Adolescents' Responses to a School-Based Prevention Program Promoting Healthy Eating at School

Boys and girls differ in their rationale behind eating: a systematic review of intrinsic and extrinsic motivations in dietary habits across countries

Background

Boys' and girls' food habits diverge in adolescence (13-18 years). This contributes to unequal risks of adverse health outcomes based on sex and gender in adulthood (e.g., heart diseases in men vs. disorder eating in women). Though multi-factorial, why these dietary differences occur is unclear.

Purpose

To identify the reasons why adolescents' motivation behind dietary habits differs among genders.

Methods

Four databases were searched following PRISMA guidelines. Eligible studies had to use qualitative methodology and report at least one gender unique theme. Reported themes were thematically analyzed, with a sub-analysis by country where the studies were conducted. Quality appraisals were assessed using the Critical Appraisal Skills Programme checklist.

Results

In the 34 eligible articles (n = 1,694 returned) two overarching themes emerged that dictated dietary habits in adolescents: Self-motivators and Uncontrollable factors. Gender differences arose whereby girls highlighted more external motivators (e.g., eat healthier, change dietary habits around boys and be thin to fit traditional norms) over their dietary habits. In contrast, boys focused on more internal motivators (e.g., gain autonomy, eat for enjoyment and pursue gains in physical performance). This suggests that motivation underlying how boys and girls eat differs. These trends were largely consistent across countries.

Conclusion

Boys' and girls' food habits are not motivated by the same factors. To create more effective dietary interventions targeting health promotion, unique motivations behind food habits need to be understood and incorporated.

Systematic review registration

Identifier: CRD42022298077.

The Association between Melatonin-Containing Foods Consumption and Students' Sleep-Wake Rhythm, Psychoemotional, and Anthropometric Characteristics: A Semi-Quantitative Analysis and Hypothetical Application

Food is an important source of melatonin (MT), which belongs to a group known as chronobiotics, a class of substances that affect the circadian system. Currently, no studies have been conducted on how the consumption of foods containing MT (FMT) is associated with indicators characterizing the human circadian system. In this study, we tested the hypothesis that FMT consumption is associated with chronotype and social jetlag. A total of 1277 schoolchildren and university students aged M (SD) 19.9 (4.1) years (range: 16-25 years; girls: 72.8%) participated in a cross-sectional study. Each participant completed an online questionnaire with their personal data (sex, age, height, weight, waist circumference, and academic performance) and a sequence of tests to assess their sleep-wake rhythm (the Munich Chronotype Questionnaire), sleep quality (the Pittsburgh Sleep Quality Index), and depression level (the Zung Self-Rating Depression Scale). Study participants also completed a modified food frequency questionnaire that only included foods containing MT (FMT). They were asked how many foods containing MT (FMT) they had eaten for dinner, constituting their daily serving, in the past month. The consumption of foods containing MT (FMT) during the day (FMTday) and at dinner (FMTdinner) was assessed using this test. Multiple regression analyses were performed to assess the association between the studied indicators. We found that higher FMTday values were associated with early chronotype (β = -0.09) and less social jetlag (β = -0.07), better sleep quality (β = -0.06) and lower levels of depression (β = -0.11), as well as central adiposity (β = -0.08). Higher FMTdinner values were associated with a lower risk of central adiposity (β = -0.08). In conclusion, the data obtained confirm the hypothesis that the consumption of foods containing MT (FMT) is associated with chronotype and social jetlag in adolescents and young adults.

How (Un-)Healthy are Austrian school food environments? Evidence from focus groups and citizen science

BACKGROUND

Adolescents face high-choice school food environments that offer plenty of highly processed foods. Processed food producers target young people in their marketing, but there is limited data on the actual food supply inside and in the vicinity of Austrian schools and its impact on adolescent food choices. This study employs an innovative mixed-methods approach to explore adolescents' food choices.

METHODS

In Study 1, we conducted a citizen science study, with students as volunteer scientists. The students examined the food supply in and around their schools according to the Austrian food pyramid and categorized 953 food items in 144 food suppliers using photographs and descriptions. In Study 2, we explored students' food preferences in focus groups. We conducted four focus groups at four different schools in Tyrol, with 25 students (11 male, 14 female) between the ages of 12 and 15. We then linked the findings on individual preferences with the documented supply.

