Role of dietary intake and physical activity in reducing weight social inequalities among adolescents: an application of G-formula to PRALIMAP-INÈS trial.

Interventions aiming to reduce social inequalities of weight status in adolescents usually focus on lifestyle behaviours, but their effectiveness is limited. This study analysed the effect of achieving levels of dietary intake (DI) and/or physical activity (PA) guidelines on reducing social inequalities in weight status among adolescents. We included adolescents from the PRomotion de l'ALIMentation et de l'Activité Physique - INÉgalité de Santé (PRALIMAP-INÈS) trial with weight status data available at baseline and 1-year follow-up (n=1130). PA and DI were measured using the International Physical Activity Questionnaire and a validated food frequency questionnaire, respectively. We estimated the likelihood of a 1-year reduction in body mass index z-score (BMIz) and population risk difference (PRD) under hypothetical DI and PA levels and socioeconomic status using the parametric G-formula. When advantaged and less advantaged adolescents maintained their baseline DI and PA, we found social inequalities in weight status, with a PRD of a 1-year reduction in BMIz of -1.6% (-3.0%; -0.5%). These inequalities were not observed when less advantaged adolescents increased their proportion of achieving DI guidelines by 30% (PRD=2.2% [-0.5%; 5.0%]) unlike the same increase in PA (PRD= -3.9% [-6.8%; -1.3%]). Finally, social inequalities of weight status were not observed when levels of achievement of both PA and DI guidelines increased by 30% (PRD= 2.2% [-0.5%; 4.0%]). Enhancing DI rather than PA could be effective in reducing social inequalities in weight status among adolescents. Future interventions aiming to reduce these inequalities should mostly target DI to be effective.

Behavioural risk patterns in adolescents with excess weight participating in the PRALIMAP-INÈS trial.

OBJECTIVE: To investigate clustering of risk behaviours in adolescents with excess weight. DESIGN: Cross-sectional analysis of baseline data from the PRALIMAP-INÈS trial. Information on food frequency consumption (fruit, vegetables, sugary products and beverages), physical activity, sedentary behaviour (week and weekend days), smoking and alcohol consumption (current frequency and intoxication episodes) and socio-demographic data was collected using self-reported questionnaires. Behavioural risk factors were entered as categorical variables in a two-step clustering procedure: multiple correspondence analysis followed by hierarchical clustering. Associations between cluster membership and socio-demographic variables were investigated using multivariable multinomial logistic regression. SETTING: French PRALIMAP-INÈS trial. PARTICIPANTS: Adolescents with excess weight. RESULTS: A total of 1391 participants (13-18 years old, 58·2 % female) were included in the analysis, which resulted in the identification of four groups of participants, including, respectively, 543 (39·0 %), 373 (26·8 %), 246 (17·7 %) and 229 (16·5 %) participants. Clusters 1 and 4 showed associations of rather healthy behaviours (high physical activity and low consumption of sugary products; high consumption of fruit and vegetables, respectively), while clusters 2 and 3 showed associations of rather unhealthy behaviours (high sedentary behaviour and low consumption of fruit and vegetables; smoking and alcohol consumption, respectively). Both social status and family structure were associated with cluster membership. CONCLUSIONS: Risk behaviour patterns in adolescents with excess weight were clustered in both healthier and less healthy ways, with a complex interplay with socio-demographic factors.

Longitudinal patterns of lifestyle behaviours in adolescence: a latent transition analysis.

