Scientists say this alarming level of male ignorance is fuelling an obesity epidemic.
They say labelling must be made clearer to prevent lifestyle-related illnesses.
Lead author Claire Duffy, a master of science in preventive cardiology based in Ireland, explained: “People find food labels confusing and don’t know what to look for. They still have difficulty understanding and interpreting them.”
The study, presented at a meeting of the European Society of Cardiology in Munich, was based on a survey of 200 Irish men and women of all ages.
They had answered a questionnaire which was devised by Ms Duffy.
The research found one in three men “always or often” look at labels, compared with two in three women.
As well as identifying this gender gap, those most at risk of heart disease were also most likely to be confused by the salt, fat and sugar content signs.
However, most volunteers successfully deciphered a “traffic light” food label.
“You would think people with high cholesterol would check the saturated fat content on food labels, but that did not always happen,” Ms Duffy said. “Food labels need to be improved.”