RESULTS

Study 1 found that the food supply in the investigated schools was predominantly categorized as unhealthy. The students categorized 46% as "unhealthy", 32% as "intermediate", and only 22% as "healthy". Study 2 identified three influential factors in students' food choices: 1) individual factors (such as taste and preferences), 2) social factors (such as mingling with peers), and 3) structural factors (such as physical environment and accessibility).

CONCLUSION

The study shows that unhealthy products cater to unhealthy preferences among adolescents and dominate current school food environments. Policies need to address unhealthy school food environments to address this issue. For instance, food supplies should be presented in an attractive ways, in fun places where students can mingle and express their identities.

Improving adolescents' dietary behaviours in the school-setting: challenges and opportunities

Adolescence is a critical time of physical, psychological and social development, and thus, optimal nutritional intakes are required during this life stage. Despite this, adolescence is recognised as a period of nutritional vulnerability, with many reportedly failing to meet current dietary guidelines. The school-setting presents a favourable environment to intervene and promote positive dietary behaviours and is also inclusive regardless of socio-economic status. However, a lack of consensus exists on how best to utilise schools to facilitate improvements in dietary behaviours among this age group. Whilst previous research has focused on identifying the factors motivating dietary choices within the school-setting, less is known on the optimum strategies to enhance these dietary choices which could positively contribute to the design of future interventions. It is reported that adolescents have good nutritional knowledge, although this does not appear to be a central consideration when making their dietary choices. Alternative factors at the individual (taste, visual appeal, familiarity, food quality, price, portion size, value for money, time/ convenience), social (peer influence), physical (product placement) and macro environment (food availability) levels have been frequently cited as important influences on adolescents' dietary choices in school. Although school-based interventions have shown potential in achieving positive dietary change among adolescents, more research is needed to determine the most effective methods in improving dietary behaviours in schools. This review summarises the key factors which influence adolescents' school-based dietary choices and the effectiveness of previously conducted interventions, identifying promising components for consideration when developing future dietary interventions within the school-setting.

Analysis of Association between Adolescents' Food Habits and Body Mass Change in a Population-Based Sample: Diet and Activity of Youth during COVID-19 (DAY-19) Study

The COVID-19 pandemic may have contributed to food habit changes, including some negative ones that may increase the risk of overweight and obesity. The aim of the study was to analyze the association between adolescents' food habits, body mass change, as well as physical activity level in a population-based sample within the Diet and Activity of Youth during COVID-19 (DAY-19) Study. The DAY-19 Study was conducted in a cohort of 1333 students (aged 10-16 years) recruited in schools after stratified random quota sampling of primary schools (sampling counties within voivodeships and schools within counties) in June 2020. The food habits were assessed for the period of the COVID-19 pandemic and the period before the COVID-19 pandemic while using Adolescent Food Habits Checklist (AFHC). The body mass changes were assessed based on body weight and height for the period of the COVID-19 pandemic and the period before the COVID-19 pandemic while using Polish growth reference values. The physical activity changes were assessed based on the subjective assessment of adolescents. It was stated that for female adolescents declaring body mass gain during the COVID-19 pandemic the highest AFHC purchase scores (healthy purchase habits) (p < 0.0001) were accompanied by the lowest AFHC consumption score (unhealthy consumption habits) (p < 0.0001), as well as for female adolescents declaring physical activity decrease during the COVID-19 pandemic the highest AFHC purchase scores (healthy purchase habits) were observed (p = 0.0333). It was stated that for male adolescents declaring physical activity increased during the COVID-19 pandemic, the highest AFHC consumption scores (healthy consumption habits) were observed (p = 0.0003). In the case of a majority of participants, the general food habits were unchanged, which was observed mainly for food habits associated with food preparation. More food habits changes associated with the COVID-19 pandemic resulting in body mass changes were observed in females than in male adolescents. Body mass gain during the COVID-19 pandemic in adolescents may have resulted from unhealthy consumption habits, accompanied by decreased physical activity, in spite of the fact that this sub-group presented healthy purchase habits, which was observed especially for female adolescents.

