Peer weight norm misperception as a risk factor for being over and underweight among UK secondary school students

Digital social multitasking (DSMT) and digital stress among adolescents: A peer norm perspective

Background

Digital stress refers to the stress resulting from persistent use of digital media. Given its major implications for well-being, it is crucial to explore how the use of digital media would contribute to the stress. Drawing on the frameworks of DSMT (i.e., using a digital device during social interactions) and perceived peer norms, we explored whether and how perceived peer norms of DSMT and adolescents' own DSMT were associated with digital stress.

Method

Adolescents between the ages of 12 and 18 were recruited through the Qualtrics survey panels. A total of 2105 adolescents completed a one-time online survey (Mage = 15.39, S.D. = 1.82).

Results

Path analysis revealed that all three self-DSMT variables (level, positive self-perception, negative self-perception) were associated with higher digital stress, with level and negative self-perception having stronger associations than did positive self-perception. Furthermore, peer DSMT level was related to higher digital stress both directly and indirectly through all three self-DSMT variables. Positive peer perception of DSMT was indirectly related to higher digital stress through higher self-DSMT level and more positive self-perception of DSMT, but was related to lower digital stress through reduced negative self-perception of DSMT. Negative peer perception of DSMT contributed to higher digital stress both directly and indirectly by intensifying teens' own negative perception of DSMT. Judging from the total-paths coefficients, all three peer norm variables were related to higher digital stress, with level having the largest coefficient, followed by negative peer perception and finally positive peer perception of DSMT.

Discussion and conclusion

All three perceived peer norms of DSMT (level, positive perception, negative perception) had the potential to increase digital stress directly and/or via impacting teens' own engagement in and perceptions of DSMT, with perceived peer engagement and negative peer perception being the greater risk factors. At the individual level, a similar pattern emerged-self-DSMT level and negative self-perception had noticeably stronger associations with digital stress than did positive self-perception.

Swap Up Your Meal: A Mass Media Nutrition Education Campaign for Oklahoma Teens

To address a statewide need for obesity prevention, the Oklahoma Tobacco Settlement Endowment Trust launched Swap Up in 2021, a mass media nutrition education effort for teens, ages 13-18. Swap Up utilizes the SAVI messaging approach, an audience-centric message development framework that recognizes barriers to healthy living and offers realistic solutions. Five months into the campaign, an online survey was conducted (n = 200) to assess short-term program goals related to campaign delivery, engagement, and relevance. A secondary, long-term goal related to documenting and understanding self-reported changes in past month nutrition-related behaviors was also explored. A majority of participants (72%) reported aided awareness of the campaign brand logo/advertisements, and awareness (83%) of at least one main message. Nearly half (44%) of the participants reported at least one engagement with digital media. Main message recognition, perceived relevance, and self-reported nutritional behaviors were consistently highest among those reporting both campaign awareness and digital engagement. Ultimately, Swap Up reached and delivered nutrition education messages to Oklahoma teens within the first year of launch, as intended, and was associated with self-reported changes in recent behavior. This study provides evidence that SAVI offers a promising approach for nutrition education, and underscores why digital and social media engagement strategies are critical for mass media teen behavior change campaigns. Campaign implementation and evaluation are ongoing.

Associations between Perceived Social Eating Norms and Initiation and Maintenance of Changes in Dietary Habits during the First COVID-19 Lockdown in France

Changes in dietary habits of the French population have been reported during the national lockdown that was enforced due to the COVID-19 pandemic. This study investigated whether perceived social eating norms were associated with the initiation and maintenance of dietary changes that took place as a result of lockdown. An online study collected information on (1) changes in consumption implemented during the lockdown and the maintenance of these changes, and (2) perceptions about changes in consumption implemented during lockdown by household members, relatives out of home, and the general population. The changes in consumption were classified as foods to increase or to decrease according to French national recommendations. The perception of changes to dietary habits by household members and relatives out of home was related to the changes made by individuals for each of the food categories (all p < 0.05) but not to the perception of changes made the general population. Increased consumption of foods to increase was more likely to be maintained when there was a positive perception of the changes made by household members (p = 0.03). These results highlight the influence of the perception of social eating norms, especially by household members and relatives, on the implementation of dietary changes during lockdown and suggest that social eating norms can have a lasting influence.

