Dear Cecil: I keep hearing about some study showing that a bunch of secretaries gained an average of 20 pounds when they switched from manual to electric typewriters back in the 60s. But I can't find any citation. Can you? Is this true? I guess I should have typed this on my old manual typewriter and posted you the letter. Guess I'll stay fat. Ivana Begley, Seattle

Cecil replies:

To be honest, this is one of the more benign factoids making the rounds of the Internet. It doesn’t involve antisocial behavior, embarrassing the Walt Disney Company, or the loss of critical body parts. It even imparts a medically desirable lesson, namely that lack of exercise is a big reason why Americans are porking up. Sure, if you want to get anal about it, it’s wrong. But there’s a sliver of truth to it, and the process by which that sliver was built up into a durable Internet legend makes for an instructive tale.

The story shows up multiple places in print and online and involves considerable variation. The alleged number of calories the secretaries ceased to burn upon switching from manual typewriters to electrics ranges from 60 calories per day to 200, the resultant weight gain from 4 pounds to 20. When a time frame is specified for this epidemic, it may be the 1940s, the 1950s, or occasionally the year 1960.

One weight-loss advocate and author, Kim Bensen, struck us as particularly energetic in warning of the dangers of electric typewriters. She consistently claims secretaries who’d made the switch burned 200 fewer calories a day, although she goes back and forth on when exactly it all happened — sometimes it’s the ’40s, sometimes the ’50s. We tried to contact her to clear things up but never heard back.

No matter. We found the study that’s undoubtedly the source of this nutty idea.

It was a report published in the Journal of the American Medical Association (JAMA) in 1958. Provocatively titled “Metabolic Demands as a Factor in Weight Control,” the article pointed out that either of two key elements could contribute to putting on weight — food intake going up or energy consumption going down. Deciding the latter had received insufficient attention, the researchers gave examples of seemingly minor changes in activity that could add up to significant weight gain over time.

For instance, sitting burned nine fewer calories per hour than standing up. A 5-foot-10, 150-pound farmer burned 126 calories per hour driving a tractor with power steering versus 157 calories driving one with manual steering.

And then there was typing. A 5-foot-3, 120-pound individual, the JAMA researchers contended, used up 88 calories per hour operating a mechanical typewriter compared to 73 calories per hour on an electric. Assuming six hours of typing per day, that meant 450 fewer calories burned per week. If all else stayed the same, she’d gain a pound every 10 weeks, or five pounds a year.

Where had JAMA come up with its numbers on typists’ energy expenditure? Burrowing through the endnotes, we find a reference to a Scottish journal article from 1955, which in turn cites a 1954 Italian paper in which three eminenti dottori speak of their studio sul consumo energetico delle dattilografe con macchina meccanica ed elettrica … sorry. We learn that six young women were found to consume, on average, 1.39 calories per minute pounding on a manual typewriter at 30 wpm but just 1.16 calories doing the same on an electric — a little lower than the JAMA figures, technically, but in the ballpark.

Crucially, though, no effort was made to determine if the typists actually gained weight as a result of this differential. Rather, we’re told, “these measurements were made over several 10-minute periods.” From this scant fact set all else had been extrapolated. In other words, JAMA‘s stern warning about health consequences was based on less research than goes into the average high school science fair project.

Still, from a gender standpoint the JAMA researchers had been, considering the times, surprisingly fair, providing examples of potential weight gain in both male- and female-dominated occupations, namely farming and typing. The media made short work of that once the study was released, ignoring the farmer and concentrating on the typist. “Scientists Warn Slim Stenos May Bulge if Mechanized,” read the Wall Street Journal headline, which to me suggests a robotics experiment gone horribly wrong. The lead sentence was clearer: “Think twice before you give that slim secretary an electric typewriter; she may become a little pudgy if you do.”

How medieval, you say. Yes, but think what a little jewel of mythmaking we have here. The point the scientific types were trying to make was that modern conveniences collectively increased the tendency to overweight — a legitimate but dull observation. The world then took this unpromising material, ladled in the requisite quantities of sexism and BS, and confabulated a story that’s endured for 50 years.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.