Health behaviours as predictors of the Mediterranean diet adherence: a decision tree approach

OBJECTIVE

This study aimed to identify health behaviours that determine adolescent's adherence to the Mediterranean diet (MD) through a decision tree statistical approach.

DESIGN

Cross-sectional study, with data collected through a self-fulfilment questionnaire with five sections: (1) eating habits; (2) adherence to the MD (KIDMED index); (3) physical activity; (4) health habits and (5) socio-demographic characteristics. Anthropometric and blood pressure data were collected by a trained research team. The Automatic Chi-square Interaction Detection (CHAID) method was used to identify health behaviours that contribute to a better adherence to the MD.

SETTING

Eight public secondary schools, in Algarve, Portugal.

PARTICIPANTS

Adolescents with ages between 15 and 19 years (n 325).

RESULTS

According to the KIDMED index, we found a low adherence to MD in 9·0 % of the participants, an intermediate adherence in 45·5 % and a high adherence in 45·5 %. Participants that regularly have breakfast, eat vegetable soup, have a second piece of fruit/d, eat fresh or cooked vegetables 1 or more times a day, eat oleaginous fruits at least 2 to 3 times a week, and practice sports and leisure physical activities outside school show higher adherence to the MD (P < 0·001).

CONCLUSIONS

The daily intake of two pieces of fruit and vegetables proved to be a determinant health behaviour for high adherence to MD. Strategies to promote the intake of these foods among adolescents must be developed and implemented.

'We know what we should eat but we don't …': a qualitative study in Irish secondary schools

Healthy eating opportunities for young people need to be provided in the school setting. Links between formal education and local policies and practices, and active involvement of students are emphasized in whole school approaches to health promotion. In many jurisdictions, schools struggle to provide nutritious food that is acceptable to students. The aim of this study was to conduct an in-depth exploration of school food and students' food choice with students, teachers and principals in six Irish secondary schools. Students conducted their own focus groups with peers, and a researcher conducted focus groups with teachers and one-to-one interviews with principals. Students, teachers and principals expressed dissatisfaction with food provision within their respective schools and reported unhealthy dietary behaviours among the student body as the norm. Divergent views, however, emerged regarding education, knowledge and the primary drivers of food choice. Teachers and principals saw a role for more education modules and students believed environmental infrastructures, practices and policies needed to be addressed to improve behaviours. This consultation with students, teachers and principals highlight that, in addition to education, the social and environmental aspects of food choice and eating at school deserve attention in future research and policy.

Dynamics of the complex food environment underlying dietary intake in low-income groups: a systems map of associations extracted from a systematic umbrella literature review

Background

Inequalities in obesity pertain in part to differences in dietary intake in different socioeconomic groups. Examining the economic, social, physical and political food environment of low-income groups as a complex adaptive system – i.e. a system of multiple, interconnected factors exerting non-linear influence on an outcome, can enhance the development and assessment of effective policies and interventions by honouring the complexity of lived reality. We aimed to develop and apply novel causal loop diagramming methods in order to construct an evidence-based map of the underlying system of environmental factors that drives dietary intake in low-income groups.

Methods

A systematic umbrella review was conducted on literature examining determinants of dietary intake and food environments in low-income youths and adults in high/upper-middle income countries. Information on the determinants and associations between determinants was extracted from reviews of quantitative and qualitative studies. Determinants were organised using the Determinants of Nutrition and Eating (DONE) framework. Associations were synthesised into causal loop diagrams that were subsequently used to interpret the dynamics underlying the food environment and dietary intake. The map was reviewed by an expert panel and systems-based analysis identified the system paradigm, structure, feedback loops and goals.

Results

Findings from forty-three reviews and expert consensus were synthesised in an evidence-based map of the complex adaptive system underlying the food environment influencing dietary intake in low-income groups. The system was interpreted as operating within a supply-and-demand, economic paradigm. Five sub-systems (‘geographical accessibility’, ‘household finances’, ‘household resources’, ‘individual influences’, ‘social and cultural influences’) were presented as causal loop diagrams comprising 60 variables, conveying goals which undermine healthy dietary intake.

