How common are eating disorders in adults seeking obesity treatment?
In 2022, the global prevalence of obesity in adults (≤18 years) was around 16%, more than double what it was in 1990 (World Health Organization, 2025). Adults with obesity are more at risk for disordered eating and eating disorders (EDs), with binge-eating and binge-eating disorder (BED) the most frequently studied (Da Luz et al., 2018).
Research on other EDs is less extensive. However, a systematic review from 2021 reported atypical anorexia nervosa (AAN; having the symptoms of anorexia without being underweight; read Eleana’s blog to learn more) to be present in 0.15% to 13% of females with obesity. Interestingly, this was more prevalent than those presenting with anorexia with low weight within the community, yet was referred for ED care less often (Harrop et al., 2021).
As such, research has found that adults with EDs are more likely to receive weight-loss treatment over treatment for their ED (Hart et al., 2011; Kaur et al., 2022; Palavras et al., 2011). This is a cause for concern, as it suggests that this population of individuals with EDs are not receiving appropriate care.
However, evidence for the full spectrum of EDs and disordered eating behaviours is lacking. There needs to be a more complete understanding of how prevalent EDs are amongst adults seeking obesity treatment, as it is currently difficult to determine the type and scale of mental health support needed. Therefore, the aim of this systematic review and meta-analysis (Melville et al, 2025) was to estimate the prevalence of disordered eating and EDs in adults seeking treatment for obesity.
Most research so far on the prevalence of eating disorders in those with obesity has focused on binge-eating disorder and binge-eating behaviours, meaning a substantial portion of the picture is missing.
Methods
Three databases were searched for studies that contained:
- Adults or a mixed sample of adolescents and adults where the mean age was ≥18 years with either an overweight or obese BMI.
- Those seeking obesity treatment.
- A diagnosis of an ED or disordered eating behaviour by clinical interview or validated questionnaire at the time of entry into obesity treatment.
- A minimum sample size of 325 participants.
All EDs and disordered eating behaviours (e.g., loss of control eating, drive for thinness) were included. Studies were excluded if they contained participants (1) seeking both obesity and ED treatment, or (2) with obesity as part of a broader syndrome. Foreign language studies were translated using Google Lens so that they could also be included.
Studies were double screened independently by four authors. Data was independently extracted from included studies by two reviewers and methodological quality of studies was independently assessed by one reviewer, with accuracy checks by another reviewer.
A random-effects model was used in the meta-analysis to pool prevalence estimates of EDs and disordered eating behaviours. Subgroup analyses and tests for publication bias and small study effects were also conducted.
The review was prospectively registered on PROSPERO (CRD42023461340) and reported in accordance with the JBI Manual for Evidence Synthesis and PRISMA guidelines.
Results
Study characteristics
Eighty-five studies were included in this systematic review, published between 1985 and 2025. Most studies were published either in the USA (n = 43) or Italy (n = 17). Data came from 94,295 participants (75.9% female, median age = 44 years [IQR = 5], median BMI = 46 kg/m2 [IQR = 10]). The most reported obesity treatments were bariatric surgery (n = 49), behavioural weight management (n = 9), or multiple treatment options (n = 8).
Prevalence rates were reported for multiple EDs and disordered eating behaviours, but BED (n = 46) and self-report binge eating (n = 32) were the most common. No studies reported on avoidant/restrictive food intake disorder, pica, rumination, or purging disorder.
Prevalence estimates
BED and binge eating behaviours
For those reporting BED, the pooled prevalence was:
- 17% (95% CI [12 to 22], 19 studies) as assessed by clinical interview using DSM-IV criteria with a prediction interval (an estimate of where a future observation will likely fall) of 0% to 42%.
- 14% (95% CI [7 to 22], 10 studies) when assessed by DSM-5 criteria with a prediction interval of 0% to 43%.
- 12% (95% CI [9 to 16], 17 studies) from self-report questionnaires.
The authors also found evidence of publication bias and small study effects for all three BED prevalences, where the prevalence of BED increased as the study sample decreased.
For those reporting binge eating behaviour according to the Binge Eating Scale, the pooled prevalence was:
- 26% (95% CI [23 to 28], 12 studies) for moderate binge eating severity with a prediction interval of 18% to 33%.
- 12% (95% CI [8 to 16], 18 studies) for severe binge eating severity with a prediction interval of 0% to 31%.
- However, severe self-report binge eating was re-examined following the removal of one study from 1985 (Marcus et al., 1985) due to this study being an outlier. Following the removal of this study, the pooled prevalence was 10% (95% CI [8 to 12], 17 studies) with a prediction interval of 2% to 19%.
Again, there was a possibility of bias for self-report severe binge eating, but this was not found for moderate severity self-report binge eating behaviour.
Other EDs
When assessed by clinical interview, the pooled prevalence of:
- Night eating syndrome was 5% (95% CI [2 to 9], 5 studies) with a prediction interval of 0% to 17%.
- Bulimia nervosa was 1% (95% CI [0 to 1], 9 studies) with a prediction interval of 0% to 2%.
- Disorders where the type was not specified was 11% (95% CI [4 to 18], 9 studies) with a prediction interval of 0% to 36%.
Only two studies reported AAN, with the prevalence 0.2% in one study assessed by clinical interview (Lin et al., 2013). The second study had no reported cases (Hilbert et al., 2022). Egger’s tests were significant for bulimia nervosa and eating disorders when not specified, indicating possible evidence of bias where prevalence increased as study sample size decreased.