The interdependence among eating behaviour (EB), physical activity (PA) and sedentary time (ST) suggests simultaneously identifying homogeneous profiles and describing their changes. This study aimed to (1) identify cross-sectional lifestyle behaviour profiles and their 2-year changes among French school-age adolescents and (2) identify factors associated with these profiles and changes. Longitudinal data from adolescents who participated in the PRomotion de l'ALIMentation et de l'Activité Physique trial were used. PA and ST were assessed with the International Physical Activity Questionnaire and EB with a FFQ. Profiles at baseline and their changes were identified by latent transition analysis. Multinomial logistic regression models were used to identify factors associated with profiles and their changes. Among 2390 adolescents included (14-18 years), five baseline profiles that differed mainly in EB were identified: 'healthy diet and high PA (7·9 %)', 'big eater and moderate to high PA (23·8 %)', 'healthy diet and low PA (31·2 %)', 'restrictive diet and moderate PA (20·6 %)' and 'sugar products, nibbling and moderate PA (16·5 %)'. Young adolescents, those who were overweight or obese and socially advantaged, were more in the 'healthy diet and low PA' than others. Boys, older and socially less advantaged adolescents exhibited more 'unfavourable' than 'mixed' changes, while adolescents with overweight or obesity had less 'unfavourable' than 'mixed' changes. In conclusion, adolescents were twice the number in the least than the most favourable profile. Findings highlighted the importance of EB among adolescents and suggest taking adolescents' sociodemographic and weight characteristics into account in interventions aimed at acting on adolescents' behaviours.

Effectiveness of a socially adapted intervention in reducing social inequalities in adolescence weight. The PRALIMAP-INÈS school-based mixed trial.

BACKGROUND: A high prevalence of overweight/obesity among low socioeconomic status adolescents contributes to health inequalities. However, evidence-based interventions for reducing social inequalities in adolescent weight are lacking. We aimed to investigate whether strengthened care management for adolescents with low socioeconomic status has an equivalent effect in reducing overweight as standard care management in adolescents with high status. METHODS: PRALIMAP-INÈS was a multicentre trial including 35 state-run high and middle schools in the north-eastern France. A population-based sample of 1639 adolescents aged 13-18 years with screened and clinically confirmed overweight/obesity were proposed for inclusion and divided into two groups by the Family Affluence Scale score: advantaged (score > 5), receiving standard care management (A.S) and less-advantaged randomly assigned to two groups (1:2 ratio): standard care management (LA.S) and standard and strengthened care management (LA.S.S). Interventions were based on the proportionate universalism principle: universal standard care for all groups and proportionate care for the LA.S.S group. Main outcome was body mass index z-score (BMIz) assessed before and 1 year after inclusion. RESULTS: A total of 1419 adolescents were included and 1143 followed up at 1 year: 649 in A.S, 158 in LA.S and 336 in LA.S.S groups. BMIz decreased significantly for boys (-0.11 [95% CI, -0.13 to -0.08]; p < 0.0001) and girls (-0.05 [-0.08 to -0.03]; p < 0.0001). No equivalence between LA.S.S and A.S groups was evidenced. For girls, the trend to superiority for LA.S.S was confirmed by the more favourable change (-0.06 [-0.11 to -0.01]; p = 0.01) observed on superiority analysis, with no differential change for boys (0.02 [-0.03 to 0.08]; p = 0.41). CONCLUSIONS: A public health school-based intervention using the proportionate universalism principle may be effective in not worsening or even reducing overweight social inequalities in adolescents, especially for girls. Overcoming social barriers may help health professionals dealing with the burden and inequalities of overweight in adolescents.

Physical activity rather than sedentary behaviour is socially determined in French adolescents with overweight and obesity.

Social differences in prevalence of overweight and obesity among adolescents, known as the weight social gradient, could be explained by differences in behaviours between social classes. This study examined the respective association of physical activity (PA), sedentary behaviour (SB) and weight status with adolescents' socioeconomic status. We used cross-sectional data for 1935 adolescents (13-18 years old) with overweight or obesity who participated in the PRALIMAP-INÉS (PRomotion de l'ALImentation et de l'Activité Physique - INÉgalités de Santé) trial conducted in northeastern France between 2012 and 2015. Adolescents completed the International Physical Activity Questionnaire for PA and SB and the Family Affluence Scale for socioeconomic status. Weight status was assessed by the body mass index (BMI) and BMI z-score. Social gradient of weight status, PA and SB were described according to the Family Affluence Scale (slopes) and evidenced by the linear trend test (p). Adolescents' socioeconomic status was positively associated with PA practice (frequency, vigorous PA and leisure-time PA), but there was no association with their SB. The results confirmed a significant weight social gradient: BMI (ß = 0.37, p < .0001) and BMI z-score (ß = 0.07, p = .0001). The weight social gradient in adolescents was mostly associated with PA (5.7% to 8.1%) rather than SB (2.7% to 5.7%). Nearly 14% of BMI z-scores could be related to a combined PA and SB effect. PA was found an important factor of weight social gradient in adolescence. Actions aimed at preventing weight social inequalities among adolescents could include PA promotion as lever. CLINICAL TRIALS REGISTRY AND NUMBER: ClinicalTrials.gov (NCT01688453).

