Background: Muscle dysmorphia (MD) is associated with a self-perceived lack of size and muscularity, and is characterized by a preoccupation with and pursuit of a hyper-mesomorphic body. MD symptoms may hypothetically be more prevalent in bodybuilders (BBs) than in non-bodybuilder resistance trainers (NBBRTs).
Objective: Our objective was to compare MD symptomatology in BBs versus NBBRTs and identify psychological and other characteristics associated with MD in these groups.
Methods: We searched relevant databases from earliest record to February 2015 for studies examining MD symptoms in BBs and/or NBBRTs. Included studies needed to assess MD using a psychometrically validated assessment tool. Study quality was evaluated using an adapted version of the validated Downs and Black tool. We calculated between-group standardized mean difference (effect sizes [ESs]) and 95 % confidence intervals (CIs) for each MD subscale, and performed meta-analysis when five or more studies used the same MD tool. We also extracted data describing psychological or other characteristics associated with MD.
Results: Of the 2135 studies initially identified, 31 analyzing data on 5880 participants (BBs: n = 1895, NBBRTs: n = 3523, controls: n = 462) were eligible for inclusion, though study quality was generally poor-moderate (range 7-19/22). Most participants were male (90 %). Eight different MD assessment tools were used. Meta-analysis for five studies all using the Muscle Dysmorphia Inventory (MDI) revealed there was a medium to large pooled ES for greater MD symptomatology in BBs than in NBBRTs on all MDI subscales (ES 0.53-1.12; p ≤ 0.01). Competitive BBs scored higher than non-competitive BBs (ES 1.21, 95 % CI 0.82-1.60; p < 0.001). MD symptoms were associated with anxiety (r 0.32-0.42; p ≤ 0.01), social physique anxiety (r 0.26-0.75; p < 0.01), depression (r 0.23-0.53; p ≤ 0.01), neuroticism (r 0.38; p < 0.001), and perfectionism (r 0.35; p < 0.05) and were inversely associated with self-concept (r -0.32 to -0.36; p < 0.01) and self-esteem (r -0.42 to -0.47; p < 0.01).
Conclusions: MD symptomatology was greater in BBs than in NBBRTs. Anxiety and social physique anxiety, depression, neuroticism, and perfectionism were positively associated with MD, while self-concept and self-esteem were negatively associated. It remains unclear whether these characteristics are exacerbated by bodybuilding, or whether individuals with these characteristics are attracted to the bodybuilding context.