According to Jenni Russell, my colleague at the Times, David Cameron has lost 13lb since Christmas, mainly by giving up on peanuts and biscuits. Now that’s a lot of peanuts and biscuits. It’s a bit yo-yo, Cameron’s weight, isn’t it? He gets bigger, he gets smaller again, like a giant, very pink, human-shaped balloon that some giant unseen hand is alternately squeezing and relaxing around the legs. He wears it well, though. When Nigel Lawson lost all that weight he looked like a man with a puncture.

George Osborne only shrinks these days, and will soon be as slim as his own lapels. So I suppose Cameron might be spurred on by the sight of him every morning, picking up muffins in cabinet and putting them down again with a sigh. Ed Miliband is fairly slim, too, although I doubt that’s wholly deliberate. He strikes me as one of those people who genuinely forgets to eat. Indeed, you sort of suspect he might occasionally need a small prompt with the breathing thing, too. ‘Ed!’ Justine will say, in alarm. ‘Your face is doing that purple thing again! And you’re swaying!’ And Ed will gasp, ‘Whoops.’

Pretty much every man I know who is under the age of 55 is on some sort of a diet. This could just be something I’m suddenly noticing because of my own age, which is not quite yet into the foothills of middle age, but has lately undeniably joined the uphill trek out of youth’s hedonistic valley. Only I don’t quite think that’s all it can be. A generation ago, I’m sure men didn’t have figures. Instead they had tailoring. You didn’t have to sculpt your body because that was the responsibility of some oldish, fruity gent with a measuring tape around his neck, who would normally rely upon a waistcoat to do the job. And sure, when said waistcoat was released, a chap might unload like so much blancmange, but how often was this likely to happen? I’ve seen a photo of my grand-father wearing a three-piece suit on a beach. Hot, probably. But dignified.

At any rate, a man could expand back then and nobody cared. You can’t imagine Winston Churchill skimping on the pies. Whereas today, Barack Obama may be the thinnest man in America. Our whole perception of fat has changed. It has become a sort of moral incontinence.

My own diet is sporadic because I am, indeed, morally incontinent. Although in the past six months I have become a gym person. I could pretend that I do this for health reasons, but that would be a lie. It’s all vanity. Which I disapprove of, obviously. On a beach, in a park, I see those men who are buff, lithe and sinewy, and I have nothing but sneering disdain for their joyless, hollow, self-congratulatory existences. The thing is, I’d rather be sneeringly disdaining them without looking like a haggis on legs myself, if it’s all the same to you. Thus the gym.

It’s pretty crowded, my gym. Largely men in their late thirties, and often with quite fascinating bodies. By which I do not mean good bodies. The most common oddity is those men who lift weights all day but do nothing else, and thus have giant, defined he-man biceps, but bellies like a Vietnamese pig and legs like a child with polio. It’s a strong look. And yet on they grunt and sweat, driven by demons that will not let them rest until they are somebody else.

There’s a strong temptation to blame the gays for this, and the way they all suddenly look like they’re wearing those fancy dress superhero costumes with the muscles on them, thus rendering traditional homophobia really hard work.

Or we could blame the media. Recall the fuss 20 years ago when Colin Firth came out of a lake in a wet shirt in Pride and Prejudice. Next to Aidan Turner in Poldark today, he looks like the ‘before’ shot in a diet pills advertisement.

The people truly responsible, I think, are women. Feminists especially. For 50 years now, they’ve been reasonably reminding men to stop staring, while slyly and simultaneously getting ever more hot. And as a result, being simply incapable of doing the mental gymnastics required to stop objectifying women in the manner we have learned we ought, straight men have started trying to make up for it by objectifying themselves just as much. Even if they are the Prime Minister. At least, some weeks.

Mugged by Labour

The Labour party has put its five core election pledges on mugs. No, I don’t know why. Presumably the idea is that you buy all five, and then when your friends come around for tea, you each drink yours out of the one featuring your favourite. Yeah, I know. As if the sort of people who’d buy these mugs would have friends.

There’s an odd fuss, though, about mug four, which says controls on immigration on it. Quite widely, this has been perceived as a gaffe, a betrayal, a slump into Farageism and all the rest, with numerous Labour pundits wailing in dismay.

Why, though? How many people out there don’t think there should be controls on immigration? I’m pro-immigration in almost every scenario, and even I think there should be controls on immigration. Normally, when people say ‘You can’t talk about immigration’ they’re quite wrong. Not here, though. ‘This shameful mug is an embarrassment,’ tweeted Diane Abbott. Indeed you are.