This study used an experimental design with purposive sampling to gather data from Malay adolescents aged 14 to 16 years who attended selected secondary schools in Kuala Lumpur, Malaysia. Without a control group, the chosen single-group experimental approach ensured uniform access to the educational material among all participants, aligning with ethical and practical considerations in academic research. Practical constraints within the school settings, such as challenges in recruiting a comparable control group and ensuring their nonexposure to the e-book, further supported the selection of this design. Despite inherent limitations in terms of internal validity, particularly threats related to the absence of a control group, this study represents an initial exploration of e-books as educational tools for adolescents.

Initially, invitations were extended to 14 schools, with 6 granting permission for participation following the dissemination of relevant information to homeroom teachers. Eligible participants were required to have access to electronic devices, such as mobile phones, tablets, or computers, with internet connectivity. Adolescents with health conditions, including visual or hearing impairments, autism spectrum disorder, attention-deficit/hyperactivity disorder, Down syndrome, cerebral palsy, dyslexia, aphasia, or physical disabilities, were excluded from this study.

Ethical approval was obtained from the Universiti Kebangsaan Malaysia’s research ethics committee (reference code: UKM PPI/111/8/JEP-2022‐139). The data collected in this study were anonymized by using a study-specific identification number. Further, participants were given a notebook worth RM 5 (US $1.12) as a token of appreciation.

The research information sheet and an informed consent and screening form were disseminated through a web-based platform (WhatsApp [Meta Platforms] messages with a document link) by homeroom teachers. Interested participants who met the eligibility criteria and obtained parental or guardian consent were contacted and provided with a link to access the pretest questionnaire via Google Forms. This questionnaire gathered sociodemographic information, assessed knowledge about osteoporosis, and collected data on physical activity levels.

After completing the pretest questionnaire, a video call session via Google Meet was scheduled to assess habitual dietary calcium intake. Participants were subsequently given access to an e-book on bone health and instructed to read it within 2 weeks. At the end of this period, participants completed a posttest questionnaire, which was almost identical to the pretest questionnaire but excluded sociodemographic information. Additionally, the posttest questionnaire included a section to assess participants’ acceptance of the e-book. A second video call session via Google Meet was conducted to reassess participants’ dietary calcium intake. The entire data collection process was conducted via the internet to minimize interference with school schedules.

Data were analyzed by using IBM SPSS Statistics software (version 26.0; IBM Corp). The normality of continuous data was assessed by using the Shapiro-Wilk test. Descriptive statistics were reported as means and SDs for normally distributed data or medians and IQRs for nonnormally distributed data. Categorical variables were summarized as frequencies and percentages. The Wilcoxon signed rank test was used to compare pre- and postintervention scores of knowledge, physical activity, and calcium intake, due to the nonnormal distribution of the data. For categorical variables, associations and comparisons were assessed by using the chi-square test or McNemar test. A P value of <.05 was considered statistically significant.

A total of 72 participants (age: mean 15, SD 0.74 y) were enrolled in this study, and no dropouts were recorded (Table 1). The majority of the participants were female (n=51, 71%). The household income distribution was nearly evenly split among the low-income (n=23, 32%), middle-income (n=23, 32%), and high-income (n=26, 36%) categories. Most participants (n=51, 71%) were within the normal weight range, with a mean BMI of 20.9 (SD 4.5) kg/m². Only 1 participant reported prior education on bone health.

The educational intervention significantly improved participants’ knowledge of osteoporosis; the median knowledge score increased from 40.6% (IQR 31.3%-46.9%) in the pretest to 71.9% (IQR 53.9%-81.3%) in the posttest (P<.001; Table 2). Before the intervention, the majority of the participants demonstrated low levels of knowledge (69/72, 96%). There was a notable improvement after the intervention, with 38% (27/72) achieving moderate knowledge and 32% (23/72) reaching a high level of knowledge.

Table 3 presents the percentages of correct and incorrect responses (“False” or “Do not know”) before and after exposure to the educational materials. Significant improvements were observed across all knowledge domains. Notably, 36% (26/72) of participants remained unaware that aging increases the risk of osteoporosis. Similarly, a small proportion of participants did not recognize the benefits of aerobic dancing for bone health (8/72, 11%), the fact that cheese is a good source of calcium (8/72, 11%), and that adolescence is a critical period for building strong bones (2/72, 3%).