Do emerging adults know what their friends are doing and does it really matter? Methodologic challenges and associations of perceived and actual friend behaviors with emerging adults' disordered eating and muscle building behaviors

Disordered eating and muscle building behaviors are common among emerging adults, and friends may be a particularly salient social influence. Epidemiologic research often includes questions about participants' perceptions of their friends. A less common approach, with greater logistical challenges, is to ask for friend nominations and then survey friends about their actual behaviors. The comparability of these different approaches is unknown. This study addresses the following research questions: 1) What is the feasibility of collecting data from emerging adults' friends in epidemiologic research? 2) Do perceptions of friends' weight- and shape-related behaviors align with friends' actual behaviors? and 3) Are perceptions or friends' actual behaviors more strongly and consistently associated with emerging adults' behaviors? Participants (N = 2383) in the EAT (Eating and Activity over Time)-2018 study in Minnesota, USA, were asked to nominate up to three friends and provide data about those friends' weight- and shape-related behaviors (i.e. perceptions); nominated friends were invited to complete an abbreviated survey and report on their own same behaviors (i.e. actual). Among the invited friends, 191 responded and were linked to the 152 EAT 2018 participants who nominated them. Descriptive statistics, Spearman's correlations, and logistic regression were used to address the research questions. The response rate for nominated friends was very low (9.9%), suggesting this approach may have low feasibility for epidemiologic studies of emerging adults. Emerging adults' perceptions of their nominated friends' weight and shape-related behaviors generally did not align well with the behaviors reported by those friends. Furthermore, analytic models found different associations between friends' behavior and EAT 2018 participant behaviors, depending on the measure of friends' behavior used (perceived or actual). Careful consideration of the pros and cons of each study design is essential to build an evidence base and support interventions regarding emerging adults' weight- and shape-related health.

Body satisfaction and body weight in under- and healthy-weight adolescents: mediating effects of restrictive dieting, healthy and unhealthy food intake

PURPOSE

Theoretical models, such as the transdiagnostic model of eating disorders highlight the role of cognitive factors (e.g., the way people perceive their bodies) and their associations with maladaptive weight management behaviors resulting in underweight. This paper aims at testing the indirect association of adolescent's body satisfaction and body mass index (BMI) through restrictive dieting, healthy eating or unhealthy eating as well as moderating role of adolescent's weight status.

METHODS

The study was conducted in 16 public middle and high schools in Central and Eastern Poland. A sample of 1042 under- and healthy-weight white adolescents aged 13-20 (BMI: 12.63-24.89) completed two self-reported questionnaires (fruit, vegetable, and energy-dense food intake) with a 11-month interval. Weight and height were measured objectively. Multiple mediation analysis and moderated multiple mediation analysis were conducted to test the study hypotheses.

RESULTS

Adolescents less satisfied with their bodies were more likely to diet restrictively and at the same time ate more unhealthy energy-dense food rather than healthy food, which in turn predicted lower BMI. No moderating effects of weight status were found.

CONCLUSIONS

Low body satisfaction is a risk for restrictive diet and unhealthy food intake. Prevention programs may target under- and healthy-weight adolescents who are highly dissatisfied with their bodies, have a high intake of energy-dense food and apply a restrictive diet at the same time.

LEVEL OF EVIDENCE

Level III: longitudinal cohort study.

