Muscle-building supplement use is associated with muscle dysmorphia symptomatology among Canadian adolescents and young adults.

This study investigated the association between muscle-building supplement use and muscle dysmorphia symptomatology among Canadian adolescents and young adults. Data from the Canadian Study of Adolescent Health Behaviors (N = 2,731) were analyzed. Multiple linear and logistic regression analyses were used to assess the association between six commonly used muscle-building supplements (e.g., amino acids/branched-chain amino acids, creatine monohydrate, pre-workout drinks or powders, protein bars, weight/mass gainers, and whey protein shakes or powders), and an aggregated sum score of muscle-building supplements used, and muscle dysmorphia symptomatology (measured using the Muscle Dysmorphic Disorder Inventory [MDDI]), including scoring above the clinical cut-off (≥ 40 on the MDDI). The mean age of the sample was 22.9 years (SD = 3.9), 54.3% identified as a cisgender girl or woman, 62.4% identified as white, and 58.8% identified as heterosexual. Findings revealed that use of all six muscle-building supplements, and using a greater number of muscle-building supplements, were associated with greater total muscle dysmorphia symptomatology, as well as greater odds of meeting the clinical cut-off for muscle dysmorphia. These findings add to a growing body of literature on the association between muscle-building supplement use and muscle dysmorphia symptomatology by including multiple muscle-building supplements and utilizing a diverse, national sample of adolescents and young adults. Findings warrant further investigation and the development of intervention strategies to decrease the use of increasingly normalized muscle-building supplements and muscle dysmorphia symptomatology.