When someone says ‘new parents’ the first thing you think is ‘chronic tiredness’ because that’s the image we have of newborn babies – noisy, smelly sleep deprivers. Indeed, we hear mainly about the emotional and psychological effects of fatigue, and that’s not wrong because after eighty-nine consecutive nights of broken sleep I can only ascribe the mistakes I’ve been making recently to the fact I’m shattered – yesterday I put the butter in the cupboard and marmite in the fridge, spent five minutes using fingernails, keys and a penknife to pry the lid off my thermos cup only to discover it’s a screw top, and this afternoon somehow dropped my phone in a mug of coffee.

But I’ve realised of late that there’s a physical toll to parenting over and above simple exhaustion.

We all know that for women there are stretch marks and stitches to contend with (along with hormonal changes that cause them to grow scales and breathe fire, but the less said about these the better). But after twelve weeks of looking after a baby, it doesn’t matter if you’re male or female: the only thing holding your body together is sticky tape and determination. And perhaps a little each of caffeine and codeine.

I have white hairs in my beard. Not grey – white. They definitely weren’t there twelve weeks ago. I’m missing a stage and jumping straight to silver! And my face seems to have lost some of its buoyancy – it’s not bouncing back with boyish elasticity after sleepless nights like it used to. I look tired.

As for Lizzie, I’ve noticed far more grey hairs hiding amongst her dark locks, but more than that, her face has changed in some indiscernible way. I’m assuming it has something to do with gaining pregnancy weight, losing it quickly after the birth, and screwing up her face muscles for nineteen hours of labour until she can crush walnuts with her cheeks. The distances between her features all seem a little off – her mouth perhaps a couple of millimetres wider, her chin a trifle thinner – so that when I lean it to kiss her, or watch her sleeping on the pillow beside me, at times she doesn’t look like Lizzie at all but a stranger in my bed. Some might find that rather exciting – I find it a little unsettling. Nobody prepared me for the fact my partner’s face might change!

Psychological symptoms are having a major impact on my physical health. I look like I’m calm and completely in control, but inside I’m constantly fretting, and so I keep getting outbreaks of psoriasis under my beard – horrible, itchy, sore, red, flaky dandruff-type stuff that I’ve never had before but is driving me mad these days. I rub the baby’s nappy cream into my beard and leave it there, white and gloopy and sweet-smelling, because it cools the irritation. And having Irritable Bowel Syndrome, I’m a nervous pooper, and my nerves have irritated my bowels something chronic – I’ve had diarrhoea five days out of seven since Izzie was born. Everything I eat comes out within a couple of hours – I can’t imagine it stays in my stomach long enough to be digested.

But it does. I know this because I’ve put on a stone in weight since the birth. That’s just over a pound a week. I know the reason. Normally we eat three meals a day because we’re asleep for eight hours, but when you have a baby and you’re awake on and off throughout the 24-hour period, you realise just how gosh-darned hungry you are at three in the morning. So sneaking a fourth meal into your nightly schedule with a bowl of cereal, couple of slices of toast, or bar of chocolate at silly o’clock, really isn’t as beneficial as you might think.

I had my asthma check the other day. My peak flow is the worst it’s been for years. Admittedly, that might have something to do with the fact I’ve been neglecting to take my inhaler, but I’m not above using the baby as an excuse.

When I struggled up from my chair a few days ago, Lizzie laughed and told me I was like an old man. She’s not wrong. Given the pain in my back, shoulders and legs, I’m hobbling around like an octogenarian. My body is wrecked (I have to be careful how I say that, because I told a woman the other day that I was wrecked and realised it sounded like in answer to the question, ‘How are you?’ I replied, ‘I’m erect.’).

Part of the reason is that I sit sideways in the armchair, my back against one arm and my legs hanging over the other so that my knees are level with my shoulders. It makes it so much easier with the baby to support her against my thighs while I’m feeding her or massaging her belly or making bicycles with her legs. It just means I’m scrunched up in a position not very conducive to my own comfort.

In particular, the lower left side of my back is starting to kill me. Being right-handed, I tend to support Izzie with my left arm so I can use the other to hold the bottle, poke her in the nose, ward off the attentions of the dog, or else scratch whatever happens to itch. When I carry her in the sling, I similarly favour the left, with the straps running from my left shoulder to right hip. This means I’m always leaning slightly to the right in order to compensate, straining my muscles as they battle to keep my spine straight.

At least, I hope that’s what it is. The past five days, the pain has moved from the surface to the inside and I can feel it if I press on my front or my back, as though it’s sitting in my kidneys. Worse, it’s spread to my right side in the past couple of days, making me wonder if I’m dehydrated and my kidneys are aching.

And my left arm hurts too. Since Izzie is twelve weeks old, has been bottle fed for ten weeks, had ten bottles each day in the early weeks and around six now, if we average eight per day then she’s been fed in the region of (clasps his tongue between his lips as he tries to calculate it) 560 bottles. If we conservatively reckon I’ve done half of those, then I’ve held Izzie in my left arm 280 times in ten weeks. This might explain why it feels like my left biceps is torn in two, and is far bigger and harder than my right. If I keep this up I’ll have an Arnold Schwarzenegger leftie and a right modelled on Daniel Radcliffe – not attractive but great for hustling an arm wrestler.

So that is the reality of parenting – it turns you into a grey-haired, odd-faced, flaky-skinned, sore-spined, kidney-aching, stiff, limping, fat, lopsided Quasimodo with diarrhoea. We don’t mention that to prospective parents!