Norms and Attitudes about Being an Active Bystander: Support for Telling Adults about Seeing Knives or Guns at School among Greater London Youth

A detailed understanding of the factors associated with support among youth for reporting a knife or gun at school to an adult is essential to inform violence prevention initiatives. However, no studies have empirically assessed attitudes about support for reporting among secondary school students in Greater London nor perceived norms about such support among peers. Thus, this study explores whether students misperceive peer norms about support for telling adults about seeing weapons at school. Anonymous surveys were completed by 7401 youth (52% female; 43% White; mean age 11.8 years) in school years 4-11 in 45 school cohorts in a greater London borough between 2007 and 2012. Students reported both personal support about reporting weapons to several categories of adults and whether they perceived most other students at their school to support reporting weapons to adults in each category. Most students (64-78% on average) in most cohorts personally thought that students should report seeing a weapon at school to head teachers, police/security guard, teachers/counselors, and parent/other adult relatives. However, 34-44% of students erroneously thought that the majority of their peers did not support reporting to these adults. Perceived norms predicted personal support for reporting, adjusting for the prevalence of actual support at one's school and other factors. Pervasive norm misperceptions about reporting may contribute to a less safe environment.

A Critical Appraisal of the Social Norms Approach as an Interventional Strategy for Health-Related Behavior and Attitude Change

The Social Norms Approach is a widely used intervention strategy for promoting positive health-related behaviors. The Approach operates on the premise that individuals misperceive their peers' behaviors and attitudes, with evidence of under- and over-estimations of behaviors and peer approval for a range of positive and negative behaviors respectively. The greater these misperceptions, the more likely an individual is to engage in negative behaviors such as consuming heavier amounts of alcohol and other substances and reduce positive behaviors such as eating healthily and using sun protection. However, there are many complexities associated with the use of social norms feedback in interventions and empirical studies. Many social norms interventions do not attempt to change misperceptions of social norms or measure changes in normative perceptions pre- and post-intervention. This has led to a conflation of generic social norms interventions with those that are explicitly testing the Approach's assumptions that it is misperceptions of peer norms which drive behavior. The aim of the present review was to provide a critical appraisal of the use of the Social Norms Approach as an intervention strategy for health-related behaviors, identify the current issues with its evidence base, highlight key opportunities and challenges facing the approach, and make recommendations for good practice when using the approach. There are three core challenges and areas for improved practice when using the Social Norms Approach. Firstly, improvements in the methodological rigor and clarity of reporting of 'social norms' research, ensuring that studies are testing the approach's assumption of the role of misperceptions on behaviors are differentiated from studies investigating other forms of 'social norms.' Secondly, the need for a more explicit, unified and testable theoretical model outlining the development of normative misperceptions which can be translated into interventional studies. Finally, a need for a more robust evaluation of social norms interventions in addition to randomized controlled trials, such as the inclusion of process evaluations, qualitative studies of participant experiences of social norms feedback, and alternative study designs better suited for real-world public health settings. Such improvements are required to ensure that the Social Norms Approach is adequately tested and evaluated.

Gender-Specific Body Areas Satisfaction and Body Weight Status in Adolescents: Mediating Effects of Physical Activity, Fruit and Vegetable Intake, and Energy-Dense Food Intake

Background

Body satisfaction is one of the key modifiable cognitive determinants of eating behaviours, physical activity, and body mass index (BMI). As the sociocultural models suggest, low body satisfaction may explain unhealthy eating and exercise behaviours. Importantly, body satisfaction levels and body areas that individuals focus on vary across genders. This study aims at investigating links between the global index of body areas satisfaction (BAS), gender‐specific BAS, fruit and vegetable (F&V) intake, energy‐dense foods intake, moderate‐to‐vigorous physical activity (MVPA), and BMI.

Methods

In all, 1,254 adolescents completed questionnaires and had their weight and height objectively measured with 2‐ and 13‐month follow‐ups. Indirect effects of three indices of BAS were tested in three models (male‐specific BAS amongst boys; female‐specific BAS amongst girls; the global BAS index in the total sample).

Results

Higher levels of all three BAS indices indirectly predicted lower BMI, with higher MVPA mediating this effect. In addition, higher energy‐dense foods intake mediated higher global BAS–higher BMI relationship in the total sample. Thus, the global index of BAS acts as double‐edged sword, predicting both higher MVPA and energy‐dense foods intake.

