When Séamas O’Reilly embarked on a mission to change himself from ‘slob’ to ‘fitter slob’, he was hoping to lose some fat and find some muscle. But he ended up transforming himself in more ways than he could have guessed

Sarah Lindsay recites numbers as she pinches my folds. She does this under her breath, the way a dentist uses that odd numerical language to gossip about your molars right in front of you. “Chin 11.8, Mid aux 22, Supra 45.” I shudder from the touch of cold callipers on my skin as this last measurement is taken from my suprailiac area. Closer acquaintances would, I suppose, call them my love handles, but Sarah is good enough to keep things mildly formal, perhaps to offset the fact that she is measuring the fat on my body just a few minutes into our first meeting. I am standing in her office at Roar Fitness, and my initial consultation is under way. It is Day 0 of my physical transformation plan and, following a brief chat, my top is off and it’s straight to the skin folds. This term itself is not ideal. Skin folds. It’s standard anatomical parlance, but it conjures images of oversized wildlife – hippos hoist into the air so the zoo can wash their meaty shanks. I am, of course, making these connections because I am staring in the mirror as all this is being done and noticing, perhaps for the first time, how much my body has changed in the past couple of years.

Harry Hill says he knew he was going bald when it started taking longer and longer to wash his face. I first noticed I was gaining weight when I started having to reach a little further to wash my sides in the shower. That and realising, around the time my son was six months old, that his adorable little pot belly and my own seemed to bear a family resemblance. If I’m being honest, my body’s journey from lad bod to dad bod preceded fatherhood. I spent my youth as that skinny, lanky child who never put on any weight. But with advancing age came lower metabolism, and a move away from retail and minimum wage jobs that kept me on my feet all day, to more settled and sedentary creative pursuits that see me now, aged 34, heartier than I once was.

This isn’t a remarkable story, I grant you. Mine is the experience of millions of people my age, and a minor version of the process compared to millions more. The UK is in the middle of an obesity crisis: over 60% of the population is overweight and roughly a third of UK adults are obese. Figures for children are equally shocking.

So, no, the love handles you see on these pages, squishy as they are, don’t constitute a grand horror story, nor are they anything to be ashamed of. I was mostly healthy and, overall, happy with myself, but I also felt a little slower to move and lift and spring to attention, and chasing a toddler around had put these changes in stark relief. I also have a family history of diabetes and bowel disorders, and wondered if I could make the changes necessary to offset later risks.

Facebook Twitter Pinterest Pinch an inch (or more): Sarah Lindsay gives Seamas a skin fold test at the start of his session. Photograph: Pål Hansen/The Observer

And, I’d noticed, the tools to offset those risks seemed to be everywhere. It’s a curious quirk of our current age that, as we grow ever more lightbulb-shaped, a head-spinning profusion of diets, fitness regimens, self-health books and body-shaping plans has exploded. Physical transformation has, in theory, never been more accessible to those of us who find themselves the unexpected proprietor of a nascent dad bod, and theres’s no shortage of social pressures for us to avail of them.

It should be said that some of this focus on health doesn’t seem particularly healthy. Short-term body projects are complicated, controversial things. Doctors don’t tend to recommend them, for fear of the mental and physical damage sparked when a desired physical form is unrealised. The ideal male physique is now everywhere around us, from the pneumatic tightness of Love Island contestants, to the preened and perfect bods of Instagram fitness gurus selling us diet teas, gamified fitness trackers and wellness apps. It is a taunt, unattainable and unsustainable – a 12-week course at Roar costs more than £3,000. In agreeing to write this article, I kept telling people I was looking forward to doing the mildly silly Before and After shots, precisely because I find the “black-and-white-sad-man versus full-colour-beefcake” contrast so ridiculous. As a congenitally cynical person, I was incredulous as to how real or positive those images were. But, if I’m honest, some of that curiosity was borne of having passed those images a thousand times, patting my belly, and wondering if I could achieve similar results.