Conclusions

Our findings reveal how poor dietary intake in low-income groups can be presented as an emergent property of a complex adaptive system that sustains a food environment that increases the accessibility, availability, affordability and acceptability of unhealthy foods. In order to reshape system dynamics driving unhealthy food environments, simultaneous, diverse and innovative strategies are needed to facilitate longer-term management of household finances and socially-oriented practices around healthy food production, supply and intake. Ultimately, such strategies must be supported by a system paradigm which prioritises health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01164-1.

What Do Secondary Schools Need to Create Healthier Canteens? The Development of an Implementation Plan

Introduction: The Netherlands Nutrition Centre developed guidelines to improve the availability and accessibility of healthier food products in Dutch canteens. This paper describes the development of an implementation plan to facilitate implementation of Guidelines for Healthier Canteens in Dutch secondary schools. Materials and Methods: In cooperation with stakeholders (i.e., school/caterer managers/employees, school canteen advisors, researchers) and based on theory, we developed an implementation plan in three steps. First, we identified factors that impede/facilitate stakeholders to create a healthier school canteen during 14 interviews. Second, 25 experts discussed and prioritized these identified factors in an expert meeting. Third, we translated these factors into tools to be included in the implementation plan, by making use of behavior change taxonomies and evidence-based implementation strategies. Results: The plan aims to support stakeholders in implementing healthier school canteens and consists of five tools: (1) tailored advice based on an online questionnaire to assess schools' and stakeholders' context and the Canteen Scan (i.e., an online tool to assess the availability and accessibility of food/drink products); (2) communication materials with information and examples; (3) online community for support by sharing experiences/questions; (4) digital newsletter as reminder/support; (5) fact sheet with students' needs/wishes to tailor the canteen. Discussion: This study illustrates how collaboration between science, policy and practice resulted in a tailored implementation plan aimed to support schools to adhere to school canteen policy. This development serves as a good example for researchers, health promotion policymakers, and practitioners how to create an implementation plan that fits the needs of stakeholders.

The impact of, and views on, school food intervention and policy in young people aged 11-18 years in Europe: A mixed methods systematic review

Understanding the social and environmental influencers of eating behaviours has the potential to improve health outcomes for young people. This review aims to explore the effectiveness of school nutrition interventions and the perceptions of young people experiencing a nutrition focused intervention or change in school food policy. A comprehensive systematic search identified studies published between 1 December 2007 to 20 February 2020. Twenty-seven studies were included: 22 quantitative studies of nutrition related outcomes and five qualitative studies reporting views and perceptions of young people (combined sample of 22,138 participants, mean ages 12-18 years). The primary outcome was nutrition knowledge/dietary behaviours, with secondary outcomes exploring body mass index (BMI) and wellbeing. Due to the heterogeneity of studies, a narrative results description is presented. The findings demonstrate that school nutrition programmes can be effective in reducing sugar, sugar sweetened beverages (SSB) and saturated fat and increasing fruit and vegetable (FV) intake. The lived experiences of young people in a school context provide valuable insights that should be considered in the development of effective school food policy and interventions. This review affirms the significant role that schools can play in supporting good nutrition in all young people and provides opportunities to inform the school food agenda.

Dutch Preadolescents' Food Consumption at School: Influence of Autonomy, Competence and Parenting Practices

Eating habits appear to become less healthy once children move into adolescence. Adolescence is characterized by increasing independence and autonomy. Still, parents continue influencing adolescents' eating habits. This cross-sectional study used a Self-Determination Theory perspective to examine how parents can support preadolescents' food-related autonomy and competence and how these factors are associated with healthy eating motivation and food consumption at school. In addition, the effect of relative healthy food availability at home on preadolescents' food consumption at school was explored. In total, 142 Dutch preadolescents (mean age 12.18) and 81 parents completed questionnaires. The results showed that preadolescents perceived themselves as having higher food-related autonomy and lower competence to eat healthily as compared to their parents' perceptions. A path analysis was conducted to test the hypothesized model. Although parental support was positively associated with food-related autonomy, higher food-related autonomy was related to less healthy food intake at school. On the other hand, competence to eat healthily indirectly affected preadolescents' healthy intake ratio through their healthy eating motivation. Finally, the relative availability of healthy options at home was positively associated with preadolescents' healthy intake ratio outside the home. Findings from the study advance the understanding of individual and environmental factors that influence eating habits during the key life period of early adolescence. The results may inform interventions aiming to guide preadolescents to make healthy food choices on their own.