Conclusion

BAS may operate in a complex manner, predicting behaviours which may have opposite effects on BMI.

Actual Versus Perceived HIV Testing Norms, and Personal HIV Testing Uptake: A Cross-Sectional, Population-Based Study in Rural Uganda

HIV testing is an essential part of treatment and prevention. Using population-based data from 1664 adults across eight villages in rural Uganda, we assessed individuals' perception of the norm for HIV testing uptake in their village and compared it to the actual uptake norm. In addition, we examined how perception of the norm was associated with personal testing while adjusting for other factors. Although the majority of people had been tested for HIV across all villages, slightly more than half of men and women erroneously thought that the majority in their village had never been tested. They underestimated the prevalence of HIV testing uptake by 42 percentage points (s.d. = 17 percentage points), on average. Among men, perceiving that HIV testing was not normative was associated with never testing for HIV (AOR = 2.6; 95% CI 1.7-4.0, p < 0.001). Results suggest an opportunity for interventions to emphasize the commonness of HIV testing uptake.

Association between distorted body image and changes in weight status among normal weight preadolescents in Japan: a population-based cohort study

BACKGROUND

Distorted body image may be important risk factors for being underweight and overweight. The objective of this study was to investigate the association between having a distorted body image and being overweight or underweight among normal weight preadolescents in a population-based cohort study in Japan for each sex.

METHODS

The study participants were 1431 normal weight fourth-grade students (age range: 9-10 years) in Ina town, Japan from 2002 to 2007. The height and weight of each student were measured while they were in the fourth grade (at baseline) and seventh grade (3 years later). Childhood underweight and overweight were defined using the body mass index cut-off points proposed by the International Obesity Task Force. Information regarding the self-perceived weight status of each student at baseline was collected using a self-administered questionnaire. Children who were normal weight but perceived themselves as heavy or thin were regarded as having a distorted body images. A logistic regression model was used to calculate the odds ratios (ORs) and 95 % confidence interval (95 % CI) for being overweight or underweight 3 years later among those having a distorted body image at baseline.

RESULTS

Both boys and girls who perceived themselves to be heavy at baseline were at a statistically significantly greater risk of being overweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: adjusted OR: 4.66, 95 % CI: 1.01-21.48; girls: 3.88, 1.56-9.65). Both boys and girls who perceived oneself to be thin at baseline were at a statistically significantly greater risk of bring underweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: 5.51, 2.20-13.80; girls: 2.93, 1.40-6.11).

CONCLUSION

The results of the present study suggest that having a distorted body image in preadolescence is associated with being overweight or underweight in adolescence, among boys and girls, separately. Therefore, education regarding self-perceived weight could be important to help prevent underweight and overweight/obesity among preadolescent boys and girls in Japan.

Am I Overweight? A Longitudinal Study on Parental and Peers Weight-Related Perceptions on Dietary Behaviors and Weight Status Among Adolescents

OBJECTIVE

An investigation of the interplay between various types of adolescents' perceptions of weight status in predicting adolescents' nutrition behavior and their body mass was conducted. In particular, it was hypothesized that the relationship between parental and peers' perceptions of their own weight status (reported by adolescents) and objectively measured weight status of adolescents would be mediated by three types of adolescents' weight status perceptions (adolescents' own weight perceptions, parental perceptions of adolescents' weight status perceived by participants, and peers' perceptions of adolescents' weight status perceived by participants) and by adolescents' nutrition behaviors.

DESIGN

Data were collected twice, with a 13-month follow-up. Participants (N = 1096) were aged 14-20, with BMI ranging from 16.20 to 41.21. Multiple mediation analysis with two sequential mediators was applied.

MAIN OUTCOME MEASURES

At the baseline adolescents completed the questionnaire assessing their nutrition behaviors and weight status perceptions. Weight and height were measured objectively at baseline and follow-up.