At Roar, I embarked on a fitness and diet plan aimed at getting me from dad bod to rad bod in just seven weeks. (They would have had me do it longer, but since we were starting at Halloween, a suitably festive Halloween-to-Christmas arc was agreed, in the hopes that my reaction to my workouts would likewise turn from horror and darkness to joy and good tidings.) Now, finished with my folds, Sarah is quick to point out the difficulty of my task. “No one does this in seven weeks,” she says, “so we’re really going to have to push you.” I feel a pit somewhere in my stomach open. I’m fairly sure that what she terms “pushing” I am likely to consider borderline inhuman. Sarah is a three-time Olympian and nine-time British speed-skating champion, who runs Roar Fitness with her partner, Rich Phillipps. They specialise in physical overhauls. The walls of their site near Moorgate are decked with Before and After shots that show dramatic – sometimes scarcely believable – changes in short spaces of time. None, however, as short as seven weeks. “These are 12 weeks, 16 weeks,” she says, pointing at the grid of achievements. Some depict programmes spanning half a year.

Seven weeks means a radical dismantling of my diet, excluding all booze, dairy and oils, and a near total ban on carbs, fat and sugar – even fruit. All this before I begin my exercise routine, which starts each day with a 40-minute pre-breakfast run, followed, three times a week, by a weights session with a personal trainer. When my full plan arrives in my inbox on Halloween night, I shoo my loved ones off to enjoy their trick or treating and ponder what exactly I’ve let myself in for.

Facebook Twitter Pinterest Powering through: hitting the weights with personal trainer Alex. Photograph: Pål Hansen/The Observer

Within the diet’s first few days the answer to that question is clear. My breakfast of salmon and eggs with green veg isn’t, in and of itself, particularly onerous. Nor the chicken and veg for lunch or the white fish with veg for dinner. They are all, with certain tweaks, meals I could imagine enjoying in any other context. But that context would almost certainly involve butter, oil, cream and, I soon realise, the numerous extra little treats I clearly wasn’t tabulating in my assessment of my moderately healthy, but gloriously unrestricted, diet.

Worse is the lack of variety, since my diet prescribes those exact same three meals every single day with no variation, save a daily allowance of 21 olives – not 20 or 22 – and a protein shake to be taken after every workout.

The workout is a crash course in upper-body exercises with Alex, my trainer. “So,” he says on Day 1, “will this be your first workout?” I don’t know if he means my first workout for this project, or my first workout ever. I say “yes”, because it’s true of both questions. I have never used exercise equipment in my life, never lifted a weight or troubled the pedals of a stationary bike.

Alex is patient and kind as he introduces the machines, taking great care to describe them to me in the way I talk to my dad about internet memes – slowly, while leaving judicious gaps for the many, many questions that will arise.

Woody Allen famously described Arnold Schwarzenegger as having “muscles in places where I don’t even have places”. I thought of this quote often as these sessions began forcing unfamiliar patches of meat into action. Suddenly I was aware of “places” in my body that didn’t exist before, pains I couldn’t even readily identify. It was like growing six invisible new foreheads all over my body, and getting a zesty little migraine in each. I began to realise that my frame had been carrying a lot of passengers, muscles that had sat in the background of my body like those slightly less prominent members of So Solid Crew. Now they jolted into life, shrivelled and screaming in the darkness of my arms, shoulders and back, roaring to let them return to 30 years of unbroken sleep. Alex had other ideas, however, and quickly set about reducing me to a sweaty nub of offal each Monday, Wednesday and Friday, until that constant, heady state of alarm dulled to a dim resentment and, even, something like satisfaction from their first honest days’ work in my lifetime.

Facebook Twitter Pinterest ‘I began to feel better about myself in a way that transcended looking good in photos.’ Photograph: Pål Hansen/The Observer

I saw some drastic improvements quite early, dropping nearly a stone in the first two weeks. A large part of this, I reckoned, was the absence of booze. I didn’t think of myself as a heavy drinker, but now had to realise I was treating a nightly glass or two of wine as not just commonplace, but common sense. It had become my accompaniment to every dinner, and a reward for each tiring, overspent day. Within four weeks, I realised my morning runs were not just more manageable, but – and I am disturbed to even write this – enjoyable.

