Eating disorders (EDs) are psychiatric disorders defined as abnormal eating habits that negatively affect a person’s physical or mental health and usually begin in late childhood or early adulthood. These are associated with significant medical, psychiatric, and psychosocial consequences.

The global burden of EDs was estimated at 6.6 million people by 2019 [1]. In Spain, the estimated prevalence was 13% in both sexes [2]. However, the COVID-19 pandemic had a negative impact on EDs, increasing the incidence among young people and the demand for care in most countries [3,4].

The most common EDs include anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and eating disorder not otherwise specified (EDNOS). AN is characterized by an intense fear of gaining weight, persistent behaviors that interfere with weight gain, and a distorted perception of one’s own body image. It often results in dangerously low body weight and can lead to severe medical complications, such as bradycardia, osteoporosis, amenorrhea, and electrolyte imbalances. BN involves recurrent episodes of binge eating—consuming unusually large amounts of food within a discrete period—followed by inappropriate compensatory behaviors, such as self-induced vomiting, excessive exercise, fasting, or misuse of laxatives or diuretics. Unlike AN, individuals with BN typically maintain their body weight within or above the normal range, which can delay recognition and diagnosis. BED is defined as repeated episodes of uncontrollable overeating without the regular use of compensatory behaviors, often accompanied by feelings of guilt, shame, and emotional distress. BED is the most prevalent ED and is frequently associated with overweight and obesity. EDNOS, now referred to in Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition as other specified feeding or eating disorder, encompasses clinically significant eating disturbances that do not meet the full criteria for AN, BN, or BED. Examples include atypical AN (significant weight loss despite normal weight), purging disorder, and night eating syndrome. EDNOS represents a substantial portion of ED diagnoses, especially in clinical settings, and is associated with comparable levels of psychological distress and functional impairment [5,6]. The onset of EDs generally occurs between the ages of 10 and 20 years, although BED and EDNOS may appear in slightly older age groups [6].

EDs are associated with numerous physical problems (eg, diabetes, hypertension, and ulcers) and mental disorders (eg, anxiety disorder and depression) [5]. Patients with EDs have significantly higher mortality and suicide rates compared to the standard population [6,7]. The etiopathogenesis of ED is complex and not yet well understood. It may arise from the interaction of multiple risk factors, including genetic, neurobiological, psychological (eg, body image disturbances and personality disorders), developmental factors (eg, childhood sexual abuse), and sociocultural factors [8].

Given that EDs show great variability in their manifestation and severity, the treatment requires multidisciplinary collaboration of psychiatrists, psychologists, general practitioners, nutritionists (or endocrinologists), dieticians, nurses, and occupational therapists [2]. The treatments include medical nutritional support, pharmacological treatments, and psychological therapies. Cognitive behavioral therapies (CBTs) have been shown to be effective for the treatment of EDs and are considered the therapies of choice by psychologists for both treatment and ongoing support of patients with EDs [2]. Many therapists have observed telemedicine as an alternative to face-to-face therapy in extreme health situations, such as during the COVID-19 pandemic, although the availability of technological equipment for its administration has been uneven.

Telemedicine is the use of telecommunication systems to provide health care at a distance [9]. It involves the secure transmission of medical data and information via text, sound, images, or other forms necessary for the prevention, diagnosis, treatment, and monitoring of patients (EU Commission definition, COM {2008}689) [10]. Methods may vary in terms of the way the intervention is technically implemented, using tablets, smartphones, and computers, and the channels such as smartphone apps, websites, SMS text messaging, and vodcast, among others. In recent years, considerable progress has been made in the development and validation of psychological treatments administered through telecommunication systems. The popularity of telemedicine has increased rapidly in recent decades, and researchers have realized its potential in mental health and health in general. Telemedicine is a current trend as it is estimated that more than 50% of the population in high- and middle-income countries suffer from at least one mental disorder in their lifetime, with a significant impact on their quality of life [11].