RESULTS

Two types of weight perceptions (adolescents' own weight status perceptions, peers' perceptions of adolescents' weight status reported by participants), and adolescents' nutrition behaviors mediated the relationship between the others' own weight perceptions and adolescents' weight status. No indirect effects of others' own weight perceptions on adolescents' weight status through parental perceptions were found.

CONCLUSION

Adolescents' nutrition behaviors and body weight status depend on what they think about their own weight status and what they think of their peers' perceptions, but do not depend on what adolescents think of their parents' perceptions.

Misperception of peer weight norms and its association with overweight and underweight status among adolescents

Previous research has revealed pervasive misperceptions of peer norms for a variety of behaviors among adolescents such as alcohol use, smoking, and bullying and that these misperceptions are predictors of personal behavior. Similarly, misperception of peer weight norms may be a pervasive and important risk factor for adolescent weight status. Thus, the comparative association of actual and perceived peer weight norms is examined in relation to personal weight status. Secondary school students in 40 middle and high schools (n = 40,328) were surveyed about their perceptions of the peer weight norm for same gender and grade within their school. Perceived norms were compared to aggregate self-reports of weight for these same groups. Overestimation of peer weight norms by more than 5 % occurred among 26 % of males and 20 % of females (by 22 and 16 lb on average, respectively). Underestimation occurred among 38 % of males as well as females (by 16 and 13 lb on average, respectively). Personal overweight status based on body mass index (BMI) was much more prevalent among respondents who overestimated peer weight norms as was personal underweight status among respondents who underestimated norms. Perception of the peer norm was the strongest predictor of personal BMI among all personal and school variables examined for both male and female students. Thus, reducing misperceived weight norms should be given more attention as a potential avenue for preventing obesity and eating disorders.

Weight perception and its association with socio-demographic and health-related factors among Korean adolescents

BACKGROUND

Adolescence is a time of rapid growth with dramatic changes in physical appearance. The body image established at this time could affect their physical and mental health throughout their entire life. However, adolescents sometimes perceive themselves as underweight or overweight irrespective of actual weight status. The purpose of the present study was to examine the extent of weight misperception for Korean adolescents, to explore socio-demographic factors associated with weight misperception, and to examine gender-specific differences in the relationships between weight misperception and health-related factors.

METHODS

We selected data on 3321 adolescents aged 12-18 years from the five-year Korea Health and Nutrition Examination Survey (KNHANES) datasets (2007-2011). Self-perceived weight status was compared with measured weight status by cross-tabulation. The generalized logit model was used to explore the socio-demographic factors associated with weight misperception, and separate logistic regression models were fitted to examine gender-specific differences in the relationships between weight misperception and health-related factors.

RESULTS

Overall, 25.8 % of boys (overestimation 17.1 %; underestimation 8.6 %) and 29.3 % of girls (overestimation 24.0 %; underestimation 5.3 %) misclassified their weight status according to the objective standards. Weight overestimation was particularly prominent among underweight girls. Weight misperception was associated with socio-demographic factors such as gender, age, BMI, place of residence, and maternal education level. Weight overestimation and underestimation in boys and weight overestimation in girls were significantly related to inappropriate weight control practice. However, weight underestimation in girls seems to be negatively linked to inappropriate weight control practice.

CONCLUSIONS

Based on the results of the present study, comprehensive intervention programs for adolescents and their parents could be devised to raise self-awareness of their weight status, to overcome weight misperception, and to prevent obesity and its related health risks.

Personality moderates the links of social identity with work motivation and job searching

Work motivation is critical for successful school-to-work transitions, but little is known about its determinants among labor market entrants. Applying a social identity framework, we examined whether work motivation and job searching are social-contextually determined. We expected that some job seekers are more sensitive to contextual influence, depending on their personality. Mediation analyses on 591 Dutch vocational training students indicate that the perception of more positive work norms in someone's social context was related to higher levels of intrinsic motivation, which in turn predicted higher preparatory job search behavior and job search intentions. Multi-group analysis shows that perceived work norms more strongly predict work motivation among overcontrollers compared to resilients and undercontrollers. In conclusion, work motivation and job searching appear contextually determined: especially among those sensitive to contextual influence, people seem to work when they believe that is what people like them do.

