Thinness and muscularity internalization: Associations with disordered eating and muscle dysmorphia in men

The tripartite influence model of body image identifies internalization of societal body ideals as a risk factor for developing body dissatisfaction, and subsequent disordered eating behavior. In men, internalization of two dimensions of body image ideals, thinness and muscularity, is associated with body dissatisfaction and eating concerns. However, it is unknown how thinness and muscularity internalization interact in predicting muscle dysmorphia and disordered eating in men.

Data were collected online from 180 undergraduate men, with ages ranging from 18 to 33 years (19.6, SD = 2.6). Regression models were used to test the interactive effects of thinness and muscularity internalization on (a) muscle dysmorphia symptoms and (b) disordered eating. Subsequent simple slope analyses probed effects at the mean, and ±1 standard deviation of thinness internalization.

Muscularity and thinness internalization were independently positively related to muscle dysmorphia symptoms and disordered eating. Additionally, a significant interaction revealed that muscularity internalization was increasingly related to muscle dysmorphia symptoms as thinness internalization decreased.

Men who internalized the muscular ideal had higher levels of muscle dysmorphia when they did not highly internalize the thin ideal. However, greater internalization of both the muscularity and thin ideal independently may be most relevant in the development of disordered eating in men. Future research is needed to explore variability in experiences of muscle dysmorphia compared with disordered eating in males.