Sugar-sweetened beverage consumption among school-age adolescents in Central Catalonia: patterns and food environment influences

Laura Soler Farré

Ph.D. Health and Psychology

Thesis supervisors: Marina Bosque-Prous and Alicia Aguilar-Martínez

Member of the thesis committee: Cristina Vaqué-Crusellas

Index

Abstract and keywords

Background or State of the art

Justification of the interest of the proposal

Research questions and objectives

Research questions

Objectives

Working hypotheses

Specific Objective 1

Specific Objective 2

Specific Objective 3

Research Methodology

Means and resources

Special software or equipment

Costs associated with dissemination results

Work plan

First-year

Second-year

Third-year

Fourth-year

Fifth year

Bibliographical references

Abstract and keywords

Introduction and objectives

Adolescents are the primary consumers of sugar-sweetened beverages (SSB) worldwide, with well-documented negative impacts on health including dental problems, obesity, type 2 diabetes, and hypertension. The World Health Organization recommends reducing the intake of free sugars to less than 10% of daily energy intake to improve overall health, which means drinking less than 250ml per day of SSB without considering free sugars from food solids or semi-solids in the diet. Various factors such as media use, accessibility and availability of SSBs at home and school environments, and modeling of behavior affect SSB consumption. Efforts such as SSB taxes and warning labels have been effective in reducing SSB purchases and dietary intake. Despite the decreasing trend in SSB consumption worldwide, it is necessary to continue work in curbing daily consumption, particularly among male adolescents from the lowest socioeconomic strata. Furthermore, the lack of research on SSB consumption among adolescents in Catalonia and the potential association between SSB consumption and exposure to unhealthy food and beverages in their school environment emphasizes the importance of this research plan. It could provide valuable information on the factors influencing SSB consumption among adolescents.

The main objective is to analyze the consumption of sugar-sweetened beverages (SSB) in teenagers from Central Catalonia and related individual and contextual factors. The specific objectives are to estimate the consumption of SSB and associated factors among adolescents aged 12 to 18 in Central Catalonia during the 2021-2022 academic year, to examine consumption trends over three academic years, and to explore the relationship between the consumption of SSB and exposure to these beverages in school environments.

Methods

The methodology includes three cross-sectional studies that will be conducted using data from the Desk-Cohort project. The first study will aim to estimate the prevalence of second-wave SSB consumption and analyze the demographic and socioeconomic factors associated with it. The second study will examine trends in SSB consumption over three academic years using statistical analyses. The third study will investigate the prevalence and associated factors of third-wave SSB consumption and explore the relationship between availability and intake using contextual data on SSB availability and the school food environment.

Expected results

Our study in Central Catalonia is expected to confirm the high consumption of sugar-sweetened beverages (SSB) among adolescents, surpassing recommended levels. Lower socioeconomic positions may correlate with a higher likelihood of SSB consumption, while female adolescents may show lower SSB intake compared to males. We anticipate a decrease in SSB consumption among high school students over time, with a significant decline projected in the 2023-2024 school year. Additionally, the study may reveal the possibility of socioeconomic inequalities in the prevalence of SSB consumption among high school students increasing over time. Furthermore, the findings may indicate a higher likelihood of high school students consuming SSB above current recommendations when exposed to greater availability of unhealthy foods and beverages in their school environment.

Keywords:

Sugar-sweetened beverages; adolescents; socioeconomic position; gender inequalities, food environment, secondary school.

Background or State of the art

For many years, the consumption of sugar-sweetened beverages (SSBs) among adolescents has been a significant public health problem that requires attention. Adolescents are the largest consumers of SSBs worldwide, and the negative impact of their high consumption on health is well documented (1).

SSB are the main culprits of increased caloric intake among SSB consumers, and higher intake of SSBs is associated with dental problems (2,3) and increased risk of developing both metabolic syndrome and related diseases such as hypertension, type 2 diabetes (4), cardiometabolic risk (5), and obesity (4,6-14). However, it should be noted that not only does the total caloric intake influence SSB consumers’ health, but we also need to focus on the total intake of free sugars. The World Health Organization (WHO) published in 2015 a new recommendation to reduce the intake of free sugars to <10% of daily energy intake, with a stricter target of <5% of daily energy intake for additional health benefits. This is equivalent to less than one serving (maximum 250ml) per day of commonly consumed SSB (15). In addition, other sources of free sugars must be taken into account, such as honey, syrups or other processed solid foods with added free sugars. Thus, to improve overall health, it is important to limit the intake of all types of free sugars.