Trends in thinness prevalence among adolescents in ten European countries and the USA (1998-2006): a cross-sectional survey

OBJECTIVE

To describe the prevalence of 'graded thinness' in children aged 11, 13 and 15 years in eleven developed countries and to identify trends in the prevalence of 'thinness' (BMI < 17 kg/m2 at age 18 years) by age and gender.

DESIGN

Cross-sectional study using data collected through self-reported questionnaires.

SETTING

Data were taken from the 1997/1998, 2001/2002 and 2005/2006 surveys of the Health Behaviours in School-aged Children (HBSC) Study.

SUBJECTS

Children and adolescents from ten European countries and the USA (n 158 000).

RESULTS

Prevalence of grades 1, 2 and 3 of thinness was higher among 11-year-old students compared with the 13- and 15-year-olds in all countries. A higher prevalence of thinness was observed in girls than in boys. Since 1998 the prevalence of thinness decreased steadily in Czech boys and girls, while it increased for French girls. In the total European sample of females, thinness decreased from 1998 to 2006 (χ 2 for trend, P < 0·01). Age-adjusted logistic regression analysis showed that Czech boys and girls, and Flemish and American girls were less likely to be thin in 2006 than in 1998; while a noteworthy increment, even if borderline significant, was observed for French girls with a 41% increase in the likelihood to be thin.

CONCLUSIONS

Our findings suggest that thinness is an important overlooked phenomenon with wide variation in prevalence and trends across developed countries. It deserves further longitudinal studies in a multinational context that could increase the understanding of the factors associated with thinness and contribute to developing preventive and nutritional programmes targeted at controlling obesity and chronic diseases, while monitoring thinness.

Weight misperception and health risk behaviors in youth: the 2011 US YRBS

OBJECTIVES

To evaluate dose-response associations between misperceived weight and 32 health risk behaviors in a nationally representative sample of US adolescents.

METHODS

Participants included 13,864 US high school students in the 2011 Youth Risk Behavior Survey. Comparing the degree of agreement between perceived and reported actual weight, weight misperception was determined as 5 categories. Multivariable-adjusted logistic regression analyses evaluated associations of weight misperception with 32 health risk behaviors.

RESULTS

Both underestimated and overestimated weight were statistically significantly associated with all 32 health risk behaviors in a dose-response manner after adjustment for age, sex and race/ethnicity, where greater weight misperception was associated with higher engagement in health risk behaviors.

CONCLUSIONS

Understanding potential impacts of weight misperception on health risk behaviors could improve interventions that encourage healthy weight perception and attainment for adolescents.

Weight misperception and its association with dieting methods and eating behaviors in South Korean adolescents

BACKGROUND/OBJECTIVES

There is little information on the association between weight misperception and eating behavior in Korean adolescents. Therefore, we investigated the association of food intake habits and dieting method and disturbed eating behavior (DEB) in relation to weight misperception.

SUBJECTS/METHODS

Data was collected by using a nationwide online panel survey from 6,943 adolescents enrolled in middle/high school. DEB was measured with the Eating Attitudes Test (EAT-26) and those who scored ≥ 20 on the EAT-26 were considered to have eating disorder. Logistic regressions were conducted to examine the association between weight misperception based on self-reported weight status and dieting method and eating behaviors.

RESULTS

The proportion of weight underestimation was 23.5% and that of overestimation was 24.0%. Weight overestimating girls were more likely to engage in various unhealthy dieting practices (OR = 1.69 for fasting; OR = 1.88 for laxative or diuretic use; OR = 2.05 for self-induced vomiting after meals; P < 0.05). Moreover, there was a strong association between overestimation and undesirable eating behaviors, especially among girls, e.g.: having breakfast (OR = 0.85), high consumption of fast foods (OR = 1.28) and regular sodas (OR = 1.39), but not among boys. In both genders, weight overestimation appears to be a major risk factor for DEB (OR = 1.34 for boys and OR = 1.41 for girls; P < 0.05).