Measuring adolescents' weight socioeconomic gradient using parental socioeconomic position.

Background: There is an evidence of social inequalities in weight status in adolescence but the diversity of family socioeconomic status (SES) indicators can lead to discrepant findings. We aimed to identify how combination of family SES indicators can help measuring weight socioeconomic gradient (WSG) among adolescents. Methods: Cross-sectional data from 2113 adolescents (13-18 years old) of the PRALIMAP-INÈS trial were used. Multiple SES indicators and assessment of weight status including body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and self-perception of overweight were used. We used principal component analysis (PCA) followed by structural equation models to identify SES dimensions. A dimension normalized score was calculated ranging from 1 to 10 (a high score corresponding to high SES). Linear regression models (linear trend test) were used to assess the WSG. Results: Three SES dimensions were identified: (i) 'Family social status', (ii) 'Family education level' and (iii) 'Family income level'. BMI was significantly lower in highly advantaged compared with highly less advantaged [-1.64 (-2.39; -0.89) for family social dimension, -0.86 (-1.37; -0.36) for family education level and -2.35 (-3.65; -1.05) for family income level]. Similar results were observed for all weight indicators excepted for self-perception of overweight status. Socially less advantaged adolescents perceived themselves less fat than they were. Conclusion: Although WSG was evident in adolescence, association between SES and weight status differed according to objective or perceived weight indicators. The proposed SES dimension can be applied in other field and future studies are needed to confirm our findings.

Association of socioeconomic, school-related and family factors and physical activity and sedentary behaviour among adolescents: multilevel analysis of the PRALIMAP trial inclusion data.

BACKGROUND: Social differences among adolescents in physical activity and sedentary behaviour have been identified but are not well explained. The current study aimed to identify socioeconomic, family and school-related associated factors with physical activity and sedentary behaviour among high-school adolescents. METHODS: This was a cross-sectional analysis of T0 physical activity and sedentary behaviour of 2523 students 14 - 18 years old recruited for the PRALIMAP trial from 24 French state-run high schools. Data were collected by self-administered questionnaire at the start of grade 10. Adolescents completed the International Physical Activity Questionnaire for physical activity and sedentary behaviour and an ad hoc questionnaire for active commuting and sport participation. Statistical analyses involved linear and logistic regressions. RESULTS: Socioeconomic, family or school variables were associated with levels of physical activity and sedentary behaviour for both boys and girls, but no factor, except perceived parental physical activity level, was associated with total energy expenditure (total physical activity) for either gender. Adolescents with privileged and less privileged socioeconomic status reported the same total amount of energy expenditure. CONCLUSIONS: Total physical activity score alone is not sufficient to assess the physical activity of adolescents. These findings may have implications for better understanding of social inequalities in this context and recommendations to prevent overweight. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov ( NCT00814554 ). The date of registration: 23 December 2008. Registration was not required at the time of the start of PRALIMAP for public health and prevention programmes and trials.

Cumulative and bidirectional association of physical activity and sedentary behaviour with health-related quality of life in adolescents.