The WHO categorizes sugar-sweetened beverages (SSBs) as carbonated or non-carbonated sodas, fruit and vegetable juices and drinks, liquid and powder concentrates, flavored water, energy, and sports drinks, ready-to-drink tea and coffee, and flavored milk drinks (15). However, variations exist in the definition of SSBs used in different studies, leading to difficulties in comparing results. For instance, some studies include drinks with added sugars while others only consider sweetened beverages, omitting ready-to-drink tea and coffee, or eliminating plant-based beverages, liquid and powder concentrates, and flavored water or milk (1). Therefore, it is crucial to clarify which drinks fall under the SSB category in each investigation conducted.

Although the trend in daily SSB consumption has been decreasing worldwide (16), intake remains high according to WHO recommendations (17), the school nutrition guide of the Generalitat de Catalunya (18), and the food guide small changes to eat better of the Public Health Agency of Catalonia (ASPCAT) (19) in which they recommend that the less consumption of sugary foods and drinks the better.

Currently, China tops the list with an average intake of 710 ml/day, followed by Argentina with 628 ml/day, Mexico, Central America (Honduras, Guatemala, El Salvador…), and South America such as Brazil, Chile, Peru, and Bolivia, where adolescents consume an average of 350 ml/day (16). In Canada, Australia, and the United States, daily intake is below 250 ml with an average of 140 ml per day (16).

In Europe, consumption of soft drinks and sugar-sweetened beverages among adolescents has decreased overall, although it varies significantly between Western, Northern, and Southern regions [1]. In Spain, consumption remains high, with girls consuming an average of 191 ml/day and boys 314 ml/day (20).

There are several factors that affect SSB consumption. On the one hand, there is a clear positive association between media use (television, computer, smartphone) and SSB (in developed countries), boys consume more than girls, and those with lower socioeconomic status consume more than those with higher status (21). On the other hand, important contextual factors that drive consumption include constant accessibility and availability of SSB at home and school, as well as modeling of behavior, constraints, and norms established by parents (22), and especially interventions and/or actions taken to reduce intake, including warning labels related to the health effects of SSB, school nutrition, and pricing policies such as sugary drink taxes (23) (24).

SSB taxes introduced in jurisdictions around the world appear to have been effective in reducing purchases of SSB and dietary intake (25).

Despite the sustained and progressive impact of the special tax on SSBs in Catalonia, which resulted in a significant reduction in consumption by up to 16.7% three and a half years after its implementation (26), there is currently a lack of research on the consumption of SSBs among adolescents in Catalonia.

As a result of this measure, the total consumption of soft drinks is decreasing with a shift towards the consumption of sugar-free or reduced-sugar soft drinks instead of soft drinks that contain sugar (27).

Although the trend in SSB consumption is declining, work must continue to curb their daily consumption, especially among teenagers from lower socioeconomic groups (1).

Justification of the interest of the proposal

The proposed research plan is justified, on the one hand, by the negative impact that high SSB consumption has on health, both in relation to the total daily intake and the total intake of free sugars; taking into account that the latter cannot exceed 10%, and on the other hand, due to the lack of research on the consumption of SSB among adolescents in Catalonia and the need to continue with the efforts to curb its daily consumption, especially among male adolescents from the lowest socioeconomic strata. In addition, there is currently no information in the literature on the possible association between the consumption of sugar-sweetened beverages among secondary school students aged 12-18 in Central Catalonia and exposure to unhealthy food and beverages in their school environment. This knowledge gap highlights the importance of conducting research in this area, as it could provide valuable information on one of the factors that could influence sugary beverage consumption among adolescents.