No significant differences were observed in dietary calcium intake (P=.31) and physical activity levels (P=.09) among adolescents following the intervention. Most participants exhibited inadequate calcium intake before (61/62, 98%) and after (61/62, 98%) the intervention. Similarly, a high proportion of participants maintained low levels of physical activity before (51/62, 82%) and after (48/62, 77%) the education intervention (Table 4).

Table 5 shows participants’ feedback on the e-book. Overall, 97% (70/72) reported understanding the e-book content, with 71% (63/89) of responses (for the “Reasons for good understanding” question, participants could choose multiple responses) indicating that simple and easy-to-understand language facilitated comprehension. Furthermore, 93% (67/72) of participants emphasized the importance of graphics in the e-book, and nearly all participants (71/72, 99%) found the visuals attractive. Additionally, 78% (56/72) agreed that the color combination enhanced their reading experience, while most adolescents considered the layout of the pictures (60/72, 83%) and the font size (66/72, 92%) to be appropriate.

This study demonstrates the effectiveness of an e-book–based educational intervention in enhancing adolescents’ knowledge of bone health and osteoporosis. Our findings align with a meta-analysis of 18 studies, which reported significant differences in osteoporosis knowledge among adolescents between educational intervention groups and control groups [30]. Similar improvements have been observed across various populations, including adolescents [45], health care professionals [46], university students and academicians [47,48], and patients with osteoporosis [49]. Given the critical importance of maximizing peak bone mass during adolescence, implementing educational programs is highly justified [31].

Educational initiatives using diverse approaches and methods have consistently proven effective in increasing knowledge [45]. Web-based learning platforms offer flexible and accessible avenues for knowledge acquisition. Furthermore, leveraging technological advancements, such as those related to text, audio, and visuals, enhances information dissemination. This facilitates the development of interactive learning tools, such as images and videos, which effectively convey critical aspects of osteoporosis, such as nutrition and weight-bearing exercises [50].

Despite significant gains in knowledge, this study did not observe notable improvements in dietary calcium intake and physical activity among adolescents after the intervention. Most adolescents (61/62, 98%) exhibited inadequate dietary calcium intake, with the median daily intakes before (median 576, IQR 473-688 mg/d) and after (median 586, IQR 491-755 mg/d) this study being below the recommended 1300 mg/d [16]. This trend aligns with findings from a previous study of Malaysian adolescents, in which all participants (N=794) had inadequate calcium intakes (calcium intake: mean 377.4, 95% CI 365.1-389.7 mg/d) [22]. Similar inadequate calcium intakes among adolescents have been reported globally, including in Morocco (calcium intake: mean 522, SD 297 mg/d) [51], Brazil (calcium intake: mean 618.2, 95% CI 570.8-665.5 mg/d) [52], and the United States (calcium intake: mean 962, SD 478 mg/d) [53], indicating a widespread issue of low dietary calcium intake among adolescents. Adolescents appear to consume limited amounts of calcium-rich foods, particularly dairy products [51].

This study also highlighted low physical activity levels among participants, with median scores of 2.2 (IQR 1.9-2.6) during the pretest and 2.3 (IQR 1.9-2.9) during the posttest. This finding is consistent with a previous study of 13-year-old adolescents (n=289) in Malaysia, where low physical activity levels were reported (mean 2.01, SD 0.03) [21]. Again, our findings align with global trends, showing that many adolescents do not meet recommended physical activity levels. For instance, the WHO reported that globally, 81% of adolescents aged 11 to 17 years are insufficiently physically active [54]. Similar trends were noted in Portugal [55], Sweden [56], China [57], and Korea [58], of which all indicated low physical activity levels among adolescents. For instance, Marques et al [55] reported that in a sample of 520,533 participants, less than 20% of adolescents in Portugal participated in physical activity every day, and nearly 20% never engaged in any form of physical activity. Sedentary behaviors and insufficient physical activity negatively impact bone health and overall well-being.