Sensitivity analyses
Post-hoc sensitivity analyses examined the potential bias of smaller studies, given that prevalence estimates commonly increased as study sample sizes decreased. Aside from BED when assessed by DSM-5 clinical interview, tests remained significant when the minimum sample size increased, demonstrating that prevalence tended to decrease with larger samples.
Meta-regression
The final year of data collection was found to be significantly associated with the prevalence of self-report severe binge eating, where binge eating decreased over time (p < 0.01).
Subgroup-analyses
Various post-hoc subgroup analyses were conducted, including treatment type, clinical interviews, and sex, but no significant differences were found.
Quality assessment
Whilst no studies were excluded based on the quality assessment, insufficient reporting meant that two domains were often selected as ‘unclear’: (1) the reliability of measurements and (2) clearly described response rates.
Binge eating disorder and binge eating behaviour remained the most studied outcomes in the context of obesity treatments, with a few studies reporting prevalence rates on night eating disorder, bulimia nervosa, and atypical anorexia nervosa.
Conclusions
This was the first comprehensive review to estimate the prevalence of both EDs and disordered eating behaviours within adults seeking treatment for obesity. Overall, research has mainly focused on BED and binge-eating behaviours, with limited research on other types of EDs or disordered eating behaviours.
As such, this review estimates that:
- approximately 14% of adults seeking obesity treatment may also have binge-eating disorder (BED),
- an estimated 26% may have self-reported moderate binge-eating,
- 5% may have night eating syndrome, and
- 1% may have bulimia nervosa.
Binge-eating disorder occurs in approximately 14% of adults seeking treatment for obesity, with 26% reporting moderate binge-eating. Research on other types of eating disorders and disordered eating behaviours is limited.
Strengths and limitations
This study had various strengths, including but not limited to:
- The use of rigorous methods. This review identified articles from multiple relevant databases, employed double independent screening methods, contacted authors of eligible studies for missing information, and investigated potential publication and small sample biases. Strategies such as this help to ensure that relevant studies are not missed, and that conclusions are reliable.
- The cumulative sample was large, containing over 94,000 people from 85 studies, spanning multiple countries over 40 years. This helps to make the prevalence estimates more reliable, representative, and useful in terms of informing screening of obesity treatments in the future.
- The use of prediction intervals as well as confidence intervals also improves transparency and future applicability, as it helps to estimate what prevalence might be in future studies.
Despite this, there were still some limitations:
- Whilst the sample was large, some groups remained underrepresented. For example, most participants were White, and from higher socioeconomic backgrounds. Also, only participants who were actively seeking obesity treatment were included in this study. All of this prevents us from being able to generalise to other populations (e.g., untreated individuals) where prevalence might differ.
- There was an underrepresentation in some treatment settings, with most studies reporting on bariatric surgery. This means that other, non-surgical treatments, were likely underpowered which might result in misleading conclusions, or a bias towards specific treatments (such as surgery). However, the authors set a minimum sample size of 325 participants in each study to help alleviate this.
- Prevalence estimates might also be influenced by changes in treatment types and diagnostic criteria over time (e.g., use of DSM-IV to DSM-5), given the 40-year data span included within this study. This means that the same ED might be identified or classified differently over time, potentially influencing prevalence estimates and making comparisons across time less valid.
This review used rigorous methods to capture prevalence information on eating disorders and disordered eating behaviour across a 40-year span, including over 94,000 participants.
Implications for practice
Given the estimated prevalence of EDs and disordered eating behaviours co-occurring with obesity, routine screening of ED symptoms should be conducted before entry into obesity treatment programmes to ensure individuals are referred for the most suitable treatment. It would be beneficial if this screening coincides with further training of clinicians within these programmes to recognise signs and symptoms of EDs, including binge eating and BED, alongside other EDs found to be prevalent in this review’s population, such as night time eating and bulimia nervosa. This would help to identify not only the presence of an ED but what type, to assist in decisions around most suitable treatment.
Further research in this area is also needed. Firstly, research on the most effective treatment pathways for individuals with co-occurring obesity and EDs/disordered eating is important, to ensure appropriate care and improved long-term outcomes. There should also be an investment in research with under-researched populations, such as ethnic minority groups, those who have not sought formal treatment, or those seeking non-surgical or community-based treatments, to further understand prevalence rates within these populations. Without such research, our understanding of the prevalence of EDs within this population is limited and cannot be generalised to individuals from these groups. To support this, obesity treatment programmes could also implement prevalence monitoring as standard, to further understand prevalence rates over time.
Routine screening of eating disorders and disordered eating behaviours should be implemented as part of routine screening to obesity treatment programmes, to identify and support individuals in receiving the most appropriate care.
Statement of interests
None.
Links
Primary paper
Melville, H., Lister, N. B., Libesman, S., Seidler, A. L., Cheng, H. Y., Kwan, Y. L., Garnett, S. P., Baur, L. A., & Jebeile, H. (2025). The Prevalence of Eating Disorders and Disordered Eating in Adults Seeking Obesity Treatment: A Systematic Review With Meta‐Analyses. International Journal of Eating Disorders, 58(9), 1644–1661. https://doi.org/10.1002/eat.24483
Other references
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Frisira, E. (2023). “You Don’t Look Anorexic”: unmasking weight stigma in patients with atypical anorexia nervosa. The Mental Elf.
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