied to summarize the results. RESULTS: Our search resulted in 8,222 articles of which 67 articles were selected. In total, 124 determinants were identified of which 5 were demographic, 59 were behavioural, 51 were psychological/cognitive and 9 were social and physical environmental determinants. We found consistent evidence that demographic determinants were not predictive of weight loss maintenance. Behavioural and cognitive determinants that promote a reduction in energy intake, an increase in energy expenditure and monitoring of this balance are predictive determinants. CONCLUSION: This review identifies key determinants in weight loss maintenance. However, more research regarding cognitive and environmental determinants of weight loss maintenance is needed to advance our knowledge on determinants of weight loss maintenance.

A systematic review of school-based interventions targeting physical activity and sedentary behaviour among older adolescents.

Lack of physical activity (PA) and high levels of sedentary behaviour (SB) have been associated with health problems. This systematic review evaluates the effectiveness of school-based interventions to increase PA and decrease SB among 15-19-year-old adolescents, and examines whether intervention characteristics (intervention length, delivery mode and intervention provider) and intervention content (i.e. behaviour change techniques, BCTs) are related to intervention effectiveness. A systematic search of randomised or cluster randomised controlled trials with outcome measures of PA and/or SB rendered 10 results. Risk of bias was assessed using the Cochrane risk of bias tool. Intervention content was coded using Behaviour Change Technique Taxonomy v1. Seven out of 10 studies reported significant increases in PA. Effects were generally small and short-term (Cohen's d ranged from 0.132 to 0.659). Two out of four studies that measured SB reported significant reductions in SB. Interventions that increased PA included a higher number of BCTs, specific BCTs (e.g., goal setting, action planning and self-monitoring), and were delivered by research staff. Intervention length and mode of delivery were unrelated to effectiveness. More studies are needed that evaluate long-term intervention effectiveness and target SBs among older adolescents.

The differentiated effectiveness of a printed versus a Web-based tailored physical activity intervention among adults aged over 50.

This study provides insight in the effectiveness of a print-delivered and a Web-based physical activity (PA) intervention (with or without additional environmental information on local PA possibilities) among people aged over 50. Intervention groups (print-delivered basic [PB; n = 439], print-delivered environmental [PE; n = 435], Web-based basic [WB; n = 423], Web-based environmental [WE; n = 432]) and a control group (n = 411) were studied in a clustered randomized controlled trial. Participants received three times tailored advice within four months, targeting the psychosocial determinants of PA, and additional environmental information (in two conditions). Outcome measures include weekly minutes and days of sufficient PA 6 months after the start, considering age, gender, educational level, body mass index, the presence of a chronic physical limitation and PA intentions as possible effect moderators. The results showed that the PB (B = 192.47; 95% CI = 75.24-309.71; P = 0.003), the PE (B = 229.31; 95% CI = 108.73-349.89; P = 0.001) and the WB-intervention condition (B = 214.25; 95% CI 88.65-339.85; P = 0.002) resulted in significantly increased weekly minutes of PA. Only the printed conditions resulted in increased days of sufficient PA (PB: B = 0.63; 95% CI = 0.35-0.92; P < 0.001; PE: B = 0.55; 95% CI = 0.26-0.85; P = 0.001). Additional environmental information did not increase intervention effects. Differences in effect were found between age and gender subgroups. In conclusion, both printed and Web-based interventions can be effective in increasing PA in adults aged over 50.

Differences in the use and appreciation of a web-based or printed computer-tailored physical activity intervention for people aged over 50 years.

This study provides insight into the use and appreciation of a tailored physical activity intervention for people aged over 50 years in different intervention conditions (i.e. printed versus web-based and basic versus environmental). Participants (within a clustered randomized controlled trial) received printed or web-based-tailored advice three times within 4 months. Half of the participants also received environmental information. Differences in use and appreciation between both delivery modes and between the basic and environmental condition (similar delivery mode) were assessed at 3 (N = 935) and 6 (N = 649) months after baseline using analyses of variance and chi-square test. The use of the printed intervention (i.e. 92.7-98.2% read, 70.1-76.5% kept and 39.9-56.8% discussed) was significantly higher and printed intervention components were better appreciated than web-based intervention (scores, respectively, 6.06-6.91 versus 5.05-6.11 on a scale of 1-10). In-depth appreciation (e.g. reliability, perceived individualization) was average to high, without differences between intervention conditions. Additional environmental information did not increase appreciation; however, environmental intervention components were more used compared with basic intervention components. Integration of environmental components can stimulate active use of the intervention. To increase the public impact and prevent dropout by participants of web-based physical activity interventions, design modifications are needed for ease of use and improved appreciation.

