It has popped up in Britain, too. And as its electoral cycle kicked off last week, when Prime Minister David Cameron officially asked the Queen to dissolve Parliament, it was front and center, thanks to an interview Mr. Cameron gave to The Times of London, in which it was revealed that he had lost 13 pounds in three months by renouncing peanuts and cookies and cutting down on carbs.

Image David Cameron. Credit... Ken Mckay/Agence France-Presse — Getty Images

This came after an earlier pledge to lose weight made in January on BBC Radio Sussex, in which the prime minister called his efforts to slim down “a great patriotic struggle.”

And it was followed by praise for Chancellor George Osborne’s previous and significant weight loss, achieved by going on the 5:2 diet (the one made popular by the Jennifers Aniston and Lopez in which you eat what you want for five days, and then effectively fast for two).

As the race to become the next prime minister begins two years of Western electoral cycles, with Canada expected to go to the polls later this year, America about to descend into a 16-month race that began last month with the Ted Cruz declaration, and France gearing up for its 2017 election, the weight card is shaping up — pun intended — into something of a modern strategic tool. At least (and this is particularly interesting) among the men.

In 2012, part of François Hollande’s pre-election makeover involved a public promise to diet (one of his less flattering nicknames was “Flanby”) and a subsequent 15-kilogram (33-pound) weight loss. In 2006, Mike Huckabee, a potential candidate from Arkansas, actually published a diet book, “Quit Digging Your Grave With a Knife and Fork.” Jeb Bush has revealed he follows the Paleo diet. Such history would suggest that where Mr. Cameron has gone this time around, all three may soon follow. (Mr. Huckabee, who has gained a fair amount of girth in the last few years, certainly has opportunity here.)