Childhood overweight and obesity have emerged as public health crises, reaching a global dimension [1]. Overweight and obesity prevalence estimates from the fifth round of Childhood Obesity Surveillance Initiative (COSI) data collection (2018-2020), conducted in 33 countries of the World Health Organization (WHO) European Region, indicate that 29% of children aged 7 to 9 years are living with overweight, including 12% with obesity, with Italy ranking fourth highest [2].

Primary factors contributing to obesity in Europe—unhealthy dietary habits, lack of physical activity, high screen time, and poor sleep habits—stand as prominent drivers of preventable fatalities, chronic illnesses, and economic health burdens among young people. These modifiable determinants have been particularly challenged during the COVID-19 pandemic, across all population age groups, including children. The lockdown significantly impacted children’s lifestyle habits, contributing to increased sedentary behavior, extended screen time, and higher consumption of calorie-dense and sugary foods [3].

Total screen time, time spent on television, and time spent on the computer are positively correlated with overweight/obesity among children [4]. The pandemic has heightened the use of technology platforms, on the one hand, to facilitate communication and, on the other hand, to facilitate virtual education. Indeed, it has been reported that screen time has increased by about 5 hours per day compared to the pre–COVID-19 period [3]. However, this has exacerbated sedentary habits and increased snack consumption, resulting in weight gain [5]. Prolonged screen time can also affect the quality and quantity of sleep hours [6]. Inadequate sleep negatively influences several aspects of children’s and adolescents' lives, including physical and mental health and school performance [7]. Inadequate sleep is also correlated with increased cardiometabolic risk, leading to the onset of impaired fasting blood glucose, dyslipidemia, and increased blood pressure [8]. Along with excessive screen time, inadequate sleep is also associated with unhealthy eating behaviors. This could lead to an increased risk of obesity and overweight as evidenced by recent meta-analyses [9,10]

In such a sensitive and complex scenario, where many factors play a central role in maintaining good health conditions, more evidence-based policies, economic investments, and integrated programs are required [11,12]. In the past decades, several childhood abatement interventions have been carried out to address this issue, but increasing regional and global prevalence trends show that those have had little success [2,13,14]. Scientific evidence described how the “eat less, move more” attitude is too simplistic, and no single intervention can be successful in halting the advancement of the obesity epidemic. Therefore, modern policy actions have been prompted into executing integrated programs, which take into consideration: (1) multicomponent approaches including nutrition, physical activity, sleep hygiene, and so on; (2) multilevel efforts, including individual children, families, and school; and (3) multi-setting interventions, such as primary care clinics, homes, and community centers to prevent, contain, and manage childhood overweight and obesity [2,15,16].

Adherence to the Mediterranean diet (MD) and lifestyle represents a further piece of the puzzle as the primary prevention strategy for obesity recognized by many relevant scientific societies [17]. However, MD adoption has decreased in the past decades in most WHO member states, including countries in the Mediterranean basin and among younger individuals belonging to lower socioeconomic classes [18-20]. According to estimates of the most recent COSI data collected (2018-2020), less than half (43%) of the children in the WHO European Region consumed fresh fruit daily, and even less (34%) ate vegetables daily [2]. According to these data, their level of physical activity remains poor as well. Overall, 40% of children did not spend any time during the week doing sports, while 43% of children aged 6 to 9 years had at least 2 hours a day of screen time, with the prevalence reaching 76% on the weekends [2].

Italy is no exception. The transition toward Western dietary patterns, based on ultraprocessed foods and a sedentary lifestyle, is the consequence of numerous sociocultural and economic factors, such as an increased cost of living, changes in gender roles in society, urbanization, and globalization [21]. In particular, children of migrant backgrounds often shift away from traditional eating habits, increasing their consumption of processed foods, likely due to economic barriers [20,21]. As of January 1, 2020, Italy had 1.3 million children of migrant background aged 0 to 17 years, so it is clear that instilling nutritional education and promoting healthy lifestyle habits within this population group is crucial for reducing childhood obesity rates in the coming years [22].