BACKGROUND: The directionality of the association of physical activity (PA) and sedentary behaviour (SB) with health-related quality of life (HRQoL) remains unknown in adolescents. This study aimed to investigate the association of 2-year cumulative level of PA and SB with HRQoL and the reverse association. METHODS: We included 1445 adolescents in France from a 2-year longitudinal study with three follow-up times (PRALIMAP trial). At each follow-up, adolescents completed the International Physical Activity Questionnaire for PA and SB and the Duke Health Profile for HRQoL. Statistical analyses involved linear and logistic regressions adjusted for socio-demographic characteristics. RESULTS: The cumulative number of times an adolescent achieved the PA recommendations during the 2 years was associated with better physical, mental, social and general HRQoL (p for trend < 0.0001). In contrast, high SB predicted low HRQoL for most dimensions except social HRQoL (p = 0.12). Combining PA and SB, the effect of recommended PA on HRQoL was offset in part by high SB. In the reverse association, high HRQoL predicted high PA (overall, vigorous, moderate and recommended PA), but was not associated with SB. CONCLUSIONS: The association between PA and HRQoL was cumulative and bidirectional among adolescents, whereas low HRQoL seemed to be a consequence of high SB rather than a cause (cumulative but not bidirectional). Promoting recommended PA and low SB may help improve HRQoL among adolescents, with a possible virtuous cycle with regard to PA.

[Participation of overweight and socially disadvantaged adolescents in an intervention to promote physical activity in school]. / Participation d'adolescents en surpoids de milieu défavorisé à une intervention de promotion de l'activité physique à l'école.

Initial participation in PRALIMAP-INÉS group activities was high among disadvantaged teenagers with financial difficulties, but it was more difficult to maintain their participation throughout the programme. Identification of factors that can maintain participation is a major challenge for continuity of the programme..

Physical Activity and Eating Behavior Inequalities Mediating the Effects of Socioeconomic Status and Sex on Adolescent Quality of Life: Insights of the PRALIMAP Trial.

BACKGROUND: This study aimed to quantify the 2-year mediating effects of physical activity (PA) and eating behavior (EB) on socioeconomic and sex inequalities in quality of life (QoL) among French adolescents. METHODS: Adolescents from a 2-year school-based trial were included. PA and EB were assessed at baseline, 1 year, and 2 years using the International Physical Activity Questionnaire and an eating habits questionnaire, respectively. QoL was measured at 2 years using the Duke Health Profile questionnaire. The mediating effect of adherence to PA and EB guidelines in the associations between socioeconomic status or sex and QoL was analyzed with a counterfactual method. RESULTS: Among the 3562 included adolescents (mean age, 15.2 [0.6] y), being a boy and having a high socioeconomic status was associated with high QoL. Differences in QoL by socioeconomic status were mediated by adherence to guidelines for PA (up to 10.2%) and EB (up to 8.8%), and differences in QoL by sex were predominantly mediated by adherence to guidelines for PA (up to 163.8%). CONCLUSIONS: Policies, programs, and interventions designed to reduce socioeconomic and sex inequalities in QoL among adolescents could use PA and EB as leverage.

Universal School-Based Intervention Does Not Reduce Socioeconomic Inequalities in Weight Status among Adolescents.

Background: Differences in weight status by socioeconomic position occur during adolescence and is known as weight social gradient (WSG). The PRALIMAP (Promotion de l'ALIMentation et de l'Activité Physique) trial highlighted that a universal intervention was effective in reducing overweight and obesity prevalence among adolescents. However, its ability to reduce the WSG is unclear. This study aimed to evaluate the impact of the PRALIMAP intervention on the WSG among adolescents. Methods: Data were obtained from 3504 adolescents who participated in the school-based PRALIMAP trial between 2006 and 2009. The PRALIMAP study consisted of three interventional strategies: educational, environmental, screening and care. Weight status was assessed by body mass index (BMI) z-score and overweight and obesity prevalence. The "indice de position sociale des élèves" was used to measure adolescents' socioeconomic status. Linear regression and hierarchical models were used to assess the WSG and its evolution, respectively. Results: Among all adolescents (14-18 years old), significant WSG was identified at baseline: BMI z-score (ß = -0.06; p < 0.0001), overweight and obesity prevalence (ß = -2.86; p < 0.0001). Overall, the intervention conferred no significant reduction in the WSG: BMI z-score (ß = -0.01 [-0.02 to 0.01], p = 0.48), overweight and obesity prevalence (ß = -0.01 [-0.07 to 0.05], p = 0.73). Similar results were observed for adolescents whatever the interventional strategy they benefited from in the PRALIMAP trial. Conclusions: This study provided no evidence that the PRALIMAP universal intervention was effective in reducing the socioeconomic inequalities in weight status among adolescents. Different interventions that account for social differences should be considered to tackle these inequalities.

