Men eat significantly more food when sharing a meal with women than with other men, a new study suggests.

For the study, which was published online in the journal Evolutionary Psychological Science, researchers observed 105 adults that were eating lunch at an all-you-can eat Italian buffet located in the northeastern U.S. over the course of two weeks.

The researchers recorded how many pizza slices and how many bowls of salad each diner ate. They also recorded the gender of each diner, and the gender of the diner's companion or companions.

Before each diner left the restaurant, they were approached by a researcher and asked to fill out a short survey. The survey asked questions to assess their level of fullness, their feelings of hurriedness and their general comfort while eating.

The study found the following:

  • Men who dined with at least one woman ate 93 per cent more pizza and 86 per cent more salad than men who dined with only other men;
  • The amount women ate didn't change when they dined with other women or with men;
  • When they dined with men, many women said that they overate and felt that they were rushed through their meal.

Kevin Kniffin, a behavioural scientist at Cornell University and the study's lead author, said the results suggest that men may be trying to prove something when eating in the company of women.

"These findings suggest that men tend to overeat to show off – you can also see this tendency in eating competitions which almost always have mostly male participants," he said in a statement.