Everybody knows that men think about sex every seven seconds. What people haven’t perhaps considered is that means more than 8000 times a day or 56 000 times a week. Despite the joke that if men only think about sex every seven seconds what on earth do they think about the rest of the time, that’s a lot of mental energy devoted to sex. The selfish gene may demand that we reproduce, but 8000 thoughts a day on sex is surely excessive. (But then again the average ejaculate contains around 300 million sperm, which seems even more excessive.) So can it be true that men think about sex 8000 times a day?

One of the best shows on radio, More or Less, considered the question last week, and I heard most of the broadcast and found a newspaper report of the study the programme featured. I also found a copy of the abstract of the article in the Journal of Sex Research, but I wasn’t willing to pay £23.50 to access the full article.

Professor Terri Fisher from Ohio State University led the study and featured in the programme. Her first unsurprising point was that she could find no research that backed up the claim that men thought about sex every seven seconds. It is, she suggested, an urban myth, a popular one.

She conducted a study with her students—160 women and 120 men aged 18 to 25. They were randomly divided into three groups, given a golf tally counter, and asked to record how often they thought about sex, food, or sleep over a week. Professor Fisher accepted that this is an imperfect method but better, she argued, than asking somebody how often they had thought about sex in the past hour, day, or week.

My wife made the point that every time you felt the counter in your pocket you’d think about sex, food, or sleep because you’d been told to, so there would be some sort of weird feedback. It’s a little like being told not to think about a rhinoceros: you immediately think of a rhinoceros.

But Professor Fisher had defined what she meant by “thinking about sex”: she meant intercourse, nudity, something with erotic content, not just the word sex.

The men thought about sex between one and 388 times a day with a median of 18, well short of 8000. I perhaps give myself away when I marvel at the young man who had only one sexual thought in a day: did he not look around? But 388 times, roughly once every two minutes, is good going. Perhaps he was on his way to somewhere interesting, or perhaps he spent most of the day having sex, not unknown among students: in which case 388 times might be considered inattentive.

The women did, as society expects, think about sex less with a range of one to 140 times and a median of 10.

The men also thought more than the women about food (18 to 15) and sleep (11 to 8.5). So men think about food as much as sex, something my wife found unsurprising. I was equally unsurprised that women think more about food than sex.

As most of us eat three meals a day seven days a week it would be very hard to avoid thinking about food unless you could prepare and eat it without thinking about it. In contrast, very few of us have sex three times a day seven days a week. Then the thought of food is not as satisfying as the actuality, whereas it may be the other way round for sex.

It’s hard to know how to interpret these, but how about this hypothesis: men just have more thoughts than women.

Richard Smith was the editor of the BMJ until 2004 and is director of the United Health Group’s chronic disease initiative.