ANTHROPOMETRIC MEASUREMENTS, DIETARY HABITS, SERUM LIPID AND GLUCOSE LEVELS IN RELATION TO HIGH BLOOD PRESSURE AMONG ADOLESCENT BOYS AND GIRLS IN CROATIA

The aim was to determine differences in anthropometric measurements, dietary habits, serum lipid and glucose levels in relation to high blood pressure (BP) among adolescent boys and girls in Croatia. The specific aim was to determine the effect of dietary habits and lifestyle on high BP in adolescents according to sex. The study included 260 (68.2%) adolescent girls and 121 (31.8%) boys with anthropometric data obtained (without missing values) from 246 girls and 111 boys. Participants answered questions from the questionnaire and anthropometric BP and blood test values were obtained. Non-parametric tests were used in analyses of reference intervals of systolic and diastolic BP in adolescent boys and girls according to age. High BP was defined as ≥90^th percentile for adolescent girls and boys, with a value of ≥135/87.5 mm Hg. Mann-Whitney U test was used to analyze differences in anthropometric and laboratory values between the groups of girls and boys with high (≤90^th percentile) and normal BP. Increase in systolic and diastolic BP was noted in the adolescents. In girls, BP values showed a decreasing systolic and increasing diastolic BP trend with age. Girls with high BP had a significantly higher body mass index (BMI) (p=0.020), waist circumference (WC) (p=0.002), waist-to-height ratio (WHtR) (p=0.016), waist-to-hip ratio (WHR) (p=0.043), hip circumference (HC) (p=0.015), triglyceride (TG) levels (p=0.021), higher prevalence of unhealthy diet at school breakfast (p=0.008) and lower prevalence of eating fish (p=0.02). Boys with high BP had a significantly higher BMI (p=0.045), WC (p=0.004), WHtR (p=0.017), WHR (p=0.022) and higher prevalence of eating meat products (p=0.015). Effective health interventions are needed to reduce the risk of developing cardiovascular diseases and preventing age-related illness.

The Effect of Supportive Implementation of Healthier Canteen Guidelines on Changes in Dutch School Canteens and Student Purchase Behaviour

We developed an implementation plan including several components to support implementation of the "Guidelines for Healthier Canteens" in Dutch secondary schools. This study evaluated the effect of this plan on changes in the school canteen and on food and drink purchases of students. In a 6 month quasi-experimental study, ten intervention schools (IS) received support implementing the guidelines, and ten control schools (CS) received only the guidelines. Changes in the health level of the cafeteria and vending machines were assessed and described. Effects on self-reported purchase behaviour of students were analysed using mixed logistic regression analyses. IS scored higher on healthier availability in the cafeteria (77.2%) and accessibility (59.0%) compared to CS (60.1%, resp. 50.0%) after the intervention. IS also showed more changes in healthier offers in the cafeteria (range -3 to 57%, mean change 31.4%) and accessibility (range 0 to 50%, mean change 15%) compared to CS (range -9 to 46%, mean change 9.7%; range -30 to 20% mean change 7% resp.). Multi-level logistic regression analyses on the intervention/control and health level of the canteen in relation to purchase behaviour showed no relevant relations. In conclusion, the offered support resulted in healthier canteens. However, there was no direct effect on students' purchase behaviour during the intervention.