CONSLUSIONS

Weight overestimation is associated with unhealthy weight control practices and eating behaviors. We particularly found a significant association between weight overestimation and DEB among nationwide Korean adolescents.

Peer similarity and influence for weight-related outcomes in adolescence: a meta-analytic review

Weight-related problems, including obesity and disordered eating, have emerged as major public health concerns for adolescents. To address these deviations from healthy eating and weight regulation, prevention and intervention efforts have targeted the influence of peers. Yet, evidence that peers influence weight-related outcomes, often inferred from similarity among peers, is inconsistent. This meta-analytic review evaluated peer similarity and influence not only for body size and symptoms of disordered eating, but also for key determinants of obesity (food intake and physical activity levels) and eating pathology (body dissatisfaction and weight control strategies). For each of the six outcomes, data was summarized from 9 to 24 independent studies. Results revealed significant, non-trivial similarity among peers across outcome variables, with the exception of disordered eating. Findings indicated that resemblances among peers were unlikely to be solely the reflection of cognitive biases or the selection of alike friends, but may be partially due to influence. To better understand the influence of peers, further longitudinal research is needed, particularly focusing on the factors that moderate susceptibility to conformity.

Being Normal Weight but Feeling Overweight in Adolescence May Affect Weight Development into Young Adulthood-An 11-Year Followup: The HUNT Study, Norway

Objectives. To explore if self-perceived overweight in normal weight adolescents influence their weight development into young adulthood and if so, whether physical activity moderates this association. Methods. A longitudinal study of 1196 normal weight adolescents (13-19 yrs) who were followed up as young adults (24-30 yrs) in the HUNT study. Lifestyle and health issues were assessed employing questionnaires, and standardized anthropometric measurements were taken. Chi square calculations and regression analyses were performed to investigate the associations between self-perceived overweight and change in BMI or waist circumference (WC) adjusted for age, age squared, sex, and other relevant cofactors. Results. Adolescents, defined as being normal weight, but who perceived themselves as overweight had a larger weight gain into young adulthood than adolescents who perceived themselves as normal weight (difference in BMI: 0.66 units [CI95%: 0.1, 1.2] and in WC: 3.46 cm [CI95%: 1.8, 5.1]). Level of physical activity was not found to moderate this association. Conclusions. This study reveals that self-perceived overweight during adolescence may affect development of weight from adolescence into young adulthood. This highlights the importance of also focusing on body image in public health interventions against obesity, favouring a "healthy" body weight taking into account natural differences in body shapes.

Using social norms to reduce bullying

Bullying attitudes and behaviors and perceptions of peers were assessed in a case study experiment employing a social norms intervention in five diverse public middle schools in the State of New Jersey (Grades 6 to 8). Data were collected using an anonymous online survey (baseline n = 2,589; postintervention n = 3,024). In the baseline survey, students substantially misperceived peer norms regarding bullying perpetration and support for probullying attitudes. As predicted by social norms theory, they thought bullying perpetration, victimization, and probullying attitudes were far more frequent than was the case. Also as predicted, variation in perceptions of the peer norm for bullying was significantly associated with personal bullying perpetration and attitudes. Using print media posters as the primary communication strategy, an intervention displaying accurate norms from survey results was conducted at each of the five school sites. A pre-/postintervention comparison of results revealed significant reductions overall in perceptions of peer bullying and probullying attitudes while personal bullying of others and victimization were also reduced and support for reporting bullying to adults at school and in one’s family increased. The extent of reductions across school sites was associated with the prevalence and extent of recall of seeing poster messages reporting actual peer norms drawn from the initial survey data. Rates of change in bullying measures were highest (from around 17% to 35%) for the school with the highest message recall by students after a one-and-a-half-year intervention. Results suggest that a social norms intervention may be a promising strategy to help reduce bullying in secondary school populations.