When tracking my progress in those first few weeks, friends often asked if I felt different, and I found it hard to answer. I mean I guess I did, but the exact manner of this difference was hard to quantify. I did feel stronger, but I was also usually slightly sore from working out for the first time in my life. I was running faster and for longer, but was also more fatigued between runs as I was having fewer rest days. Not drinking had probably left me more clear-headed in the mornings, but I’ve never suffered overly from hangovers so it was hard to really know how much better I felt when they went away entirely.

Moreover, any sense of wellbeing these improvements should have engendered was tainted by my reflexive tendency for self-pity, since I spent the first few weeks extraordinarily resentful of the diet. Had I been on a longer course, say 12 or 16 weeks, it wouldn’t have been so severe, but I started to realise just how much of my life was mapped around mealtimes, how much excitement I take from food – cooking and eating and hosting, all of which was now denied me.

For the record, I’m delighted that I take so much joy in food and, for all I might amend my more extreme acts of gluttony, or portion sizes, this experience means I will never again take that joy for granted. To my amazement, however, I grew to enjoy the various seasonings and spices I could use on my same three meals, and stopped missing my nightly wines within the first week or two. The same could not be said for other, less expected, abstinences. I found myself daydreaming about the rich, warm waft of butter on toast, the first creamy mouthful of a buttered spud and the quotidian ecstasy of an honest-to-goodness cup of tea. Teas were, incidentally, included in my approved list, but milk was off the menu, and I’m sorry but black tea is horrible.

By the fourth and fifth week, I found my appetite had changed sufficiently that I no longer looked at my diet in horror, but as a job to be done. As much as I looked forward to all the old joys that eating offers, I was surprised, and pleased, by a newfound ability to maintain discipline, if only for the novelty of it. Stranger still, I was now relishing my workouts, as the weights I was moving doubled in quick time. I looked forward to my time with Alex, and the belief he had in my ability to push further and further each day.

Perhaps most surprisingly of all, I was beginning to admit how much I enjoyed the physical changes to my body. I was thinner, yes, but I was also stronger and felt, undeniably, better about myself in a manner that transcended simply looking better in photos or fitting in old clothes again. “You see people change through the process so much,” Sarah says when I mention this. “Especially when it comes to getting strong. People come, a lot of the time, to lose weight, but when they start to get stronger, it’s really empowering.”

Sarah has an open, easy manner and the unfaked enthusiasm of one of those cool young teachers you end up wanting to impress. I realise, to my shame, that before I’d started this thing I’d been worried – actually, dimly terrified – about how all these fit, beautiful people would regard my shlubby frame and wobbly bits. By the end of my seven weeks, I’d been disarmed by their patience and empathy and their understanding of how transforming the physical affects the psychological. “Honestly,” she tells me, “it’s more than half the job. People do this because a lot of the time they don’t feel good. Maybe eight out of 10 people cry in their initial consultation, because they end up saying out loud for the first time that they’re not happy.”

Facebook Twitter Pinterest Before and after: ‘With seven weeks to play with, I was never going to end up a bodybuilder, but I’d attained a leanness I hadn’t considered possible.’ Photograph: Roar fitness

I realise I’d spent my life carrying around certain self-serving fictions about health and fitness that this modicum of effort had challenged. I’d internalised the idea that dwelling on the physical was for other people or, worse, symptomatic of society’s wider problems with fat-shaming or obsessing over appearance. Seeking fitness was admirable, of course, even tracking it was desirable in a nerdy sort of way. But flaunting it, or enjoying your physical appearance for its own sake, was gauche or vain.

At the end of the regime, I had changed, but so had my preconceptions about the process itself. With seven weeks to play with, I was never going to end up a bodybuilder, but I’d attained a leanness I hadn’t considered possible, remapped the frontiers of my own endurance, and shed 2st. But I was mostly delighted with smaller improvements I’d made along the way – lifting more, running harder. I was running 5km in 22 minutes, having started at closer to 30, but was prouder still that I no longer needed to pause for breath when picking up my son. I’d expected to shift a bit of flab and generate enough content to make a gently self-deprecating article that charted my unlikely transition from slob to slightly-fitter slob. It is with a mixture of horror and delight I can report that this transformation was more, well, transformative than that.

Roar Fitness is one of the UK’s leading personal training gyms (roar-fitness.com)