Several factors have contributed to the growth in the adoption of telemedicine in health care, such as significant advances in communication technologies, the widespread use of high-speed internet, and the COVID-19 pandemic. The COVID-19 pandemic catalyzed the rapid and global adoption of telemedicine solutions in daily practice in all health care fields [12] due to the need for physical distancing and the shortage of health care professionals [13]. However, the implementation of telemedicine also raises technical and privacy concerns, including data security, patient confidentiality, cybersecurity vulnerabilities, and disparities in digital literacy and access to technology. Addressing these issues is crucial to ensuring the safe, ethical, and equitable delivery of care through telecommunication platforms [14-16]. The integration of technology into the study and treatment of EDs has taken many forms, including independent web-based intervention platforms, virtual reality interventions, smartphone apps, and technology-based treatment add-ons [17,18].

We aimed to evaluate the safety and effectiveness of telemedicine as a complementary tool for cognitive face-to-face therapies to promote adherence and monitoring in patients with an ED undergoing treatment.

We conducted a systematic review of the literature of telemedicine and EDs following the recommendations contained in the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting guidelines [19]. The research question was established in PICO (population, intervention, comparison, and outcomes) format. The review was conducted in accordance with a prespecified protocol, although this was not registered in a public database.

We searched the following health evaluation agency websites and databases: the National Institute for Health and Care Excellence, the Canadian Agency for Drugs and Technologies in Health (now known as Canada’s Drug Agency), MEDLINE (Ovid), Embase, Web of Science, Cochrane Library, international HTA database (International Network of Agencies for Health Technology Assessment), CINAHL (EBSCO), and PsycINFO (EBSCO). Structured and systematic search strategies specific to each resource consulted were constructed using free and controlled terminology to identify the relevant studies (Multimedia Appendix 1). The last update was conducted in December 2024 without temporal restrictions.

All identified references were initially filtered by title and abstract, and later, after full-text reading, using the following inclusion criteria: systematic reviews, synthesis reports, or meta-analyses studies that address telemedicine as a complementary therapy to face-to-face care; patients with an ED diagnosis and under treatment; and without language limits. Other study designs, editorials, letters to the editor, opinions, notes, surveys, consensus documents, conference abstracts, systematic reviews without assessment of the methodological quality of the included studies, and animal studies were excluded. A review of systematic reviews was selected to avoid redundancy and build on existing high-quality evidence.

The authors, country, year of publication, objectives, study design, patient characteristics, databases consulted, date of the search, intervention, time of follow-up, and result measures of the included studies were extracted and summarized in tables.

Two researchers performed an independent critical reading of the systematic reviews and assessed the risk of bias in the included studies, following the methodology established in AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews, version 2) [20]. Potential disagreements were resolved by consensus.

We performed a qualitative synthesis of the primary outcome measures following the reporting criteria established by the PRISMA guidelines [19]. We collected them in tables for the descriptive and narrative analysis. Although a meta-analysis was initially considered, the substantial heterogeneity in intervention types and outcome measures across the included studies made this approach inappropriate. A qualitative synthesis was chosen to provide a comprehensive overview of the available evidence.

A total of 1004 studies were initially identified from the search in the MEDLINE, Embase, CINAHL, Cochrane Library, Web of Science, PsycINFO, Canadian Agency for Drugs and Technologies in Health (now known as Canada’s Drug Agency) international HTA database, and National Institute for Health and Care Excellence databases and websites, but 184 (18.3%) duplicates were removed before screening. Therefore, 820 studies were included in the screening process. Figure 1 shows a flow diagram of the screening process and the reasons for exclusion. Briefly, 80.1% (657/820) of studies were excluded by title or abstract because they did not meet the inclusion criteria. The remaining 19.9% (163/820) studies were assessed for eligibility. After full-text reading, 96.9% (158/163) studies were excluded due to different reasons, such as different populations than the one studied, intervention not as a supplementary means, or lack of methodological quality assessment, among others. Finally, 5 studies were included in the review.

