# Orthorexia nervosa and exercise addiction: distinct entities beyond restrictive and muscularity-oriented disordered eating behaviours?

## TL;DR

The study explores whether orthorexia nervosa and exercise addiction are distinct disorders or just extreme forms of disordered eating behaviors.

## Contribution

The study investigates the unique psychological and behavioral links of orthorexia and exercise addiction beyond disordered eating patterns.

## Key findings

- Orthorexia nervosa is strongly linked to psychological distress and impairment, both directly and through disordered eating.
- Exercise addiction's association with impairment is largely explained by muscularity concerns rather than being a distinct addiction.
- Both conditions show significant overlap with disordered eating behaviors, challenging their status as separate disorders.

## Abstract

Orthorexia Nervosa (OrNe) and Exercise Addiction (EA) are potentially dysfunctional variants of health-oriented behaviours, but their status as distinct mental disorders remains debated. OrNe is the obsessive preoccupation with ‘healthy’ eating, whereas EA is characterized by loss of control over exercise and prioritization over other life domains. Both commonly coincide with disordered eating, raising the question whether the clinical indicators are inherent to OrNe and EA or primarily reflect overlapping eating pathologies. This study examined whether OrNe and EA are distinct from restrictive and muscularity-oriented disordered eating by assessing their overlap and their unique links to psychological distress and psychosocial impairment.

Within a cross-sectional web-based study, 384 participants (age = 31.5±11.5; 76.3% women) completed the Teruel Orthorexia Scale (TOS), Exercise Dependence Scale Revised (EDS-R), Eating Disorder Examination-Questionnaire (EDE-Q), Muscularity-Oriented Eating Test (MOET), Brief Symptom Inventory-18 (BSI-18), and Clinical Impairment Assessment Questionnaire (CIA).

Bivariate correlation analyses revealed strong overlaps of TOS-OrNe with both forms of disordered eating (EDE-Q: r = .635, MOET: r = .730), which were significantly more pronounced in women (EDE-Q: r = .676, MOET: r = .810) than men. EA was strongly correlated with MOET (r = .536), and weakly with EDE-Q (r = .242). Multiple regression and path analyses showed OrNe predicted psychosocial impairment and psychological distress both directly and mediated by EDE-Q, whereas EA was not uniquely linked to clinical indicators. Exploratory factor analysis further suggested strongly related latent constructs.

Although OrNe was uniquely associated with psychological distress and impairment, its substantial overlap with restrictive and muscularity-oriented disordered eating challenges its validity as a distinct disorder. EA’s association with impairment appears largely explained by muscularity concerns, questioning its conceptualization as a behavioural addiction. These findings underscore the importance of considering muscularity-related motives and behaviours in both research and clinical assessment. Overall, OrNe and EA may reflect socioculturally shaped expressions of disordered eating rather than independent mental disorders.

The online version contains supplementary material available at 10.1186/s40337-026-01535-8.

Healthy eating and regular exercise usually support well-being, but for some people, focusing on these behaviours too intensely may cause problems in daily life. Two patterns that have received attention are Orthorexia Nervosa (OrNe) and Exercise Addiction (EA). OrNe involves being strongly focused on eating only ‘healthy’ foods, while EA involves a strong need to exercise, prioritizing it over work, family, or other daily activities. These behaviours often overlap with disordered eating, such as strict dieting or a focus on building muscle, so it is unclear whether any distress or daily-life problems are caused by OrNe and EA themselves or by disordered eating. Our study examined how much OrNe and EA are linked to restrictive and muscle-focused eating patterns and whether they contribute to mental health problems. We found that both OrNe and EA strongly overlap with these eating behaviours, meaning that people with these patterns are also likely concerned with thinness or muscularity. EA alone does not seem to cause mental health problems beyond those associated with disordered eating. Regardless of how these behaviours are classified in research, anyone who experiences distress or difficulties because of their eating or exercise habits may benefit from seeking professional support or treatment.

The online version contains supplementary material available at 10.1186/s40337-026-01535-8.