Crying gym
I feel this girl's pain Getty

We're only two weeks into 2015 and January already feels like punishment for having fun. December is Christmas so you can eat what you want – if standing at the counter trying to wedge an entire cheeseboard into your face makes you happy, then go for it.

You've got the Boxing Day sales, so if your thoughtful, lovingly wrapped gifts just didn't satiate your appetite for stuff, you can at least paw through a pile of sequinned leftovers at a knockoff price. New Years' Eve is fun provided you don't work behind the bar, and the next day you'll laugh with gusto about how you lost all your friends and sat in a park with a stray dog for three hours, sharing a bottle of Blossom Hill. Again. Classic.

I had the displeasure of stumbling upon this pile of vacuous, guilt-baiting piffle in the Standard the other day. Lily Rae

It's especially tough for women because now, more than ever, we're told to whip our saggy arse into shape and magically transform from swollen grubs into smart-casual butterflies, but – as the Evening Standard dictates – we now have to look good while we're metamorphosing as well, by buying a load of crap make-up, which is supposedly "exercise-proof".

The number one new year's resolution across the UK appears to be "lose weight". Now, more than any other time of year, it seems like women especially are pitted against each other in a race to recover from having a nice time. The diet industry – worth around £2bn in the UK alone – has proved practically recession-proof because it relies on failure and people feeling bad about themselves.

Diet products that claim to be low in fat are often high in sugar because they'd be too bland to enjoy otherwise. Also, have you seen the portion sizes of these diet meals? They're tiny. You have to eat four Live Well lasagnas just to feel it touch the sides.

And now, as if there wasn't enough puritanical misery in January, there's this "Dryathlon" nonsense. The idea is you spend one month of the year not drinking – dry January, which considering the ludicrous Old Testament rain we've had seems a somewhat ironic title.

By all means, stop drinking for a month – it just means I won't have to look at you – but here's what will happen. You'll return to work to 10,000 emails, half your colleagues still on holiday, the other half frantically trying to get you to do the work they should have done before Christmas, a bank account sitting under a foil blanket with a thousand-yard stare, and the tax man oiling himself up with a nasty grin on his face. At this point, denying yourself the bottle of Tanqueray from your cousin is not virtuous – it's masochistic.

You might decide to quit smoking. You can't really defend smoking. Everyone should quit smoking but are you really going to get through the month without just one to calm your nerves? Maybe you'll take up meditation, though you can't cross your legs because your arse is too fat, so you sit there worrying about everything you promised yourself you wouldn't worry about. Going vegetarian? At least it might ease the constipation resulting from eating several pounds of cheese.

Being happy is more important than being thin

In January, denying yourself the bottle of Tanqueray from your cousin is not virtuous – it's masochistic.

Susie Orbach, splendid woman and author of Fat Is A Feminist Issue, actually proposed taking Weight Watchers to court because of its shameless targeting of female insecurities. Meanwhile Gillian McKeith was ordered by the Advertising Standards Agency to drop the "Dr" from her title because – surprise – she has no medical qualifications whatsoever and was in no position to tell anyone how to diet. The only reason the diet industry exists is because dieting rarely works. You're pushing a snowball of your failures uphill, while Sisyphus looks on, shaking his head, saying "nah mate".

I'm not saying you shouldn't exercise, just that you should do it for the right reasons. Is it fun? Does it make you feel good about yourself? If the answer to either or both of these is no, you need to stop worrying about fitting into a pair of jeans and start finding out what makes you happy. Think This Girl Can, not crash-dieting.

A balanced diet with a variety of vegetables can reduce exposure to cancer. And happiness. REUTERS

New years' resolutions might be good intentions but if your Facebook timeline is anything to go by, it quickly turns into a high-horse race. When your best friend has successfully swapped delicious coffee for disgusting green tea, you don't feel happy for her. You feel competitive.

She went for a run this morning, and your exercise clothes don't even fit you anymore. You hate her. Her mission for improvement is working and yours isn't.

Your competitors post sepia-filtered pictures of coffee with immaculate latte art, a casually positioned book of poetry by Charles Bukowski, and what you can bet is a vegan muffin. Your ex may announce he just got engaged, at which point you experience a choking fit and wet lumps of biscuit fly out of your mouth and spray all over your keyboard.

In that final second between 31 December and 1 January, we seem to think that we'll level up and gain this new dedication to improving ourselves – but, really, we're pretty good the way we are. We could all be healthier, we could all be thriftier, and we should definitely put the leftover mince pies in the bin. But the only real way we're actually going to have a good year is by being happy.

January is designed to make you spend money on hating yourself but there's no point. I went out for dinner with a friend recently (ruining the save-not-spend initiative) and she explained to me that her Paleo diet would start tomorrow, just as soon as she'd finished the naan bread. Then, rolling a cigarette, asked if I wanted to come for a run on Tuesday. It seems the road to hell is paved with resolutions. And gin.