Reach and Acceptability of a Mobile Reminder Strategy and Facebook Group Intervention for Weight Management in Less Advantaged Adolescents: Insights From the PRALIMAP-INÈS Trial.

BACKGROUND: Although information and communication technology interventions appear to be a promising means of reducing the health inequality gap in overweight and obesity prevention, research on information and communication technology interventions is lacking outside the Anglo-Saxon world. OBJECTIVE: The aim of this study was to assess the reach and acceptability of 2 information and communication technology interventions delivered as part of a French nutritional program: an SMS text messaging (short message service, SMS) attendance-reminder for collective sessions strategy and a Facebook challenge group. METHODS: This study sample comprised 262 socially less advantaged overweight adolescents aged between 13 and 18 years. The information and communication technology interventions were carried out during the 2013-2014 academic year in 33 French state-run schools. For the SMS attendance-reminder for collective sessions strategy, at the start of the academic year, adolescents were asked to give their mobile number. SMS attendance-reminders were sent shortly before each of the 5 collective sessions. For the Facebook challenge group, adolescents were invited to join a closed Facebook group in which challenges on physical activity and on diet were posted weekly. Process data and 2 sets of face-to-face interviews were also used to interpret participation rates and access to Facebook. Appreciation for both interventions was evaluated by a questionnaire at the end of the academic year. RESULTS: Of the recruited adolescents, 79.0% (207/262) gave their mobile number, reflecting high access to a mobile phone. Giving a number was significantly more likely for girls (odds ratio [OR] 2.1, 95% CI 1.1-3.9; P=.02) and adolescents in a vocational or general high school as opposed to middle school (OR 1.0, 95% CI 0.4-2.7; OR 0.2, 95% CI 0.1-0.5; P<.001). Indicating a mobile number at the start of the year was not significantly associated with participation in collective sessions. Of the adolescents seen at the start-of-year face-to-face interviews, 78.1% (153/196) declared an interest in the Facebook challenge group, which implies having a Facebook account or being able to have access to one. However, only 21 adolescents went through the process of joining the group. Although there was satisfaction with the Facebook group among the participants, the low participation rate in the Facebook group does not allow conclusions to be drawn with confidence. CONCLUSIONS: The results are in line with the claim that using information and communication technologies in health programs is unlikely to widen health inequalities. However, in this population of French adolescents, mobile phone strategies seem more adapted to a high school context, and caution should be exercised with a younger audience. Although there is positive appreciation of the SMS attendance-reminders and a Facebook intervention is initially highly appealing to less advantaged adolescents, no evidence of impact could be demonstrated. These results highlight the difficulty in assessing the impact of specific interventions in complex health programs. TRIAL REGISTRATION: Clinicaltrials.gov NCT01688453; https://clinicaltrials.gov/ct2/show/NCT01688453 (Archived by WebCite at http://www.webcitation.org/6yy6EQ0SM).

Using facilitator-receiver peer dyads matched according to socioeconomic status to promote behaviour change in overweight adolescents: a feasibility study.