Since establishing healthy dietary habits at an early age may prevent the onset of chronic diseases later in adulthood, schools have been recognized as powerful settings to provide nutritional and healthy lifestyle education and execute targeted interventions [15,23].

Archero et al [24] conducted a 2-month cross-sectional study in Novara, including 3 primary and 2 secondary schools, to assess the association between MD and weight status. The authors found a higher prevalence of overweight and obesity and a lower adherence to MD in children attending primary school compared to other schools. Another cross-sectional study was conducted by Paduano et al [25] to investigate the physical/sedentary activities of first-year primary school children in Modena and their association with overweight/obesity and dietary habits. The authors found that 3 out of 4 children spent less than 7 hours a week engaged in physical activities, while 63.9% dedicated 2 or more hours a day to sedentary activities. Recently, the Italian National Institute of Health, in collaboration with the Ministry of Health, implemented a project, called “Maestra Natura” [26] aimed at promoting healthy lifestyles and improving knowledge about food and nutrition in elementary school children. The results showed a significant improvement in knowledge (P <.001) in the intervention group compared to the control group.

Despite several actions carried out to counteract childhood obesity in Italy [24-26], the rising incidence of obesity demonstrates that the measures adopted have been ineffective at achieving their short- and long-term goals [27]. In this context, the LIVELY (Multidimensional School-Based and Family-Involved Interventions to Promote a Healthy and Sustainable Lifestyle) study aims to address the prevalence of overweight and obesity among primary school children and its determinants, as well as to set up and evaluate the feasibility of a multidimensional school-based educational intervention for preventing childhood obesity.

LIVELY is a single-arm pre-post study (without a control group). The study is being conducted by a multidisciplinary team consisting of researchers from the Istituto di Ricerche Farmacologiche Mario Negri IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico) of Milan and the Laboratory of Dietetics and Clinical Nutrition from the University of Pavia.

LIVELY is being carried out at Istituto Comprensivo ”Luigi Cadorna,“ a public primary school with a strong multiethnic component in northwest Milan, Italy. The study will run from October 2023 until October 2024. Figure 1 shows the study flowchart and timeline.

The target population for the study was children from 5 to 12 years of age, of both sexes and any ethnicity, and their families. Only children whose parents or legal guardians approved and signed the informed consent were included.

The multidisciplinary team organized an initial meeting at the participating school to introduce the project to the dean and teachers. Teacher representatives took charge of presenting the project to the families of the various classes. Interested families were provided with a study information sheet, which was translated into different languages (Arabic and English) to accommodate the school’s diverse, primarily Arabian, population. Teachers in participating classes distributed informed consent and privacy forms in the families’ native languages. Signed documents were required from all families before their children could participate.

The LIVELY study was approved by the Fondazione IRCCS Istituto Neurologico Carlo Besta Ethics Committee (protocol 11) in January 2023. It follows the principles of the Declaration of Helsinki and complies with all relevant privacy and confidentiality regulations concerning the participants' data. Written informed consent was obtained from parents or legal guardians before data collection. Each participant was assigned a unique code to link their data securely while protecting their identity.

Details of the data collected from the children and their families throughout the study period are summarized in Table 1.

The evaluation of educational interventions will aim to analyze and interpret relevant aspects of the multidimensional intervention. It will involve both the school team (teachers) and the recipients (children and families) participating in the LIVELY project and will be conducted at the end of the school year (T1).

The feasibility of the multidimensional educational intervention at school will be assessed in terms of satisfaction, learning, and organization. Three main areas of evaluation of educational interventions will be distinguished, namely, satisfaction (by children, families, and teachers), learning (by children), and organizational impact in the work context (by teachers).