Television in the bedroom and increased body weight: potential explanations for their relationship among European schoolchildren.

AIMS: A television in the bedroom is associated with measures of adiposity. We aimed to test if this association is mediated by any of (i) time spent watching television, (ii) sleep duration, (iii) physical activity level or (iv) consumption of soft drinks. METHOD: Data were from 7234 boys and girls aged 10-12 years in European countries involved in the EuropeaN Energy balance Research to prevent excessive weight Gain among Youth project (Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia and Spain). Waist circumference, height and weight were measured. The presence of a bedroom television, television viewing time, sleep duration, physical activity time and soft drink consumption were assessed by standardized questionnaires. RESULTS: Almost 40% of schoolchildren had a bedroom television, with the highest percentage among Hungarian children (65%) and lowest for Belgian, Slovenian and Spanish children (all ≈28%). A television in the bedroom was positively associated with time spent watching television, soft drink consumption and overweight and obesity (all P < 0.001). The relationship between a television in the bedroom and measures of body size was partly mediated by total television viewing time (proportion mediated for waist circumference 8.9%; for body mass index 8.3%) but not sleep duration, physical activity time or soft drink consumption. CONCLUSION: The strong association between a television in the bedroom and adiposity was at least partially mediated by television viewing time. The large proportion of European schoolchildren with a television in their bedroom is of concern. Parents should be aware of the potential consequences when placing a television in a child's bedroom and children should limit viewing time.

Differences in weight status and energy-balance related behaviours according to ethnic background among adolescents in seven countries in Europe: the ENERGY-project.

OBJECTIVE: The aim of this study was to explore differences in weight status and energy balance behaviours according to ethnic background among adolescents across Europe. METHODS: A school-based survey among 10-12-year-old adolescents was conducted in seven European countries. Weight, height and waist circumference were measured; engagement in physical activity, sedentary and dietary behaviour, and sleep duration was assessed by child and parent-report. A distinction between native and non-native ethnic background was based on language spoken at home, and the parents' country of birth. Analyses were conducted with and without adjustment for parental education. RESULTS: With valid data on both indicators of ethnic background for 5149 adolescents, 7307 adolescents (52% girls; 11.6 ± 0.7 years) participated. Significantly higher prevalence of overweight, obesity, body mass index and waist circumference were observed among non-native compared with native adolescents. Non-native adolescents had less favourable behavioural patterns (sugary drinks, breakfast skipping, sport, TV and computer time, hours of sleep) with the exception of active transport to school. Similar patterns were observed for both indicators of ethnicity, and in most of the separate countries; however, in Greece, weight status indicators were better among non-native adolescents. After adjustment for parental education, most differences remained significant according to country of origin of the parents, but not according to language spoken at home. CONCLUSION: Adolescents of native ethnicity of the country of residence have, in general, more favourable weight status indicators and energy balance-related behaviours than adolescents of non-native ethnicity across Europe.

Weight status of European preschool children and associations with family demographics and energy balance-related behaviours: a pooled analysis of six European studies.

This study aimed to (i) gain insight in the prevalence of overweight indices in European preschoolers (4-7 years); (ii) identify energy balance-related behaviours associated with overweight/obesity; and (iii) identify children at risk for overweight/obesity. Secondary analyses of six European data sets were conducted according to standardized protocols. Based on objectively measured height and weight, prevalence of overweight and obesity across the countries ranged from 8% to 30% and 1% to 13%, respectively, with highest rates in Southern European countries (i.e. Spain and Greece). Positive associations between sedentary behaviours and overweight indices were found. Physical activity and dietary behaviours were not associated, possibly because of methodological limitations. Children of parents with high body mass index or low socioeconomic status were at increased risk of overweight/obesity. In conclusion, large differences in prevalence of overweight and obesity among preschoolers across Europe were observed. Future obesity prevention interventions in preschoolers should target screen time giving specific attention to children from overweight and/or low socioeconomic status parents. There is a need for high methodological quality studies, preferably with a long-term prospective design using sensitive, valid and reliable measures of behaviours, assessing whether and which physical activity and dietary behaviours are associated with overweight in preschoolers.

