It’s an indictment of our society that a quarter of its adults are clinically obese. The NHS predicts that scale will tip over 50 per cent by 2050. We’re moving to a world where you’re in the minority if you don’t have gravy for blood.

It’s a trend echoed in our clothing. For all the complaints that designers don’t make clothes for ‘real people’, the truth is that our girth is reflected on rails. Since the 1970s, high street sizes have had a four-inch growth spurt, according to research from The Economist. Your ‘M’ trousers are now anything but. This so-called vanity sizing should arrest any smugness about fitting the same waist you did a decade ago.

It’s a fat man’s world. So when you do decide to finally get your body in order, the toughest ask can be finding something to cover it. Your big arms and narrow waist make you an anomaly, and the opposite of what most clothes brands actually cater for. Which is why finding something that fits all over can be tougher than stairs after leg day. Here’s how to ease the pain.

Find Your New Size

Think your gym membership is expensive? Try replacing your entire wardrobe. Whether you’ve gained a chest or lost a belly, what fit before, now probably doesn’t. At least not everywhere. You can’t just step up or down a size; your new go-to is defined by your body’s biggest point. A medium gut but XL arms mean you risk hulking through your sleeves if you step down a hangar.

Look instead for brands with more generous, or athletic cuts. This season E. Tautz pushed a roomy silhouette with low armholes, which means shirts that fit your waist and your biceps. On the high street, Thomas Pink’s athletic line is cut trim through the torso but wider at the shoulders, so your shirts won’t billow around your waist like a sail. And J.Crew’s Crosby line – spanning shirts and tailoring – with its tapered waist and extra room across the chest and arms, is for the guy who knows precisely where the beach is.

(Related: The muscular man’s shopping guide)

Thomas pink Addinsell Plain Athletic Fit Button Cuff Shirt - Click to buy j.crew CROSBY SUIT JACKET IN ITALIAN WOOL - Click to buy e.tautz SPORTS SHIRT - Click to buy j.crew CROSBY SHIRT IN END-ON-END IRISH COTTON-LINEN - Click to buy

But Leave Some Room For The Imagination

Your birthday suit should be skintight. Your actual suit, less so. “It’s better to have clothing that fits, and shows off your physique in a subtle way,” says Erika Nilsson-Humphrey, founder of personalised stylist service Dappad.

Your body shape may have changed, but the rules of tailoring stay the same. “The seams should rest at the edge of your shoulders, the jacket should cover your buttocks and when the button is closed, you shouldn’t see any X-shaped stretching.”

J.Crew Crosby Suit

Learn Some New Style Moves

Your new physique opens the door to a glut of pieces your former body could never pull off. And no, we do not mean vests.

Take the Henley shirt, a favourite of notable torso-flaunter Ryan Gosling, who takes every opportunity to prove why a figure-hugging fit and buttoned neck – pop a couple if you’re feeling warm after chest day – play so well with your new training regime.

Key Pieces

NUDIE JEANS Fairtrade Organic Cotton-Jersey Henley T-Shirt - Click to buy river island Navy chunky ribbed muscle fit henley top - Click to buy SCHIESSER KARL-HEINZ SHORT SLEEVE HENLEY - Click to buy mango man Soft egyptian-cotton t-shirt - Click to buy

Make Friends With Your Tailor

When your body breaks the mould, you break designers’ moulds too. It’s a truism that nothing fits you perfectly off the rail. But while you can live with a little hugging round your hips, when your jeans won’t pull over your thighs, you need to call in support.

A decent tailor can do just about anything, from nipping in your waistband, to finding space for those new glutes. Up top, if the shoulders and upper arms fit – that means no pulling fabric round your biceps or along your deltoids – then he can bring everything from cuffs to hem into line.

While you’re there, get him to shorten your T-shirt sleeves to halfway along your triceps, to accentuate your arms without forcing anyone to the gun show.

(Related: 9 ways a tailor can make you look better)

Don’t Dress For The Body You Want

Willpower is a fickle beast. But filling your wardrobe with clothes that don’t fit – yet – is no way to tame it.

“It’s a faulty approach to buy smaller clothes because you want to lose weight,” says Nilsson-Humphrey. If you’re convinced you’ll make the change, save money now to buy better clothes later, since you don’t know what will fit until you actually build that body.

Set small, achievable goals and put £10 aside every time you hit them. Seeing cash stack up for each kilo you lose inspires you to keep going.