The surprise was the men – think of a group of guys holding back on the wings at a tailgate party or a Superbowl pigout. But when men sat with other men, they ordered an average of only 952 calories. When they sat with women, they ordered 1162 calories.

Allen-O’Donnell and Cottingham also acknowledged it was possible that unconscious scripts about how much to eat were at work when people sat down to a meal with someone of their own sex, not just when people sat down with someone of the opposite sex.

None of the participants that Allen-O’Donnell spoke with said they were aware that the gender of their dining partners affected how much food they purchased.