Adolescents' Food Purchasing Patterns in The School Food Environment: Examining the Role of Perceived Relationship Support and Maternal Monitoring

The school food environment plays a role in adolescents’ dietary behaviors. In this study, adolescents’ food purchasing patterns in and around school and its potential relationship with perceived maternal relationship support and maternal monitoring were examined. Data were collected in The Netherlands in 2017. A total of 726 adolescents (45.8% boys; M_age = 13.78 ± 0.49) and 713 mothers (M_age = 45.05 ± 4.45) participated. Adolescents’ frequency of bringing and purchasing foods was assessed via a Food Frequency Questionnaire (FFQ). Relationship support and monitoring were measured via self-report questionnaires. Structural Equation Modelling (SEM) was conducted to examine associations between adolescents’ food purchasing patterns, relationship support, and monitoring. Results indicated that adolescents brought food and drinks mostly from home, and infrequently purchased these products in and around school. Yet, differences exist between subgroups of adolescents. Relationship support was positively associated with bringing fruit, vegetables and salad and negatively associated with purchasing sweet snacks. No associations were found for monitoring. These findings indicate that family-home determinants of healthy and unhealthy eating are important factors to consider when examining the impact of the school food environment on adolescents’ food purchasing patterns. This has implications for policy makers who aim to develop and implement measures to improve adolescents’ eating in and around school.

Stronger State School Nutrition Laws Are Associated With Healthier Eating Behaviors and Optimal Weight Status in US Adolescents

PURPOSE

To investigate relationships of farm-to-school, school meal, and competitive food state laws with eating behaviors and weight status and to examine interaction between different types of state laws.

DESIGN

Observational cohort study.

SETTINGS

US adolescents.

PARTICIPANTS

The NEXT study is a nationally representative sample of adolescents assessed annually for 7 years. Data (N = 2751) from students attending public schools from the first (W1) and third (W3) assessment waves (2010 and 2012), occurring during grades 10 and 12, respectively, of the NEXT study were included.

MEASURES

Eating behaviors and weight status of adolescents were linked with Classification of Laws Associated with School Students scoring for state laws.

ANALYSIS

Regression analyses examined associations of laws with intake and weight status, accounting for complex survey design and school-level clustering.

RESULTS

Adolescents in states with strong farm-to-school laws had greater W1 whole fruit, lower soda, and snack intakes versus those in states with no laws. Strong school meal laws were associated with lower W1 soda intake. Adolescents in states with strong competitive food laws had lower soda intake and overweight/obesity odds than those in states with no laws in W3. Strong farm-to-school laws were inversely associated with W3 overweight/obesity odds only in states with strong competitive food laws.

CONCLUSIONS

Stronger laws governing school nutrition were related to healthier eating behaviors and optimal weight status in this nationally representative sample of adolescents. Further, farm-to-school laws may be more effective in reducing obesity when combined with strong competitive food legislation.

Development and Evaluation of the Implementation of Guidelines for Healthier Canteens in Dutch Secondary Schools: Study Protocol of a Quasi-Experimental Trial

Introduction: To encourage healthier food/drink choices, the “Guidelines for Healthier Canteens” were developed by the Netherlands Nutrition Centre. This paper describes (1) how we developed a plan to support implementation of the “Guidelines for Healthier Canteens” in Dutch secondary schools, and (2) how we will evaluate this plan on process and effect level.

Materials and Methods: The implementation plan (consisting of several tools) was developed in cooperation with stakeholders. Barriers/facilitators to implement the guidelines were identified by 14 interviews and prioritized during one expert meeting. Thereafter, these barriers were translated into implementation tools using behavioral change methods and implementation strategies. The implementation plan consists of the tools: tailored advice provided via an advisory meeting and report, based on a questionnaire about the stakeholders'/school's context and the “Canteen Scan,” an online tool to assess the product availability and accessibility; communication materials; an online community; newsletters; a factsheet with students' wishes/needs. This implementation plan will be evaluated on process and effect in a 6-month quasi-experimental controlled design with 10 intervention and 10 matched control schools. Process outcomes will be measured: (1) factors affecting implementation and (2) the quality of implementation, both collected via a questionnaire among involved stakeholders. Effect outcomes will be collected pre/post-intervention with: (1) self-reported purchase behavior among around 100 students per school; (2) the “health level” of the school canteen. Linear and linear/logistic two-level regression analyses will be performed.

Discussion: The implementation tools are developed by combining a theory and practice-based approach, with input from different stakeholders. If these tools are evaluated positive, it will support schools/stakeholders to create a healthier school canteen.

Trial Registration: Dutch Trial register no.: NTR5922, date of registration June 20, 2016; METC no.: 2015.331; EMGO+ project number: WC2015-008.