Research questions and objectives

Research questions

• What is the trend in SSB consumption among school-aged adolescents in Central Catalonia from 2019 to 2024 by sex and age, based on data from the Desk-Cohort project?
• Is there an association between SSB consumption in adolescents and socioeconomic and health variables such as age, gender, and socioeconomic position?
• Is there a relationship between the consumption of SSB in adolescents of school age in central Catalonia and the food environment?

Objectives

Main objective:

To quantify SSB consumption among adolescents from Central Catalonia and analyze which individual and contextual factors are related to that consumption.

Specific objectives:

Specific objective 1: To estimate the consumption of SSB above recommendations in adolescents from 12 to 18 years in Central Catalonia in the academic course 2021-2022, and analyze which demographic and socioeconomic factors are related to this consumption.

Specific objective 2: To estimate the prevalence of high-school students aged from 12 to 18 years of Central Catalonia that consume SSB above the current recommendations in the academic courses 2019-2020, 2021-2022, and 2023-2024, and analyze the changes in consumption over time.

Specific objective 3: To analyze whether there is an association between the consumption of SSBs in high-school students aged from 12 to 18 years  in Central Catalonia and the exposure to unhealthy food and beverage in their school environment.

Working hypotheses

Specific Objective 1

Working Hypothesis 1: The consumption of SSB among adolescents will be above the current recommendations in this regard.

Working Hypothesis 2: Adolescents from lower socioeconomic position will have a higher consumption of SSB compared to those from higher socioeconomic position.

Working Hypothesis 3: Female adolescents will have lower consumption of SSB compared to male adolescents in Central Catalonia.

Specific Objective 2

Working Hypothesis 1: The prevalence of high-school students consuming SSB above the recommended levels will decrease over time, with the most significant decrease observed in the academic 2023-2024 course.

Working Hypothesis 2: Socioeconomic inequalities in the prevalence of SSB consumption above recommended levels among high school students have increased over time.

Specific Objective 3

Working hypothesis 1: High-school students exposed to a higher availability of unhealthy food and beverage in their school environment are more likely to consume SSBs above the current recommendations.

Research Methodology

In order to explain the methodology that will be used to address each of the objectives, this section has been divided into 3 subsections, one for each specific objective, where the relevant information is detailed.

Specific Objective 1:

Design of the study:

Cross-sectional design using data from wave 2 of the Desk-Cohort project (www.deskcohort.cat), which is a cohort study consisting in a biannual panel survey administered to high school students in Central Catalonia that aims to monitor and to analyze their health-related behavior and needs over time, with the goal of contributing to public health policies and reducing health inequalities.

Target population and sample selection:

9,265 students in Central Catalonia between the ages of 12 and 18 years old participated in the second wave of the Desk-Cohort project. Of these, 4,558 were boys and 4,707 were girls.

The study surveyed 12- to 18-year-old students from various secondary education courses (2nd and 4th of compulsory secondary education (CSE); 2nd of post-compulsory secondary education (PCSE); and 2nd of Intermediate Level Training Cycles (ILTC) in Central Catalonia during the academic year 2021-2022. Out of the 98 schools invited to participate, 85 (86.7%) agreed to participatec. Students who did not answer questions with less than 10% missing values were excluded.

Variables and instruments:

The data collection for this study involved the use of a questionnaire that gathered information on various variables related to health and its determinants. The questionnaire included questions on socio-demographic data, health status, rest and mood, food, physical activity, use of screens and technologies, substance use, relationships, and sexuality. To ensure the validity and comparability of the results obtained, the questionnaire was designed based on other similar surveys, including the ESCA, FRESC, STUDIES, CEEISCAT, SIVES, Youth Europe Questionnaire, AUDIT-C, CAST, CIUS, and WEMWBS. The questionnaire was self-administered through tablets with an internet connection, with the surveyors present in classrooms to assist. The data was collected through the Redcap system, which incorporated elements of internal and external validation and ensured flexibility in collecting unexpected responses. All the information collected was stored online to ensure the confidentiality of the data. The questionnaire lasted approximately 40 minutes and was answered anonymously. The project was approved by the Research Ethics Committee of the Universitat de Vic-Universitat Central de Catalunya (96/2919)

The dependent variable will be the consumption of SSB above the current recommendations, which was built from the answers to the question: How often do you drink soft drinks? There were seven possible responses: 1) More than once a day; 2) Once a day; 3) Between 4 and 6 times a week; 4) Between 2 and 3 times a week; 5) Once a week; 6) Between 1 and 3 times a month; 7) Never or less than once a month.