The children's and their families' satisfaction will be assessed through an ad hoc questionnaire investigating the level of appreciation regarding the proposed activities. The children's knowledge of the topics covered in the lessons (healthy and sustainable nutrition and lifestyle) will be collected through age-appropriate questionnaires (true/false items, multiple-choice items, insertion) or short compositions, depending on their age group. This assessment will help us determine whether the concepts explained in the lessons have been learned and whether the educational model used is appropriate for the target population. The overall satisfaction and organizational impact of the interventions will be evaluated by teachers through an ad hoc structured questionnaire, which will explore the following issues: (1) usefulness (definition and consistency/congruence of the multidimensional interventions with the project objectives, (2) usefulness of the interventions and materials prepared), (3) didactics (competence and appropriateness of the teaching techniques of the study teams addressed to the subjects, support received by the study teams during the implementation of the activities), (4) organization, and (5) services (timing, facilities and appropriateness of the schools' premises). In addition, teachers will be asked to refer to the reproducibility of the intervention in other classrooms or schools. All items in the questionnaire will be rated on a Likert-type scale.

This type of study did not require a sample size calculation, but we expected to enroll about 300 to 350 children aged between 6 and 12 years from 15 to 20 classes (in primary school and in the first class of secondary school) based on the availability/willingness of teachers to participate and the resources.

This would allow us to estimate the prevalence of overweight and obesity between 23% and 24%, with a 20% relative precision and within a 95% CI. These data are in line with those observed in the Okkio alla Salute 2019 survey in the Lombardy region [41].

Descriptive analysis will be performed to summarize the baseline characteristics of the involved children according to normal weight, overweight, and obesity classifications. Descriptive data were expressed as counts (percentages) for categorical data and as means (SD) for continuous variables. The means for continuous variables were compared using independent group t tests when the data were normally distributed; othewise, the Mann-Whitney test was applied. Categorical variables were compared using the chi-square test. Main determinants of overweight/obesity among children will be investigated according to clinical conditions, dietary patterns, physical activity habits, and environmental and behavioral (family) conditions collected at the baseline using logistic/multinomial regression models.

Specifically, according to the questionnaire results and the information collected in the CRF, children will be identified as “fully adherent,” “partially adherent,” or “poorly adherent” to the WHO recommendations regarding eating and lifestyle habits [42].

The obesogenic environment will be investigated by summarizing all information collected with an appropriate index by assigning a score ranging from 0 (least obesogenic) to 100 (most obesogenic). Each item will be assigned a score from 0 to 1: variables that were considered positive aspects of the environment (grocery, stores/superstores, exercise opportunities) will be reverse scored so that a lower score for these variables indicates a healthier environment. Variables that are considered negative aspects (fast food restaurants, food budgets at home, using a car to go to school) will be scored as is, so a higher score indicates an unhealthy environment. The final index will be calculated by summing up the score for the single items and then normalized to lie between 0 and 100.

Indices for each dimension and an aggregate index will also be calculated to assess the level of satisfaction with the training intervention, learning and overall knowledge of the topic, and the intervention’s organization and reproducibility. Multivariate statistical analysis will be used to investigate general and specific quality dimensions and factors, and it will be correlated with the other aforementioned measures. Changes in dietary and lifestyle habits in the children, behavioral attitudes of their families, and the children's anthropometric measurements will be assessed at 6 (T1) and 12 months (T2) starting from baseline. All results will be stratified by sex and age groups.

Recruitment lasted throughout October 2023. Out of the 275 children from the 14 classes participating in the project, 227 whose parents approved and signed the informed consent were included in the study.

The mean age was 8.9 (SD 1.2) years, and 48% (n=110) were males. Children from the 14 classes were distributed as follows: 5.3% (n=12 children) from the second year (1 class), 33.9% (n=77 children) from the third year (5 classes), 15.9% (n=36 children) from the fourth year (2 classes), and 44.9% (n=102 children) from the fifth year (6 classes). No first-graders took part in the project. Data related to demographic data, including age, ethnicity, weight, height, BMI z score, and WHtR are shown for the total population and by sex in Table 3.

The percentage of normal weight, overweight, and obesity (defined by BMI z score) and central obesity (according to the WHtR cut-off) is reported in Table 4. Among the overall sample, 18.1% (n=41; 95% CI 13.7%-23.7%) were overweight, while 5.3% (n=12; 95% CI 3%-9%) were obese. Male students had a higher prevalence of obesity than female students (9.1% vs 1.7%, P=.03 respectively). Conversely, the overall prevalence of central obesity was similar between male and female students, respectively (31% vs 37%, P=.329).