OBJECTIVE: To evaluate the feasibility of an innovative peer intervention promoting healthy eating and physical activity, which purposefully selected peer facilitators according to socioeconomic status to target less-advantaged overweight receivers. SETTING: Nine high schools, two middle schools. PARTICIPANTS: One hundred and fifty-six adolescents were approached to become facilitators, of whom 18 were trained. Thirty-two of 56 potential receivers agreed to participate. INTERVENTION: The peer intervention was carried out in 2013-2014 and embedded in a larger trial: PRALIMAP-INÈS (Promotion de l'ALIMentation et l'Activité Physique-INEgalité de Santé). Facilitanoators were selected and trained to organise weight-control activities with specific peer receivers participating in the programme. PRIMARY AND SECONDARY OUTCOME MEASURES: Different types of data were collected to assess demand, acceptability, implementation and practicality of the intervention. For the facilitators, this included 6 training sessions, 11 mid-programme interviews, 4 end-of-programme sessions, telephone notes and text message exchanges. All six potential receivers in one school were also interviewed. Sociodemographic and health characteristics were also analysed. RESULTS: Agreeing to participate was more likely when asked by a peer compared with a professional (51.2% discordant pairs; p<0.02). Twelve activities, mostly based on physical activity and implemented during weekends or holidays, were carried out. The mean age of active receivers was 16 and their body mass index was higher than other participants. For both facilitators and active receivers, there were more participating girls. Qualitative analysis reveals key implementation challenges for facilitators. Interviews with the receivers highlight social difficulties, with most feeling bad about their appearance and wanting to lose weight. Those who participated in peer activities were very positive about the experience especially social support. CONCLUSIONS: The present study suggests the peer intervention is feasible provided organisational difficulties are addressed. Good practice recommendations are formulated, including a longer training session, organising a joint meeting with the facilitators and receivers, matching dyads on place of residence and multiplying modes of contact. TRIAL REGISTRATION NUMBER: NCT01688453.

Reducing social inequalities in access to overweight and obesity care management for adolescents: The PRALIMAP-INÈS trial protocol and inclusion data analysis.

BACKGROUND: Despite social inequalities in overweight/obesity prevalence, evidence-based public health interventions to reduce them are scarce. The PRALIMAP-INÈS trial aimed to investigate whether a strengthened-care management for adolescents with low socioeconomic status has an equivalent effect in preventing and reducing overweight as a standard-care management for high socioeconomic status adolescents. METHODS: PRALIMAP-INÈS was a mixed, prospective and multicenter trial including 35 state-run schools. It admitted overweight or obese adolescents, age 13-18 years old, for 3 consecutive academic years. One-year interventions were implemented. Data were collected before (T0), after (T1) and post (T2) intervention. Among 2113 eligible adolescents who completed questionnaires, 1639 were proposed for inclusion and 1419 were included (220 parental refusals). Two groups were constituted according to the Family Affluence Scale (FAS) score: the less advantaged (FAS≤5) were randomly assigned to 2 groups in a 2/1 ratio. The 3 intervention groups were: advantaged with standard-care management (A.S, n = 808), less advantaged with standard-care management (LA.S, n = 196), and less advantaged with standard and strengthened-care management (LA.S.S, n = 415). The standard-care management was based on the patient education principle and consisted of 5 collective sessions. The strengthened-care management was based on the proportionate universalism principle and consisted of activities adapted to needs. INCLUSION RESULTS: The written parental refusal was less frequent among less advantaged and more overweight adolescents. A dramatic linear social gradient in overweight was evidenced. DISCUSSION: The PRALIMAP-INÈS outcomes should inform how effectively a socially adapted public health program can avoid worsening social inequalities in overweight adolescents attending school. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01688453).

Adolescents' Physical Activity and Sedentary Behavior: A Pathway in Reducing Overweight and Obesity. The PRALIMAP 2-Year Cluster Randomized Controlled Trial.

BACKGROUND: explaining why and how overweight prevention programs were effective was a real need; especially the potential role of physical activity (PA) and sedentary behavior (SB) should be highlighted. This study aimed to evaluate the 2-year effectiveness of a screening and care strategy in adolescents' weight reduction with regards to PA and SB change. METHODS: 1745 adolescents aged 15.1 years from PRALIMAP trial was included (n = 840 for screening and care group and n = 905 for control group). PA and SB time (international physical activity questionnaire: IPAQ), body mass index (BMI), and BMI z-score were assessed at inclusion and after 2-year intervention. Hierarchical mixed models were applied. RESULTS: Compared with the control group, screening and care strategy was associated with an increase in global PA (58 min/week), a moderate PA (43 min/week), the adherence to the French PA guidelines (OR = 1.3), and a decrease in SB (-198 min/week). The 2-year weight change decreased when adjusted for PA and SB suggesting that the effect of screening and care strategy was partly mediated by PA and SB. CONCLUSION: Screening and care intervention seemed to be effective in increasing PA and decreasing SB. The induced PA and SB modifications contributed to the observed weight change.