The independent variables will include socioeconomic status (perceived SEP measured by the MacArthur Scale of Subjective Social Status), gender (male/female), and the student’s course (2nd and 4th ESO (CINE 2), 2nd Baccalaureate, and Middle-Grade Training Cycles (CINE 3)).

Other exposure variables were referred to lifestyle: tobacco consumption (daily consumption), alcohol consumption (2 or 3 times per week) and physical activity (it should consist at least in 1 h a day of vigorous or moderate exercise, in compliance with the WHO recommendations)

Analysis plan:

The study will estimate the consumption of SSB among adolescents in Central Catalonia during the academic year 2021-2022, and analyze the demographic and socioeconomic factors associated with this consumption. The data collected will be analyzed using appropriate statistical techniques, such as logistic regression or chi-square tests, to determine the relationships between the dependent and independent variables. To determine the acceptable consumption of SSB will be taken into account, the recommendations of the WHO, the school nutrition guide of the Generalitatat de Catalunya, and the food guide small changes to eat better of Public Health Agency of Catalonia (ASPCAT)

First, we will describe the characteristics of the sample. After that, we will estimate the prevalence of consumption of SSB over the current recommendations and its 95 % confidence intervals (CI) by gender and for each independent variable. Finally, to analyze which demographic and socioeconomic factors are associated with SSB consumption, we first estimated the crude models, then adjusted them for the exposure variables that showed significance and obtained adjusted PR (aPR) with 95 % CI. Finally, we will modulate the adjusted prevalence ratio (aPR) for each exposure variable separately and jointly, while also taking into account the percentage change in the magnitude of association.

Specific objective 2:

Design of the study:

Cross-sectional study in which we will compare data collected from the Desk-cohort project over three academic courses (2019-2020, 2021-2022, and 2023-2024) to analyze trends over time.

Target population and sample selection:

The target population over three academic courses (2019-2020, 2021-2022, and 2023-2024)  was: 12- to 18-year-old students from various secondary education courses (2nd and 4th of compulsory secondary education (CSE); 2nd of post-compulsory secondary education (PCSE); and 2nd of Intermediate Level Training Cycles (ILTC) in Central Catalonia.

In the first wave, in the academic year 2019-2020 out of the 91 schools invited to participate, 65 (71.4%) agreed to participate, with 31% being private and 69% being public. Students who did not answer questions with less than 10% missing values were excluded, resulting in a removal of 12.2% of the total sample. A total of 7,319 participants were initially considered for the study. After excluding subjects with missing values, the final sample size consisted of 6,428 adolescents, 3,105  were boys and 3,323 were girls.

In the second wave, in the academic year 2019-2020, out of the 98 schools invited to participate, 85 (86.7%) agreed to participate. Students who did not answer questions with less than 10% missing values were excluded. The project included 9,265 participants (4,558 boys and 4,707 girls).

We plan to continue data collection in the 2023-24 academic year for the third wave of the study, with the aim of achieving a similar level of participation as in the second wave.

Variables and instruments:

Data collection is the same I mentioned in specific objective 1. The data collection for this study involved the use of a questionnaire to collect data on various health-related variables from students in 2nd ESO, 4th ESO, 2nd high school, and 2nd Intermediate Education Cycles. The questionnaire was designed based on other similar surveys, self-administered through tablets, and lasted about 40 minutes. The project was approved by the Research Ethics Committee of the Universitat de Vic-Universitat Central de Catalunya.

The dependent variable will be the consumption of SSB above the current recommendations in all waves, which was built from the answers to the question: How often do you drink soft drinks? There were seven possible responses: 1) More than once a day; 2) Once a day; 3) Between 4 and 6 times a week; 4) Between 2 and 3 times a week; 5) Once a week; 6) Between 1 and 3 times a month; 7) Never or less than once a month.

