Perhaps you’ve always enjoyed a gin and tonic after work, or a glass or two of red wine with your evening meal. Half a bottle of ­sauvignon blanc seems a reasonable way to celebrate the end of the working week and what party is complete without a bit of bubbly?

Recently, however, the health concerns surrounding alcohol have become harder to ignore and it might feel like every other person you know is taking a break from booze. But what exactly happens when we abstain for a month? And is it worth it? ‘You can expect more sleep, more energy and less anxiety,’ says ­William Porter, author of the bestseller Alcohol Explained.

Other benefits are less obvious, however, and there can be surprising side-effects too. Here’s what you can expect, day by day.

Day 1: Anger and anxiety abound

You’ve told your friends you’re taking the month off and all ­alcohol – which your liver breaks down at a rate of one unit per hour – has left your body.

You might have hoped to feel ­virtuous and excited but, instead, you’re firing off angry emails and snapping at your spouse.

This is expected, even among moderate drinkers, explains Porter, who stopped drinking ten years ago. ‘Alcohol is a sedative which the brain tries to counter by releasing stimulants such as cortisol and adrenaline.

‘When the sedative effect wears off, the stimulants can leave you with a residual feeling of irritability and anxiety.’

Try to distract yourself with a walk, watching something funny on television or by carrying out a satisfying chore. And remember, the feeling is temporary: ‘By day two it will have significantly reduced and by day three or four it should have gone entirely.’

Day 2: Why can't I sleep?

You’re used to seven hours shut-eye. Now you’re limping through the day with four. What’s going on? ‘If you regularly drink even a couple of glasses of wine a night your brain starts to rely on the sedative effects of alcohol to put you to sleep,’ says Porter.

This gives us the false impression that alcohol is an effective sleep aid, when it’s anything but.

Booze might knock us out but reduces the amount of time we spend in the rapid eye movement (REM) cycle of sleep, which has the most restorative effect on our body. ‘It can feel unnerving at first as your brain tries to put you to sleep naturally,’ says Porter.

Exercise has been found to regulate the circadian rhythm and may help you nod off sooner. ‘There’s not much else you can do, but the situation normally rights itself by the third night.’

Day 5: Attack of the munchies

You’re not imagining it – you really do want to eat KitKats round the clock. With more than 7g of sugar per bottle of white wine, sugar withdrawal symptoms can be strong after quitting booze and in the days after stopping it’s quite normal to crave sweets and chocolate to compensate.

‘Some of my students drink for an energy boost and pick me up as much as anything else, so suddenly losing that sugar hit can leave them feeling a bit flat to begin with,’ says Kate Bee, founder of online sobriety support group The Sober School.

Porter suggests giving yourself ‘free rein’ to indulge for around six days before attempting to eat more mindfully and reminding yourself of how far you’ve come.

‘It takes time for the benefits to accrue and it’s easy to miss them at first. Think about how you feel when you wake without a hangover. Journalling your feelings can help.’

Day 7: Seriously strange dreams

By now, your sleep will hopefully have improved, but you’re likely to be having wacky dreams too. This is because, without alcohol, your brain is spending more time in REM sleep (five or six cycles per night as opposed to one or two when you’re drinking).

This is ‘the crucial part where your brain interprets what’s happened during the day – brain sensors have shown it can light up [even in sleep] as if it were awake,’ says Porter, who adds that for several days you may experience something called REM Rebound, where your body attempts to make up the sleep you lost while drinking. ‘Your dreams may be so vivid they almost feel like hallucinations and this may last a few days, but don’t worry – it’s a sign your brain is healing.’

Day 10: Better mood and plumper skin

Although the alcohol has long since left your body, it can take up to ten days for the chemicals drinking releases, from dopamine to cortisol, to stabilise.

At this point your brain reaches homeostasis (a balance among all body systems needed to function correctly) and – hoorah! – your mood should improve.

‘By the end of the second week, around the ten to 14 day mark, people start to see real improvements,’ says Bee.

‘You’re likely to be better hydrated by now, which should lead to plumper skin,’ adds Porter, who explains that downing a pint of water before bed after an evening drinking alcohol doesn’t really rehydrate you.

‘Alcohol changes our internal mechanism so the body releases excess water – only after the effects of alcohol wear off can we rehydrate.’

Week 2: Your gut improves

Your gut microbiome is likely to be better balanced and you’re likely to see ‘far less overall bloating in the stomach area,’ says Dr Ross Perry, medical director of skin clinic Cosmedics.

Excessive alcohol consumption interferes with how well our body absorbs nutrients and increases the gut bacteria known to trigger inflammation, explains Sonia Khan, gut health expert and senior pharmacist with feelgut.co.uk. ‘A gut imbalance because of excessive alcohol consumption will typically cause symptoms such as bloating, excessive gas, diarrhoea, constipation, heartburn, abdominal pain, tiredness and food intolerances.’

Although you may already have noticed an improvement to symptoms, Khan says ‘gut health will typically take two to three weeks to significantly improve’.

To speed the process, Dr Vikram Murthy, NHS GP and co-founder of the Harley St clinic Murthy Health, suggests drinks containing prebiotics and probiotics and eating fermented foods such as sauerkraut and kimchi.

