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Effects of alcohol: The good, the bad & the ugly

Ethanol, which is the type of alcohol found in alcoholic beverages, is formed by the fermentation of carbohydrate-dense plants, such as barley, corn and potatoes. While the carbohydrates it comes from are a healthy addition to a balanced diet, ethanol itself is not quite as healthy. The effects of alcohol are in fact toxic, which is why the body tries to break it down as quickly as possible.

Calories in alcohol

With 7kcal per gram, ethanol is richer in calories than carbohydrates or protein (which have 4kcal/g), but less calorie-dense than fat (9kcal/g). With 56kcal per 10ml of alcohol, having a few drinks quickly adds up the calories. And that’s disregarding the other ingredients in drinks, like sugar, cream and fruit juice. Below shows the calorie content of some of Britain’s favourite alcoholic beverages.

  1. A Standard Bottle (330ml) of 5% Alcopop = 237kcal 
  2. A Pint of 5% Strength Beer = 215kcal
  3. A Standard Glass (175ml) of 12% Wine = 126kcal
  4. A Glass (50ml) of 17% Cream Liqueur = 118kcal
  5. A Double Measure (50ml) of 17.5% Fortified Wine = 65kcal


In terms of least calories, the best alcoholic choices include vodka, gin, or tequila or clear liquors with soda, fresh herbs, fresh citrus, bitters, and other aromatics that don’t contribute to the sugar content or calorie content.

The effects of alcohol often lead to overeating, particularly late at night and the following day. Unfortunately, these alcohol-induced feasts don’t tend to be the most healthful of all dishes. All the more reason to ensure to hit the pub prepared and have a proper meal beforehand or carry some emergency snacks in your bag (e.g. unsalted nuts).

Both from a health and from a weight-loss perspective an overconsumption of alcohol is definitely not ideal. However, a G&T or glass of good wine here and there won’t be detrimental.

How does alcohol get broken down and why do we get drunk?

Most of the ethanol we drink is metabolised by the liver. However, there is a limiting factor for the breakdown of ethanol in the liver, which is the enzyme alcohol dehydrogenase (ADH). The average amount of ethanol that can be broken down (oxidised) per hour is 15 grams – which is approximately one unit of alcohol. A unit of alcohol is less than a small glass of wine and less than a half pint of beer. In fact, a large glass (250ml) of average-strength wine (ABV 12%) is 3 units, meaning it takes 3 hours to metabolise. Similarly, a pint of higher-strength lager, beer or cider (ABV 5.2%) also contains 3 units and also takes 3 hours to metabolise. Any alcohol that is not broken down increases your blood-alcohol and is what makes us drunk.

What can influence the speed of getting drunk?

The rates of ethanol absorption are affected by many variables, including:

  • total body water
  • fat composition
  • the alcoholic content of your drink of choice the rate that your stomach empties
  • the presence or absence of food taken in with alcohol
  • the gender and ethnicity of the drinker


For instance, eating a large meal before you drink slows down the effects of alcohol. This is because when alcohol is combined with food it stays longer in the stomach and released into the blood stream at a slower rate. That’s why drinking on an empty stomach is not advisable. Food rich in fat and protein slows down the rate at which food leaves the stomach the most, so an avocado wrap or some salmon sushi before hitting the pub would be ideal.

Mixers and Mixing Drinks

The choice of drink also makes a difference. Fizzy alcohol will make you feel the effects of alcohol more quickly as the bubbles increase the pressure in your stomach, forcing alcohol into your bloodstream faster. Mixing drinks doesn’t make a difference on how drunk you get. Your blood alcohol content is the only determining factor. Mixing drinks may make you sicker by upsetting your stomach, but not more intoxicated.


Gender plays a role in alcohol absorption as women typically have higher peak alcohol levels so the effects of alcohol reach them more quickly than men for a couple of reasons. Firstly, men tend to have bigger physiques and more body water content than women.
Women are also thought to have less of the enzyme ADH, meaning they can’t breakdown alcohol as effectively. Aside from needing less alcohol to see its effects, another point for ladies to consider is hormones. If you’re battling a hormonal imbalance, drinking alcohol isn’t going to be the best option for you. Alcohol can throw hormonal balance off by increasing cortisol and oestrogen while decreasing progesterone.


In terms of ethnicity, there’s genetic mutation of the enzyme ADH can cause a flush response (facial reddening) and higher intoxication in people that have it. This mutation is present in 30 to 60% of individuals of East Asian origin.


Hydration status is key when consuming alcohol. Making sure to drink water is important for a few reasons:

  1. Water will dilute the alcohol in the blood, delaying the effects of the ethanol
  2. Alcohol inhibits the production of anti-diuretic hormone, which makes you need to urinate more. This can lead to dehydration
  3. Dehydration is one of the main reasons for a hangover, so to ease symptoms the following day, ensure to drink a couple of glasses of water before you go to sleep the night before.

With the above points in mind, make sure you respect your limits next time you hit the bar.