We identified 5 systematic reviews on telemedicine as a complementary tool to face-to-face care, published between 2011 and 2021. The characteristics of these systematic reviews are summarized in Table 1. These reviews varied in their intervention types, study populations, study designs, and geographic focus, reflecting the diverse landscape of telemedicine research in EDs.

The included reviews covered a wide range of telemedicine interventions, including email support (Aardoom et al [21] and Martin et al [16]), smartphone apps (Neumayr et al [34]), SMS text messages (Hay and Claudino [33]), and mHealth tools such as vodcasts (Anastasiadou et al [14]). These interventions were generally designed as adjuncts to face-to-face CBT, with a focus on providing motivational support, symptom monitoring, and psychoeducation.

The studies included in these reviews targeted various populations with EDs, including individuals with AN, BN, BED, and EDNOS. Most of the included studies focused primarily on women (513/617, 86.5%), although 2 reviews (Anastasiadou et al [14] and Neumayr et al [34]) included studies with both male and female participants, representing 13.52% of the total study population. This gender imbalance reflects the typical distribution of EDs but highlights the need for more inclusive research in this area.

The included systematic reviews incorporated a variety of study designs, including randomized controlled trials (RCTs), non-RCT experimental studies, observational case series, and crossover studies. Notably, there was some overlap in the primary studies included in these reviews. For example, the RCT by Hildebrandt et al [30] was included in the studies by both Anastasiadou et al [14] and Neumayr et al [34], while the observational case series studies by Yager et al [22,23] were included in the studies by both Martin et al [16] and Aardoom et al [21].

As summarized in Table 1, most of the included studies were conducted in high-income countries, including the United States, the United Kingdom, and Germany. This geographic concentration may limit the generalizability of the findings, as telemedicine interventions can vary significantly in their accessibility and effectiveness across different health care systems and socioeconomic contexts.

Several primary studies were included in the multiple reviews, highlighting the interconnected nature of the evidence base in this field. For example, the case series included in the reviews by Martin et al [16] and Aardoom et al [21] were largely overlapping, as were some of the experimental studies included in the reviews by Anastasiadou et al [14] and Hay and Claudino [33]. This overlap underscores the importance of carefully evaluating the quality and relevance of included studies to avoid double-counting evidence in future reviews.

Overall, the included reviews reflect a diverse but sometimes overlapping body of evidence on the use of telemedicine as a complementary tool for the treatment of EDs, emphasizing the need for more rigorous primary studies with broader population samples and more standardized outcome measures.

None of the 5 systematic reviews performed a meta-analysis. The methodological quality of the reviews was evaluated by applying AMSTAR-2 domains criteria [20] (Multimedia Appendix 2 [14,16,20,21,33,34]).

The systematic reviews by Martin et al [16] and Hay and Claudino [33] showed a moderate level of confidence. The main weaknesses were that they did not explicitly state that the review methods were established before the conduct of the review so that any significant deviation from the protocol could be justified [16], the exhaustive literature search strategy was partially presented [16,33], and their failure to explicitly provide the list of excluded studies and the justification for their exclusions [16,33]. Other methodological weaknesses found were related to the absence of information on the decision to include study design in the reviews analyzed [16,33], the failure to conduct peer selection or data extraction [16,33], and the absence of information on aspects related to the funding of the included studies 15,20]. The systematic reviews by Anastasiadou et al [14] and Neumayr et al [34] showed a low level of confidence. The main weaknesses were that they did not explicitly state that the review methods were established before the conduct of the review so that any significant deviation from the protocol could be justified [14,34], they partially presented the exhaustive literature search strategy [14,34], their failure to explicitly provide the list of excluded studies and the justification for their exclusions [14,34], and they did not explicitly provide the observed heterogeneity in the results of the review [14,34]. Other limitations found in these reviews were related to the absence of information on the decision to include the study design in the reviews analyzed and the absence of information on aspects related to the funding of the included studies. Finally, the systematic review by Aardoom et al [21] demonstrated a critically low level of confidence. The critical weaknesses were the failure to explicitly state that the review methods were established before the conduct of the review, making it difficult to justify any significant deviations from the protocol, as well as the absence of a predefined protocol. In addition, there was a partial lack of an exhaustive literature search strategy and a missing list of excluded studies, along with the reasons for their exclusion. Other identified limitations involved the lack of information regarding the decision to include specific study designs, the absence of peer selection or data extraction, and missing details about the funding of the included studies.