The independent variables will include adolescent student’s course (2nd and 4th ESO (CINE 2), 2nd Baccalaureate, and Middle-Grade Training Cycles (CINE 3)), gender (male/female), socioeconomic status (perceived SEP measured by the MacArthur Scale of Subjective Social Status) and temporary time of data collection, which will be collected over time within the same wave and between different waves of the Desk-cohort study.

Other exposure variables, were referred to lifestyle: tobacco consumption (daily consumption), alcohol consumption (2 or 3 times per week) and physical activity (it should consist at least in 1 h a day of vigorous or moderate exercise, in compliance with the WHO recommendations)

Analysis plan:

The study will estimate the prevalence of high school students in Central Catalonia who consume SSB above the current recommendations in the academic years 2019-2020, 2021-2022 and 2023-2024, and will analyze the evolution of consumption throughout the time Statistical analyses, such as descriptive statistics and regression models, will be used to investigate differences in age (student course), gender and socioeconomic status of adolescents within and between different waves of the study in relation to students’ SSB consumption above current recommendations.

Specific objective 3:

Design of the study:

Cross-sectional study with data from the wave 3 of the DESK-cohort project, which will be collected in the 2023-24 academic course and contextual data from the environment of the educational centers.

Target population and selection of the sample:

The target population is 12- to 18-year-old students from various secondary education courses (2nd and 4th of compulsory secondary education (CSE); 2nd of post-compulsory secondary education (PCSE); and 2nd of Intermediate Level Training Cycles (ILTC) in Central Catalonia during the academic year 2023-2024.

We don’t know yet the level of participation but we have the aim of achieving a similar level of participation as in the second wave.

Variables and instruments:

The dependent variable will be the consumption of SSB above the current recommendations of third wave, which was built from the answers to the question: How often do you drink soft drinks? There were seven possible responses: 1) More than once a day; 2) Once a day; 3) Between 4 and 6 times a week; 4) Between 2 and 3 times a week; 5) Once a week; 6) Between 1 and 3 times a month; 7) Never or less than once a month.

The main independent variable will be the availability of SSB within the environment of the educational centers surveyed.

As independent variables, we also considered socioeconomic status (measured by the MacArthur Scale), gender (male/female), the student’s course (2nd and 4th ESO (CINE 2), 2nd Baccalaureate, and Middle-Grade Training Cycles (CINE 3)) of participants of the third wave, tobacco consumption (daily consumption), alcohol consumption (2 or 3 times per week), and physical activity (it should consist of at least in 1 h a day of vigorous or moderate exercise, in compliance with the WHO recommendations).

Analysis plan:

This study will examine the association between SSB consumption and several independent variables, including SSB availability, socioeconomic status, gender, grade, tobacco and alcohol use, and physical activity. Descriptive analysis will be used to calculate the frequency distribution of SSB consumption, and the demographic characteristics of the sample will be described. Bivariate analysis will be performed using chi-square tests or Fisher’s exact tests to examine the relationship between SSB consumption and each independent variable. Finally, the results will be interpreted and presented, including a discussion of the significance of the results in relation to the research objectives and the existing literature.

Ethical considerations for all specific objectives:

Ethical considerations are crucial to ensure that participants are treated with respect and that their rights are protected. These are the ethical aspects that must be taken into account in the methodology:

Informed consent: Although the participants have already been informed about the purpose, procedures, risks and benefits of the research before agreeing to participate voluntarily it should be mentioned.

Confidentiality: The study must ensure the confidentiality of participant information. The identities of the participants are anonymous and the data collected must be coded to avoid possible personal identification. Data must be stored securely to prevent unauthorized access.

Data protection: Data collected from participants must be protected. Researchers must comply with the data protection laws of the country where the research is conducted. Any personal information collected must be kept secure and not shared with unauthorized persons.

Ethics approval: The study must be approved by an ethics committee before it can be carried out. Researchers must ensure that the study complies with the ethical guidelines established by the committee. Any changes in study design or procedures must be approved by the committee before implementation.

In summary, ethical aspects such as informed consent, confidentiality, data protection and ethical approval must be considered in the methodology to ensure that the study is conducted ethically and that the rights of the subjects are protected.