The second data collection was completed in June 2024 (T1), and the last data collection will be completed by the end of October 2024 (T2). Data analysis and a presentation of the complete results will be available after the end of 2024.

The rising prevalence of obesity worldwide represents a growing burden of noncommunicable diseases (NCDs) and a significant public health issue due to increasing public service health costs [13,18,43]. To prevent the early onset of NCDs in younger populations, additional policies, treatments, and financial investments must be made to contrast the growing pandemic of childhood obesity [44-46]. Based on scientific research [15], preventing childhood obesity requires a multifaceted approach including multiple areas of intervention. Therefore, it is essential to develop and carry out integrated programs that could cover a variety of topics (nutrition, physical activity, sleep hygiene, etc) at various levels (individual, family, school, and institutional) [47].

The LIVELY study enrolled 227 school-age children attending an elementary school in a multiethnic neighborhood in north Milan, Italy. Classes from the second to the fifth grade were included. No first-grade class joined the project because the availability of children to follow the lesson could not be optimal. This was because, during the first year of elementary school, children were just beginning to learn how to read and write, leading primary school teachers to abstain from participating in the project.

In line with previous studies [24-26], our preliminary results showed a high prevalence of overweight/obesity among the enrolled children, at 24% (n=26) for the male students and 23% (n=27) for the female students, with a higher prevalence of obesity among males (P=.007). Interestingly, the prevalence of central obesity was similar between the 2 sexes (P=.329).

A child's diet and physical activity can be significantly influenced by their surroundings, particularly family and school [48]. To date, many programs have been developed to prevent obesity in children, but the overall impact of these is questionable and does not include long-term follow-up measurements [24-26]. Thus, the LIVELY study has significant strengths. First, interventions involving different actors (children, families, teachers) and multidisciplinary professional expertise will be implemented, allowing us to address the different determinants of childhood obesity. Second, frontal lectures and games relating to the subject matter will be adapted to all age groups, dividing the children into 2 groups—first and second graders in one group, and third to fifth graders in the other. The strong multicultural component of the sample will be considered by involving them in stimulating and bonding activities. Third, an interactive digital lab will be developed to maximize learning outcomes by taking advantage of the children’s digital skills. Fourth, attention will be given to the opinions of all participants (children, parents, and teachers) to assess the feasibility and reproducibility of the project.

There are several possible obstacles to this research in real-world contexts; some that we can foresee now and others that will be managed as they arise. We have already encountered 2 main challenges. The first challenge comprised the teachers’ active involvement and participation. Some teachers expressed that they found it difficult to include new lectures in the already tight teaching schedule as all classes are conducted during regular school hours and included within the Civic Education class period. However, it was possible to overcome this obstacle by involving the school principal and explaining to teachers the importance and impact of the project since the topics covered are not part of the regular school curriculum and will cover current and important issues such as sustainability and planetary health. Moreover, this approach aligns with the Sustainable Development Goals outlined in the 2030 Agenda for Sustainable Development, adopted by all United Nations Member States, and integrated into Civic Education curricula by the Italian Ministry of Education in 2020. The second challenge concerned the large multicultural component of the sample, as language barriers can play a critical role. To minimize this obstacle, most of the tools concerning completion by families (informed consent, releases, and questionnaires) were translated into 3 different languages (Italian, English, and Arabic).

We anticipate challenges with family compliance in completing the self-administered questionnaires. To address this, we plan to make phone calls to the families to fill in the questionnaires or enter the missing data with the support of trained staff. Another challenge may arise from the difficulty in collecting data at 12 months from children transitioning from 5th grade to 6th grade, as they will be changing school locations. We plan to mitigate this issue by maintaining contact with teachers and parents. In addition, through satisfaction questionnaires, the project’s various stakeholders will be given a voice to highlight the strengths and address any critical issues through different perspectives.

The LIVELY study will provide key insights into the prevalence of overweight and obesity in a primary school setting and identify their main determinants. It is expected to benefit the study population by conveying, through a multidisciplinary, multiprofessional, and reproducible approach, the basics of a healthy and sustainable lifestyle. The ultimate goal is to reduce—and altogether prevent—childhood obesity.