The systematic reviews did not find direct adverse effects of telemedicine interventions on patients’ health. However, Martin et al [16] and Anastasiadou et al [14] identified some patients’ concerns about computer privacy using email and smartphone apps, respectively; particularly, with the personalized nature of SMS text messages treatment of patients with AN and BN (Multimedia Appendix 3 [14,16,21]).

The next section first describes the modalities of the technological interventions and then presents them organized by the conditions addressed.

Table 6 synthesizes the main findings extracted from the 5 systemic reviews selected, presented by type of ED, study design, and telemedicine intervention.

Despite the global burden of EDs [1,3,4] and the rapid and global adoption of telemedicine solutions in health care [12], only 5 systematic reviews were identified that discuss telemedicine interventions as a complementary tool to face-to-face ED treatments [14,16,21,33,34]. These reviews encompass a high heterogeneity of primary studies, highlighting the need for more comprehensive research in this area.

Regarding the effectiveness of these interventions, promising outcomes were observed, as presented in Textbox 1.

This study identified email, vodcasts, smartphone apps and SMS text messaging as the principal telemedicine channels offering patients access and adherence to treatment, improving patient-physician communication, and increasing patients’ motivation. In most cases, patients highlighted the usefulness of telemedicine interventions. However, security and privacy issues remain a challenge, as some patients expressed concerns about the use of email and smartphone apps. Patients with EDs, who often struggle with distorted self-perception, may be particularly sensitive to privacy concerns [14].

Although none of the systematic reviews identified direct adverse effects of telemedicine interventions on patients’ health, concerns about privacy in the use of email and smartphone apps were noted. Furthermore, while no technical or organizational problems were explicitly reported in the studies, the scientific literature highlights potential issues, such as technical problems [14], sound and video quality [16], difficulties in ensuring privacy (of parents and children), lack of adequate devices for telemedicine access, and connectivity problems [15]. These factors could impact the effectiveness and safety of telemedicine interventions.

No direct adverse effects of telemedicine intervention on patients’ health were disclosed, although concerns about privacy in the use of email and smartphone apps were identified in some patients [14,16].

Telemedicine intervention showed promise as a complementary tool for face-to-face ED treatment with potential benefits for both patients and health care systems. However, it is important to acknowledge that most primary studies included in the systematic reviews were observational case series and non-RCTs, which limited the quantitative data on effectiveness. This highlights the urgent need for further high-quality research in this field. The systematic review by Anastasiadou et al [14] highlighted the RCT study by Hildebrandt et al [30], which found that smartphone apps as an adjunct ED therapy in heterogeneous study populations increased BMI. These findings are particularly significant for patients with BN and BED, who are often overweight.

In terms of treatment adherence, some primary studies revealed a promising 87% retention rate among patients with BN who used SMS text messaging [29] and 78.8% among patients with BN and BED who used the Noom monitor app [30]. However, it is important to note that the potential efficacy of telemedicine in promoting treatment adherence is an area that requires more research, as the RCT [30] did not find differences in patients with BN and BED using the smartphone app compared with the control group.