The gap between increased knowledge and unchanged health behaviors suggests that knowledge alone may not suffice to promote positive practices. Addressing both knowledge and bone health practices simultaneously is essential. This underscores the need for a comprehensive approach that integrates knowledge acquisition and behavior change techniques to foster optimal adolescent bone health practices. Our findings contrast with previous studies that demonstrated favorable impacts of educational interventions on behaviors such as calcium intake and physical activity among adolescents [59-61]. These disparities could be due to variations in the educational methodologies, particularly in facilitating behavior changes [59]. Direct educational approaches, such as interactive sessions that promote engagement and motivation, have shown promising results in improving adolescents’ nutritional practices and physical activity levels [49,60,62].

It is worth noting that our intervention lasted for only 2 weeks, whereas previous studies implemented interventions over 2 to 3 months [60-62]. Behavior changes often require an extended period to be effectively integrated into daily routines [63]. The transtheoretical model of behavioral change suggests that behavior modification is a dynamic and individualized process involving various stages, including precontemplation, contemplation, preparation, action, and maintenance [64]. Therefore, extending the intervention period is essential to fully observe and understand the intervention’s effects and assess its sustainability.

Nevertheless, a longer intervention alone does not guarantee sustainable behavior change. Incorporating behavior change theories and techniques, such as goal setting, self-monitoring, and feedback, may enhance the intervention’s effectiveness. These techniques could facilitate the translation of knowledge into sustained behavior changes by actively engaging adolescents in their lifestyle practices. Additionally, using interactive elements, such as videos, quizzes, and simulations within e-books, can enhance the learning experience and support effective behavior change [65]. To ensure the long-term sustainability of the intervention, future studies should include systematic follow-up assessments to measure the retention of bone health–related knowledge and behaviors. Identifying barriers and facilitators to the ongoing use of the e-book, such as user engagement and perceived relevance, is also essential.

The e-book used in this study received positive feedback from adolescents, as they found it understandable, visually attractive, and well designed in terms of graphics and text size. Effective e-books should incorporate structured content and multimedia elements, such as sounds, graphics, images, text, and animations, to create an engaging and interactive learning experience [32]. e-Books can enhance adolescents’ understanding by using visual elements, including animated images, to convey the information more engagingly [66]. Incorporating interactive multimedia elements in e-books makes learning exciting, meaningful, and inspiring for adolescents [67]. Special animations and effects, such as graphics and sounds, effectively capture adolescents’ attention in educational settings.

This study is the first to assess Malay adolescents’ knowledge and practices related to bone health following an educational intervention in Malaysia. The findings suggest that the e-book is effective for health promotion among adolescents. These results provide valuable insights for planning strategies to promote bone health among adolescents and the wider community, such as through the use of e-books.

Study limitations include the absence of a control group and uneven proportions of male and female respondents, which could have introduced bias. Additionally, the osteoporosis knowledge questionnaire and dietary calcium intake assessment evaluation tools have yet to be validated in the studied population. Furthermore, this study focused solely on calcium intake and physical activity, excluding other essential factors, such as vitamin D intake. The short intervention period also limited the ability to evaluate long-term behavior changes. Future studies should extend the intervention duration and include a broader range of bone health practices to provide a more comprehensive assessment.

Future research should focus on enhancing the e-book’s content by incorporating more practical elements, such as easy-to-prepare recipes for calcium-rich foods and information on simple bone-health exercises. Integrating diversified and interactive educational content, including videos, quizzes, and simulations, can make learning more engaging and impactful. Such content can aim to engage adolescents and effectively promote the practical application of knowledge. To better foster sustained behavior changes, future studies should also consider extending the duration of the intervention period. Further, translating the e-book into other languages would increase its accessibility and cater to Malaysia’s diverse population. Moreover, conducting similar studies among non-Malay adolescents would offer a broader understanding of bone health practices across different ethnic groups in Malaysia.

The developed e-book on bone health effectively increased knowledge related to bone health and was well received by Malay adolescents within our sample. However, the intervention did not significantly influence bone health practices, including dietary calcium intake (P=.31) and physical activity levels (P=.09). Additional strategies that integrate knowledge enhancement with practical demonstrations, interactive activities, and targeted approaches are necessary to promote the adoption of healthy behaviors for optimal bone health.