The worldwide prevalence of obesity among children is 13.9% [1], and adolescents present the highest prevalence (34.5%) amongst different children age groups [2]. Notably, trends reveal that the prevalence of overweight and obese adolescents is increasing [3,4]. Adolescents who are overweight and obese show an increased risk of being obese in adulthood [5], and they are at risk of developing type 2 diabetes mellitus, cardiometabolic risks, cardiovascular mortality [[6], [7], [8]], and psychosocial problems [9]. Given the adverse health outcomes and high prevalence rate, effective interventions are needed to target overweight and obese adolescents.
Self-monitoring is a behaviour change technique that is essential to the success of weight management [10,11]. However, the traditional practice of self-monitoring using paper diaries is difficult due to the complexity of recording [12]. Given that almost 90% of adolescents are daily internet users [13,14], the internet may offer a new opportunity to engage in self-monitoring [15]. Therefore, internet-based self-monitoring interventions may potentially overcome previous challenges and allow considerable compliance [12,16] by offering high usability, accessibility, cost-effectiveness and convenience [17,18] with interactive multimedia, graphical features, tracking systems, sensor-based devices, individualised feedback and asynchronous and synchronous interactions [[19], [20], [21]].
Self-monitoring intervention was recommended as an essential strategy for adult weight management in four systematic reviews [10,11,22,23]. A growing number of systematic reviews have supported the use of internet-based interventions in achieving weight loss in adults [[24], [25], [26]], but little is known whether it could be generalised to adolescents who are overweight and obese is unclear.
Three previous systematic reviews [[27], [28], [29]] reported internet-based weight management interventions to be effective in reducing BMI outcomes for overweight or obese adolescents. The components identified to contribute to weight loss were the use of feedback and reminders [28], parental involvement [[27], [28], [29]], and behaviour changing techniques [29]. However, the effectiveness of internet-based weight management could not be isolated due to the multiple components involved and evidence was limited to short-term outcomes with only one study with outcomes beyond one year [[27], [28], [29]]. These reviews were limited to a few selected trials (n = 4) [27], some double counting the same trial [28,29], included trials with heterogeneous age groups with a mixture of normal weight, overweight and obese participants [27] and various study designs [27]; in addition, none of these reviews used a meta-analytic approach. Meta-analysis obtains the strongest and highest quality of evidence [30]. Thus, further rigorous review is warranted to fill the gaps.
This review aims to (1) systematically locate, appraise and synthesise evidence on the effectiveness of internet-based self-monitoring interventions in overweight and obese adolescents based on BMI or BMI z-score and (2) identify essential components, formats and approaches in designing interventions according to theory-based intervention, frequency, counselling provision, goal setting, different self-monitoring components, professional support, parental involvement and intervention duration. The results from this review may be useful to provide future recommendations in designing effective interventions.
This systematic review and meta-analysis is reported in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) [31], referred to in the PRISMA Checklist in Table S1. This review is also registered in the PROSPERO database (CRD42016050089).
The systematic search process is illustrated in Fig. 1. A total of 6841 records were generated from the seven databases. We removed 2091 duplicates using ENDNOTE software. Two reviewers independently screened and excluded 2521 records by assessing the titles and 2161 records by evaluating the abstract. We downloaded 68 full-text articles with the eligibility criteria. Fifty-eight articles were excluded due to the reasons given in Fig. 1. Table S5 provides a list of studies with the reasons for
To the best of our knowledge, this review is the first meta-analysis to quantitatively synthesise the evidence of internet-based self-monitoring intervention for overweight and obese adolescents, and the results support the use of internet-based self-monitoring for reducing BMI and BMI z-score. Subgroup analyses suggested that daily multicomponent self-monitoring, goal setting and professional face-to-face counselling with parental involvement were effective in reducing BMI. For the secondary
The internet provides interactive ways to gain knowledge, exchange information and self-monitor through a diverse range of advanced functionalities. Internet-based self-monitoring is a possible approach for overweight and obese adolescents to reduce their BMI and BMI z-scores. Daily multicomponent self-monitoring and goal setting should be incorporated into the intervention with considerations for face-to-face professional counselling and parental involvement. The overall low-quality evidence
The authors’ primary responsibilities were as follows: Y.L., T.H, C.L. and S.N.W developed the review question and design the review. S.N.W. supported searching strategies and Y.L., T.H. and C.L. screened, selected and reviewed the data. Y.L. and T.H. synthesized the data and interpreted the results. Y.L. wrote the manuscript and all authors contributed comments for finalize manuscript. All authors approved the final submitted version.
No conflict of interest was declared. Summary points What are already known? Adolescents who are overweight and obese show an increased risk of being obese in adulthood. Self-monitoring is a behaviour change technique that is essential to the success of weight management. Internet-based self-monitoring interventions may potentially overcome previous challenges and allow considerable compliance. What this study adds? Meta-analysis revealed that the use of internet-based self-monitoring had small
This study is support by the Humanities & Social Sciences Seed Fund Grant (HSS Seed Funding-1/2016, WBS no: R-545-000-076-646) from National University of Singapore, Singapore. We would like to acknowledge authors for sharing their additional study data, which was a great help for us to conduct the meta-analysis.
Importantly, the Keeners were the only ones who saw significant improvements in the targeted mediators (i.e., increase in knowledge, self-efficacy, and intrinsic motivation), highlighting that the app likely worked for a subgroup of users (i.e., the Keeners) for some the health behaviors targeted by the app. Previous studies have found that apps can be effective at changing health behaviors (Ho et al., 2018) but there is a limited number of studies among teens. In Aim2Be, the aims, tasks, and knowledge center features were hypothesized to support self-regulatory processes in teens (Mâsse et al., 2020); however, as the impact on teen’s health behaviors was limited it might be important to examine whether these components are working as hypothesized.
