bigorexia
noun [ U ] uk/ˌbɪɡ.əˈrek.si.ə/ us/ˌbɪɡ.əˈrek.si.ə/
（一种精神疾病，常见于男子）恐瘦症，增大围度欲望
a mental illness in which someone, usually a man, worries that their body is too small and weak and tries to eat only foods that they believe will build bigger muscles