Research on men's body self-image shows they are more concerned by what other men think of their bodies than what their sexual partners think.
Victoria University Doctorate of Clinical Psychology graduate Dr Annabel Chan Feng Yi surveyed 738 men online and found insecurity about weight, body image and penis size common.
"Men's pre-occupation with size was rarely to do with pleasing sexual partners or even appearing as a better sexual partner," Dr Chan said.
"It was often more about competition with other men. Many felt most insecure about their size in environments where other men might see them, such as gym change rooms."
The men surveyed ranged in age from 18 to 76 years old.
She said the same men who experienced 'locker room syndrome' mostly reported they were in fact happy with their size when it came to personal satisfaction and that of their sexual partners.
An obsession with building up muscle was also common, especially among gay respondents.
"The research demonstrates that societal pressures on body image are certainly not unique to women and that while men share similar body image concerns they often don't have the appropriate forum to discuss them or adequate professional support to deal with them," she said.
"There is clearly a need to provide more research-based training for clinicians working in this field and public awareness to de-mystify and de-stigmatising the topic of male body image."
The research also highlighted an urgent need to incorporate the experience of men facing obesity issues and its implications in further research, instead of the current one-sided focus on men's drive for muscularity, she said.
Dr Chan's Doctorate supervisor was Professor Gerard Kennedy and the research originally completed as part of her Doctorate of Clinical Psychology late 2012. She has been discussing the research this week on ABC Radio and other media during National Men's Health Week, which runs June 10-16.