Seven smug dieters to avoid this month.

Do you think the Romans – you know, those guys who wore bedsheets and invented the word “January” – spent the first 31 days of the year saying, “No thanks, just water for me,” and “Do you have a gluten-free menu?” No, of course they didn’t. They were far too occupied with politics, killing things and working out whether they should be using the indicative or subjunctive mood to say, “Wowee… Wow… I’m drunk, guys… Seriously…”. By the end of the month, they weren’t slimmer, healthier and more alert than ever. They were all slumped over each other in a giant, drooling and orgiastic heap, like a pile of particularly dirty laundry that no one can be bothered to stuff in the machine.

How then, did we get to the current state of affairs, where January is the time that you try and sort out every problem in your life, all at once, however self-defeating and depressing that process might turn out to be? Of course, the difference between 700BC and 2018 is that now we’re living in an era where self-improvement is not just a trend, but a multi-million-dollar industry, and the month of January is essentially the second, more punitive chapter in the consumer hysteria of the holiday period. As the glassy-eyed, rictus-grin wellness machine springs into gear in early 2018, it seems that Dry January, which has only been a thing since about 2014, was just a starting point for this annual festival of self-abnegation.

These days, nothing less than a complete lifestyle revamp, wardrobe clearout, Instagram detox diary and revised, 24-point life plan will do. Which is why you’ll spend much of the next few weeks listening (and watching) as people reel off long, smug explanations (online and in person) of the self-imposed, horrible eating regime they’re following, despite the fact there’s not a chance in hell they’ll still be doing it by Valentine’s Day. Appealing as that all sounds – we can hardly wait – we thought we’d save you some time by describing the common varieties of gastronomic penance. In short, you’ll be able to take the words right out of their mouth, which, seeing as they’re basically refusing to eat anything, will hopefully leave them nothing to do with that particular orifice but shut it.

Did you know that if you cut the amount of food you eat by nearly a third you lose weight? It’s astonishing, but true. It’s also common sense. But who cares? In the early 2010s this pearl of wisdom was repackaged as the 5:2 diet, in which you starve yourself for two days a week and fecklessly indulge your most base impulses for the rest of the time. Adherents of this particular discipline used to be called binge drinkers, but now they’re considered among the most switched-on of today’s health and fitness adepts. Basically this is not just a diet, but an excellent PR campaign for people who love pizzas and pints.

As your personal trainer will gladly tell you at length (seeing as he’s being paid by the hour), the key to muscle growth and fat loss is cutting out carbs and upping your protein intake. It’s a diet that has attracted a number of celebrated adherents, from Messrs Chris Hemsworth and Zac Efron, to the giant, man-eating shark from Jaws. What nobody tells you as you embark on this particular eating plan, and what you realise about 300 grilled chicken breasts down the line, is that guzzling back the remains of as many dead creatures as possible (washed down with a shake that tastes like powderised mummies) tends to leave you not just buff, but constipated, and the remedy – to throw in a bucket of lentils now and again – can have rather explosive side-effects. Which leaves this particular dieter in a somewhat tricky situation. Everyone likes looking at his gym selfies on Instagram, but no one wants to stand next to him in the lift.

Detoxing has been debunked many times by experts and journalists in the national press. But many people still seem delighted to delude themselves into thinking that living on juice for a month, or boiled water and cayenne pepper, or large quantities of indigestible silt, will somehow, over the course of many weeks, do them some good, beyond ridding them of excess hair, teeth and the will to live. You’ll recognise someone who is on a serious detox thanks to their almost transparent complexion, their world-weary smile and a pair of watery, wolfish eyes that are constantly fixed on the clock, counting the minutes until their next, generous, two-calorie fix of mushroom and maca water or spirulina mist. Doctors sometimes call this state of affairs malnutrition. But, pshaw, what do they know?

Millions of years ago, human beings ate much, much better. Not at all swayed by the gawdy advertisements painted on the cave walls, they eschewed chocolate and Pot Noodles and instead opted for raw cacao and macadamia brownies, breadless cucumber subs, mushroom courgetti bolognese and other such delights, spiralising squash over a roaring open fire, foraging for pure, unrefined ingredients to bring back and blitz in the Stone Age NutriBullet. This, it seems, anyway, is the thinking behind the paleo diet, a popular eating plan that aims to get us back to the only way of eating that, evolutionarily speaking, makes any sense at all. Granted, prehistoric man didn’t have a nine-to-five, so was able to spend two to three hours a day preparing little stony boxes of carbless, sugarless, funless nourishment to slug around with him all day (because even then, restaurants couldn’t quite grasp the whole thing), but you can free up some time too, right? What’s a social life compared to knowing that you are nailing what is quite literally the most outdated diet ever?

It’s long been argued that the process of industrialised meat and dairy farming is utterly cruel and unsustainable in a world crawling with seven billion people, that it’s every human being’s responsibility to their own species to eat less of such produce, if not to give it up entirely for their health. But no one really cares about that. On the other hand, there’s this Netflix film Okja and it has a very cute, giant CGI pig in it. If you haven’t seen it, you should. Really, it’s heartwarming. And what more reason could you need to suddenly, without warning go vegan, much to the chagrin of all those who have been doing it for years? There are many benefits to veganism. No, we’re not talking about all that boring environmental stuff. We’re talking about the fact that every time you sit down to dinner, you get to talk about yourself – what you will and won’t eat, how you’ve coped without cheese, why actually it’s not that hard at all if you’re as clever as you are – for at least 10 minutes, if not more. Yes, OK, you might get drunk now and then and scoff back the odd Scotch egg, but you’re new to this. And isn’t the most important thing about veganism spreading the message. Isn’t it?

Can you believe, in this day and age, that some people actually see food as something of a pleasure rather than an inconvenience? It’s almost as if they don’t have anything to do. But there’s so much to do, isn’t there? How and why would you want to waste time on a square meal when you’ve got 25 startups to launch, multiple self-help books to write, when you’ve got both a Twitter and Medium profile to constantly update? Who are these people who have the patience and, more importantly, bandwidth to preheat ovens, boil water, to actually stick a fork in something, raise it to their mouth and shove it down the hatch? So laborious. Thank goodness, then, for the invention of meal-replacement powders – everything you need to stay alive (and nothing more, thank you) in a resealable packet with a lovely Helvetica logo on the front. You can free up your schedule (and, thank goodness, stop those taste buds working so hard) by ingesting one spoonful of the wonder dust three times a day, eliminating the need for those pesky mealtimes completely. Everyone will be impressed and awed by your dedication to performance and productivity. Come lunch hour, they’ll all be out at Five Guys without you but, we promise you, they’ll be the jealous ones.

Diets are like trends. Not only do they come and go, they’re passed on via peer pressure. Which means that, even though you might trick yourself into thinking you’ve embarked upon a particular regime for some kind of health benefit, the likelihood is you saw someone doing it on Instagram, or read about it in a magazine, or are just doing it because your other half is and it makes the weekly shopping easier. Which leads us to a troubling question: why are some people still doing Atkins? The experts have debunked it, but that kind of thing is never usually much of a problem in the dieting world. The bigger problem is no one thinks it’s cool any more. They’ve all moved on to Whole30 instead. So you, with your little jar of peanut butter and Ziploc bag of bacon, what are you doing? No one thinks it’s big. No one thinks it’s clever. The restaurants have deserted you. Social media doesn’t want to know. How terribly, terribly sad. In short, if there’s one thing you need to remember about fad dieting it’s this: at least make sure your diet is actually still a fad.