Energy balance-related behaviours associated with overweight and obesity in preschool children: a systematic review of prospective studies.

The current review aimed to systematically identify dietary, physical activity and sedentary behaviours in preschool children (4-6 years of age) that are prospectively related to overweight or obesity later in childhood. Prospective studies published between January 1990 and June 2010 were selected from searches in PubMed, EMBASE, PsycINFO, CINAHL and Cochrane Library. Studies examining the prospective association between at least one relevant behaviour measured during preschool period (children aged 4-6 years at baseline) in relation to at least one anthropometric measurement at follow-up (age <18 years) were included. Harvest plots were used to summarize the results and draw conclusions from the evidence. Of the 8,718 retrieved papers, 23 papers reporting on 15 different study samples were included in this review. Strong evidence was found for an inverse association between total physical activity and overweight. Moderate evidence was observed for a positive association between television viewing and overweight. Because of the heterogeneity in the assessed dietary behaviours, insufficient evidence was found for an association between dietary intake or specific dietary behaviours and overweight. These results suggest that interventions aiming to prevent overweight among preschool children should focus on promotion of total physical activity and limitation of screen time and that further research is needed to establish whether and which dietary behaviours are important for obesity prevention in this age group. However, despite the lack of evidence for dietary behaviours from the present review, future interventions may already target specific dietary behaviours that are highly prevalent and for which there a clear rationale as well as preliminary evidence that these behaviours are associated with overweight.

What works in school-based energy balance behaviour interventions and what does not? A systematic review of mediating mechanisms.

OBJECTIVE: Obesity prevention requires effective interventions targeting the so-called energy balance-related behaviours (that is, physical activity, sedentary and dietary behaviours). To improve (cost-)effectiveness of these interventions, one needs to know the working mechanisms underlying behavioural change. Mediation analyses evaluates whether an intervention works via hypothesised working mechanisms. Identifying mediators can prompt intervention developers to strengthen effective intervention components and remove/adapt ineffective components. This systematic review aims to identify psychosocial and environmental mediators of energy balance-related behaviours interventions for youth. METHOD: Studies were identified by a systematic search of electronic databases (PubMed, Embase, PsycINFO, ERIC and SPORTDiscus). Studies were included if they (1) were school-based randomised controlled or quasi-experimental studies; (2) targeted energy balance behaviours; (3) conducted among children and adolescents (4-18 years of age); (4) written in English; and (5) conducted mediation analyses. RESULTS: A total of 24 studies were included. We found strong evidence for self-efficacy and moderate evidence for intention as mediators of physical activity interventions. Indications were found for attitude, knowledge and habit strength to be mediators of dietary behaviour interventions. The few sedentary behaviour interventions reporting on mediating effects prevented us from forming strong conclusions regarding mediators of sedentary behaviour interventions. The majority of interventions failed to significantly change hypothesised mediators because of ineffective intervention strategies, low power and/or use of insensitive measures. CONCLUSION: Despite its importance, few studies published results of mediation analysis, and more high-quality research into relevant mediators is necessary. On the basis of the limited number of published studies, self-efficacy and intention appear to be relevant mediators for physical activity interventions. Future intervention developers are advised to provide information on the theoretical base of their intervention including the strategies applied to provide insight into which strategies are effective in changing relevant mediators. In addition, future research is advised to focus on the development, validity, reliability and sensitivity of mediator measures.

Determinants of awareness, initiation and maintenance of physical activity among the over-fifties: a Delphi study.

To develop effective interventions to stimulate physical activity (PA), insight into its underlying variables is needed. The aim of this study was to obtain an overview of the most relevant determinants of awareness, initiation and maintenance of PA among the over-fifties by means of a three-round Delphi study. In the first round, 17 key-experts outlined possible relevant determinants into an open-ended electronic questionnaire. In the second round, 118 experts completed a structured electronic questionnaire that was based on the first round results, in which they scored each determinant on its relevance. In the third round, experts were asked to re-rate the relevance of each determinant, after feedback was given about the group median relevance score. After three rounds, the experts agreed on 30 relevant determinants of the three phases of PA. When compared with longitudinal studies, the Delphi study pointed out new concepts, such as several post-motivational and social and environmental determinants as possible relevant determinants, suggesting that this method has the potential to trace new and promising determinants. The results further showed that next to similarities, much dissimilarity in relevant determinants of awareness, initiation and maintenance of PA was found, suggesting that most determinants could be phase specific.