The methodological quality of systematic reviews revised in this study ranged from moderate to critically low. This variation in confidence levels could potentially impact the risks of bias in their results. However, it is important to note that the AMSTAR-2 tool, which we used for this evaluation, does not consider the quality of the studies included in each document. Most of the primary studies included in the selected systematic reviews were observational studies with a small number of patients, leading the authors of the systematic reviews to classify them as low quality. We identified only 2 RCTs and 3 experimental studies among the 5 systematic reviews. It is worth mentioning that 2 case series and 2 RCTs were duplicated in some of the identified systematic reviews. The primary studies also had a limited number of interventions for the control group.

Given the limited literature specifically focused on EDs, it is also important to consider the findings of research on other mental health conditions. EDs frequently co-occur with psychiatric diagnoses, such as anxiety disorders, major depressive disorder, and obsessive-compulsive disorder, and share overlapping risk factors and symptomatology. Evidence from studies on these conditions has shown that telemedicine can be effective in supporting symptom monitoring, improving treatment engagement, and facilitating access to care, particularly in underserved populations. These broader findings may offer valuable insights into the potential benefits and limitations of telemedicine-based interventions for individuals with EDs, especially when comorbidities are present. Future studies on EDs should take this into account and incorporate more integrated approaches that address both EDs and commonly associated mental health disorders.

The main limitation of our study is the limited number of systematic reviews identified that analyzed the effects of telemedicine interventions on face-to-face therapies in patients with ED. Overall, these systematic reviews showed a wide heterogeneity in the study designs, telemedicine interventions, ED conditions in the study population, follow-up periods, and outcome measures included in their selected primary studies. This heterogeneity undermines the quality level of of confidence and reduces the robustness of efficacy conclusions.

The studies included in this review were primarily conducted in high-income countries, such as the United Kingdom, the United States, and Germany. This geographical concentration likely reflects where telemedicine infrastructure is more established, funding for mental health research is more readily available, and digital health interventions are more commonly integrated into clinical practice. As a result, the findings may not be fully generalizable to low- and middle-income countries, where access to technology, internet connectivity, and specialized care for eating disorders remains limited. Socioeconomic disparities must therefore be considered when interpreting the applicability of telemedicine as a complementary approach in more diverse global settings.

The heterogeneity of telemedicine intervention channels and ED conditions in the study population challenges the establishment of robust studies. More RCTs are needed to evaluate the usefulness and clinical efficacy of telemedicine interventions as complementary tools for face-to-face therapies in patients with EDs. Recording data based on established tools, such as assessment tools in EDs [35], may allow better analysis and comparison of the results.

Although few studies have evaluated telemedicine as a complementary treatment to face-to-face therapies, existing evidence suggests that this approach is promising for the treatment of EDs in youth. Previous studies have shown that telemedicine, particularly internet-based interventions such as internet-based CBT, can significantly improve pathological eating behaviors and reduce binge episode frequency in patients with binge-spectrum eating disorders [36,37]. Moreover, while further research is needed, especially regarding the use of videoconferencing and mobile apps, current findings support its potential as an effective tool within the therapeutic framework [38-41].

Although the reviewed studies suggest that telemedicine can improve treatment adherence and patient-clinician communication, evidence on its long-term impact on recovery and relapse prevention is limited. Studies with extended follow-up periods are needed to assess whether the short-term benefits persist over time.

In our review, 5 systematic reviews were identified that reported telemedicine as a complementary treatment to face-to-face therapies. The telemedicine tools identified in the included studies were vodcasts, SMS text messaging, smartphone apps, and email.

The synthesis of the results was carried out qualitatively due to the significant heterogeneity of the interventions, the population included, and different outcome measures and follow-up periods. It should be noted that the studies included in the reviews identified for analysis were of various designs and that the quality of the evidence reviewed was low or moderate. Tables 2-6 provide a detailed summary of the results and the quality of the included studies that can be used for the correct interpretation of the following conclusions:

Despite these potential benefits, the overall quality of the evidence remains limited, with most included studies being observational case series with small sample sizes, leading to moderate to low confidence in the overall findings. Further high-quality research is needed to confirm the effectiveness of telemedicine as a complementary treatment for EDs.