Means and resources

Special software or equipment

To conduct the different studies of the thesis proposal, we will need access to the databases of the different waves of the DESK-cohort project (wave 1: 2019-2020; wave 2: 2021-2022; wave 3: 2023-2024). Data will be obtained through the study coordinators or the responsible institution.

To analyze the results of the study and determine its effectiveness and statistical software to analyze the data, such as SPSS, STATA or R, which may require a license or subscription.

Costs associated with dissemination results

We will identify appropriate dissemination channels to share the study results, including scientific publications and presentations, media outlets, and public health organizations. Additionally, it is essential to consider the costs associated with publishing in a journal such as Nutrients, Journal of Nutrition, British Journal of Nutrition, etc.

Work plan

First-year

Preliminar task: Develop a detailed research plan outlining the research questions, objectives, methodology, resources and timeline.

Task 1: Develop research questions and objectives

Action 1: Conduct preliminary research to identify the current knowledge and gaps in the field.

Action 2: Consult with stakeholders or experts to gather input on potential research questions and objectives.

Task 2: Conduct a literature review to identify gaps in knowledge

Action 1: Search academic databases and relevant literature sources to gather articles and studies related to the research topic.

Action 2: Analyze and synthesize the literature to identify gaps in knowledge

Task 3: Broadly determine the appropriate research methodology and study design

Action 1: Consult with thesis supervisors about the most appropriate methodology and study design for the research project.

Task 4: Identify and allocate resources, including staff, funding and equipment

Task 5: Develop working hypotheses

Action 1: Analyze the conclusions collected and knowledge gaps identified during the literature review

Action 2: Formulate working hypotheses based on this analysis.

Task 6: Design a work plan

Action 1: Develop a detailed work plan that describes the tasks and schedule of the research project.

Task 7: Revise and refine the research plan as necessary during the first year

Action 1: Periodically review progress and make adjustments to the research plan as needed and incorporate feedback from team members, stakeholders, or advisors to refine the plan through delivery.

Deliverables for the first year and chronogram:

The final deliverable document was the research plan at the end of the first year. It has been developed in different stages:

The state of art of the research plan that summarizes the current knowledge, the gaps in the field and the contributions collected from the interested parties or experts on possible questions and research objectives: It has taken us approximately 6 months.

Analyzing findings and identifying knowledge gaps during the literature review has provided valuable insights to formulate working hypotheses and the specific objectives grounded in existing knowledge. It has taken us approximately 2 months.

The methodology set out in the research plan on the collection of information and the design of the study: It took us around two months.

A detailed work plan outlining the tasks and timeline of the research project, including milestones and deadlines: It has taken us around two months

Second-year

Specific Objective 1 (SO1): To estimate the consumption of SSB above in adolescents from 12 to 18 years in Central Catalonia in the academic course 2021-2022, and analyze which demographic and socioeconomic factors are related to this consumption.

Task 1: Conduct a literature review on worldwide SSB consumption among school-aged adolescents.

Action 1: Identify relevant articles, reports, and studies.

Action 2: Extract and analyze data on SSB consumption rates, factors affecting consumption, and health outcomes.

Task 2: Analyze data from the Desk-Cohort study on SSB consumption among school-aged adolescents in central Catalonia.

Action 1: Obtain wave data from the Desk-Cohort project.

Action 2: Clean and process data to ensure accuracy and consistency.

Action 3: Conduct descriptive and inferential analyses to identify patterns and trends in SSB consumption.

Task 3: Review school-age food guidelines from the Generalitat de Catalunya and the World Health Organization.

Action 1: Identify and compare recommendations for SSB consumption.

Action 2: Analyze the rationale and evidence behind the recommendations.

Task 4: Evaluate SSB consumption rates among school-aged adolescents in central Catalonia in relation to the school-age food guidelines recommendations.

Action 1: Compare Desk-Cohort study data on SSB consumption to school-age food guidelines recommendations.

Task 5: Prepare documents and presentations for disseminating results.

Action 1: Write the first draft of the article about it.

Action 2: Share the first draft with the coauthors for their review and contributions

Action 3: Present the article for submission to a peer-reviewed journal.

Action 4: Prepare one presentation for local and national conferences.

