Lead author Terri Fisher of the Ohio State University Mansfield campus said the study discredits the persistent stereotype that men think about sex every 7 seconds, which would amount to more than 8,000 thoughts about sex in 16 waking hours.
The study, scheduled to be published in the January print issue of the Journal of Sex Research, found the median number of young men's thought about sex stood at almost 19 times per day, while young women reported a median of nearly 10 thoughts about sex per day.
As a group, men thought about food almost 18 times per day and sleep almost 11 times per day, compared to women's median number of thoughts -- about 15 for eating and 8.5 for sleep -- the study said.
The study involved 163 female and 120 male college students ages 18- 25 -- 59 randomly assigned to track thoughts about food, 61 about sleep and 163 about sex.
Researchers gave each student a tally counter and told those assigned to the sexual thoughts condition to click the device for every sex thought, including sexual activity of any kind, fantasies and erotic images, sexual memories and any arousing stimuli.
Fisher said previous research about sexual thoughts might differ from her study, which involved actual tallies of thought, while older research was based on participants' retrospective estimates in a questionnaire.