Weeks 2 to 3: You may still want to sleep

If you’ve been drinking wine every night for years, you may reach the halfway point of your month off the booze and still feel all you want to do is sleep for a fortnight.

This is because ‘there’s a world of difference between alcohol-induced unconsciousness and real sleep,’ says Porter, ‘and after the first three or four days people often start sleeping loads, which makes them feel more tired and they go through a period of tiredness. The longest I’ve known this to go on for is three months but it usually lasts two to three weeks’.

After which, he says, ‘focus is likely to improve’.

Studies show stopping drinking improves memory among even the heaviest drinkers.

A report in the journal Alcohol Health And Research World found that two to three weeks after alcoholics stop drinking ‘they show considerable recovery in most verbal processing cognitive functions; these areas may even return to normal functioning levels’.

Week 3: Lower blood pressure benefits

Alcohol causes blood vessels to constrict, making the heart work harder, raising blood pressure. But, says Dr Perry, ‘after three weeks blood pressure will reduce’. This not only lowers the risk of strokes and other cardiovascular problems but can dramatically improve energy levels.

‘Your body tries to counter a high heart rate and blood pressure by making you rest, which is one reason drinkers feel lethargic,’ says Porter.

‘Once you stop you’ll have more energy and by week three exercise will feel easier.’

Lower blood pressure will also reduce unflattering red skin caused by burst capillaries, says Porter, ‘and eyes will look less bloodshot – there are very fine capillaries in eyes so they’re often damaged first’.

One study by University College London on men and women in their 40s found giving up alcohol for a month to be ‘as effective as taking a drug to lower blood pressure, decreasing it by around

5 per cent,’ according to co-author Dr Gautam Mehta, a senior lecturer at UCL’s Institute for Liver and Digestive Health.

After 30 days: The liver regenerates

Although the liver takes around an hour to break down a unit of alcohol, there can be a ‘lag’ in the elimination of enzymes produced as the liver breaks alcohol down, explains Dr Murthy.

‘An enzyme called GGT increases as a protective response to counter the toxic metabolites of ethanol in the liver but can take over a month to reduce back to normal levels in the system.’

High levels of GGT can cause symptoms such as fatigue and abdominal pain. The good news is that, for moderate drinkers, much of the damage caused by drinking will have been reversed. ‘The liver is capable of regenerating up to half of itself within a 30-day period provided the damage has not progressed too far,’ says pharmacist and nutritional therapist Debbie Grayson, who runs gut health clinic Digestion With Confidence.

What happens if I carry on?

Stay sober and damage to the pancreas can recover in six months, while the risk of cancer caused by alcohol – including breast, bowel and mouth – will start to reduce. ‘The longer you quit the better you feel,’ says Porter, while Bee believes that more benefits of sobriety take 90 days to kick in: ‘If you feel tempted to drink every Friday, you won’t get much opportunity to practise changing it this month.

‘You’ll probably finish with Friday nights still feeling like a bit of a test.’

Try 12 sober Fridays – or 90 days’ worth – however and ‘you will start to see a real shift in your thoughts and break that association between Fridays and drinking’. ‘It’s things like that which really impact your overall experience of alcohol-free living.’ 

Why our favourite drinks are getting stronger

Dry January can be a vital way of giving our bodies a break, especially as the alcohol content of many of our favourite drinks has surged in recent years, writes RACHEL HALLIWELL.

The change is partly down to consumer demand. We have developed a taste for powerful, alcohol-laden New World wines, European lagers and craft beers, which contain higher levels of alcohol than similar drinks did a generation ago.

Meanwhile, standard wine glass and shot measures have, in some cases, doubled in size. Pubs and bars used to serve spirits in 25ml measures, the equivalent of one unit of alcohol but the charity Drinkaware says many have now switched to 35ml or 50ml measures.

Standard wine glass sizes used to be 125ml – 1.6 units – but since the 90s, 250ml sizes have been routinely offered in pubs, bars and restaurants.

In addition, wine itself has become stronger. Grapes grown in hotter, sunnier climates contain more sugar, giving the resulting wine a high alcohol content. An Australian shiraz or Chilean malbec can typically reach 14% ABV (alcohol by volume) whereas a traditional Bordeaux will rarely reach more than 13%. The same goes for beer. An average strength craft beer is between 4.8% and 5.2%. But some beer styles, such as barley wine, go much higher. Vault City’s Barleywine beer is 12.2%.

Dr Katherine Severi, chief executive of the Institute of Alcohol Studies, says ­better labelling would help drinkers consume more safely in a landscape where ABVs can vary wildly.

‘A decent wine bar will usually include individual ABVs on its drinks menu,’ she explains. ‘But unless the units per ­serving is also displayed you have to be pretty good at maths to work out the alcohol content being poured into your glass.’

The Chief Medical Officer recommends people drink no more than 14 units of alcohol per week.

Dr Severi adds: ‘Drinking six 175ml glasses of average strength 13% ABV wine across one week would keep you within the low risk guidelines. But the same amount of a 14.5% ABV wine would take you over this level.’