A fast before the feast: why you should turn down the treats till Christmas

This is however an unfortunate coincidence, as Christmas is also documented aggressively. From parties to festive walks to wintry pub sessions, pictures of your ruddy face will be popping up everywhere; indeed, anyone particularly invested in your social footprint will be able to observe the widening of your gut almost in real time. Even Cara Delevingne (Model of the Year) has been accused of succumbing to festive bloat: model Robert Konjic whispered that he wasn’t surprised that Cara didn’t make it into this year’s Victoria’s Secret Show. “I bumped into her at the British Fashion Awards and she looked very bloated,” he said (very) cattily.

Moreover, Christmas is prime pulling season (those Love Actually repeats really hammer home the loneliness of singledom) — and no one wants to get off with the Christmas pudding. And thus canny (horny) Londoners have been confounding the usual excess for a pre-Christmas fast — to ensure they look banging for the carousel of parties this week.

Even if you haven’t started yet, arguably, it’s easy enough. You have just nine days until Christmas Eve. Even if you start restrictions now you have just enough time for an aggressive 5:2 (tip: deprive yourself on “normal” days too) or adopt a gimmicky diet that will help you laugh off the allegations of joyless obsession.

For example, there’s the Holy Diet, which, depending on the denomination to which you attach yourself for the purpose of weight loss, can include fasting, consuming only crumbs of loaves and fishes, or filling up on meditation; un-PC revellers will find your heretic regime hilarious and thus won’t push the mince pies. Others go on an aggressive juice diet to prepare for a fancy Christmas do, or adopt a “canapés and vodka-tonics” diet (fast all day; feast all eve), which means they don’t have to stay housebound every evening.

Gyms are bewilderingly packed: when I visited Virgin Active one evening last week, I had to hang around like a Lycra lemon holding a single free weight for about 20 minutes until there was space to use it; treadmills and crosstrainers were also commandeered. Advent Running (adventrunning.com) is a short-term programme: the idea is to do at least 30 minutes of running every day till Christmas.

Meanwhile, yoga instructor Kelly Isaac just finished her 80th class in a row, a continuation of a 30-day challenge she started in October, and recommends staying healthy during the winter months.

“At the end of October I felt so energised and on top form that I decided to stick to it,” she says. “There is no cure better to wipe away the morning after the night before than sweating the toxins out, and your confidence levels get a great boost when people comment on how well you’re looking.”

Essentially, it’s short-term pain for short-term gain — but you will look svelte for that festive date (remember, the buffer you are, the more likely the mistletoe snogs and wintry walks of shame). Plus, cutting back on treats now means you’ll minimise the guilt you feel bingeing wildly on Christmas Day: feasting is more fun if you feel like you really earned it. Promise.

Try telling everyone in the office about your fast so that you have people to hold you accountable. And when someone inevitably tries to sabotage you by wafting a choccie Advent calendar under your snout, you can turn it into a stubborn exercise in passive-aggression — a potent fuel for your willpower. Alternatively, every time someone offers you a mince pie, stub your own toe — another exercise in Pavlovian conditioning. If you lack self-control, drop your food onto a germy floor and hope it picks up enough to put you off. Hang out with people who feel a bit pukey: norovirus is basically a way to drop five pounds in two days.

Just remember to stay hydrated to avoid a pre-Christmas trip to A&E. Don’t make a meal of things; what deprivation lacks in festive spirit it more than makes up for in smugness.