Deliverables for the second year and chronogram:

Short report for thesis supervisors on the results of the descriptive and inferential analysis of SSB consumption among school-aged adolescents in central Catalonia. It is estimated that it can be carried out in about 5 months.

Delivery and sharing of the first draft of the article to the co-authors for their review and input. Approximately it will take 5 months.

Submit the article for submission to a peer-reviewed journal. About 2 months I will be need to do this task.

Deliver a presentation on the article for local and national conferences. It will take almost a month.

Third-year

Specific Objective 2 (SO2): To estimate the prevalence of high-school students aged from 12 to 18 years of Central Catalonia that consume SSB above the current recommendations in the academic courses 2019-2020, 2021-2022, and 2023-2024, and analyze the changes in consumption over time.

Task 1: Data Analysis

Action 1: Clean and prepare the data for analysis.

Action 2: Conduct exploratory data analysis (EDA) to identify patterns and trends in the data.

Action 3: Estimate the prevalence of high-school students who consume SSB above the current recommendations in the academic courses 2019-2020, 2021-2022, and 2023-2024.

Action 4: Analyze changes in consumption over time using regression models.

Task 2: Dissemination of Results

Action 1: Write the first draft of the article about it.

Action 2: Share the first draft with the coauthors for their review and contributions

Action 3: Present the article for submission to a peer-reviewed journal.

Action 4: Prepare one presentation for local and national conferences.

Deliverables for the third year and chronogram:

Short report for thesis supervisors on prevalence and changes in SSB consumption among high-school students in Central Catalonia. It is estimated that it can be carried out in about 5 months.

Delivery and sharing of the first draft of the article to the co-authors for their review and input. Approximately it will take 5 months.

Submit the article for submission to a peer-reviewed journal. About 2 months I will be need to do this task.

Fourth-year

Specific Objective 3 (SO3): To analyze the association between the consumption of SSBs in high-school students aged from 12 to 18 years in Central Catalonia and the exposure to unhealthy food and beverage in their school environment.

Task 1: Data Analysis

Action 1: Prepare the data for analysis (cleaning, coding, and organizing).

Action 2: Conduct descriptive analysis of the data (e.g., frequencies, means, standard deviations).

Action 3: Conduct inferential analysis to explore the relationship between the consumption of SSBs and the exposure to unhealthy food and beverage in the school environment (e.g., chi-square test, t-test, regression analysis).

Task 2: Dissemination of Results

Action 1: Write the first draft of the article about it.

Action 2: Share the first draft with the coauthors for their review and contributions

Action 3: Present the article for submission to a peer-reviewed journal.

Action 4: Prepare one presentation for local and national conferences.

Deliverables for the fourth year and chronogram:

Short data analysis report, tables and graphs to illustrate the results to thesis supervisors. It could take around 5 months.

Delivery and sharing of the first draft of the article to the co-authors for their review and input. Approximately it will take 5 months.

Submit the article for submission to a peer-reviewed journal. About 2 months I will be need to do this task. It will take almost a month

Fifth year

Body of the Thesis and defense preparation

Task 1: Prepare the body of the thesis and the defense.

Action 1: Conduct an extensive literature review: Conduct an extensive review of the relevant literature to establish the theoretical framework and contextual background of the research.

Action 2: Write the methodology. Define the research design, data collection methods and data analysis techniques used in the study.

Action 3: Write the data collection and analysis section of all the research that addressed the research objectives and confirm or disprove the formulated hypotheses.

Action 4: Write the results and discussion section to present the study’s findings clearly and coherently, discussing their implications and relevance.

Action 5: Summarize the main findings, draw conclusions from the results and provide recommendations for future research.

Action 6: Preparing the thesis defense: prepare the thesis defense by reviewing the entire thesis, anticipating possible questions and rehearsing the research presentation.

Deliverables for the fifth year and chronogram:

Extensive review of the relevant literature to establish the theoretical framework and contextual background of the research. It could take around 2 months.

Drafts of the thesis document that will be delivered periodically in the final year to the co-authors for their review and input. Approximately it will take 8 months.

Comprehensive thesis document ready for submission and a presentation to defend the research. It will take almost a month or two.