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How does alcohol cause weight gain?

Tamara Willner
Written by

Tamara Willner

Medically reviewed by

Fiona Moncrieff

6 min read
Last updated July 2024

You may or may not be surprised to hear that alcohol consumption can significantly affect your weight, but not necessarily in the way you might think.

There are several direct and indirect ways that heavy drinking can make you gain weight or, more specifically, gain body fat.

So how does alcohol cause weight gain? The three effects are:

  1. Direct effect – excess energy: Alcohol, or ethanol, is very calorie-dense at 7 per gram, and it’s easy to over-consume.
  2. Indirect effect – alcohol’s tipping point: When you drink more than 3-4 drinks, your inhibitions drop, and you’re more likely to make poor food choices later on, sometimes lasting up to 48 hours.
  3. Indirect effect – poor sleep quality: Alcohol can harm your sleep quality. Poor sleep quality is strongly associated with increased energy intake.

Heavy alcohol use is one of the leading factors in the development of obesity and chronic diseases.

People who tend to drink more have a higher risk of developing obesity, high blood pressure, fatty liver, type 2 diabetes (high blood sugar levels), and the infamous ‘beer belly’, a high level of belly fat (the technical term being visceral fat).

You might be concerned about your weight and whether your alcohol intake prevents you from losing weight.

At Second Nature, you’re provided with a registered nutritionist or dietitian who can support you manage your alcohol intake to suit your lifestyle and preferences.

If you’d like to give us a go, click here to try our weight loss calculator to see how much you could lose with Second Nature.

Otherwise, keep reading as we look at the three ways alcohol can lead to higher body weight, waistline, and health problems in the long term.

1) Direct effect: excess energy

When people discuss alcohol’s effect on weight, they typically refer to the calories in alcohol as the leading cause of weight gain.

These numbers are significant; alcohol is a very high-calorie product and provides 7 calories per gram.

Therefore, alcohol consumption within the government guidelines of up to 14 units per week for men and women can provide almost 3,000 extra calories per week if choosing the highest calorie option.

For heavy drinkers, this number is significantly higher.

That can be over a day’s worth of energy from the alcohol. Plus, most alcoholic beverages have a lot of energy but little nutritional value, which is where the term ‘empty calories’ comes from.

However, increased energy intake from alcoholic beverages is not the main reason excessive alcohol results in weight gain. What’s more interesting is the number of ways excessive alcohol affects your weight indirectly.

Key point:

  • Alcohol provides a lot of energy, and it can be easy to consume too much.

2) Indirect effect: alcohol’s tipping point

Alcohol has a ‘tipping point’. This refers to the amount of alcohol it takes for your inhibitions to be significantly lowered such that your energy intake substantially increases over the following 48 hours.

A recent research survey reported that the average tipping point – the point at which people go on to make poor choices with food and alcohol – is 9.3 units of alcohol. This is equivalent to only 3.7 pints of beer or 3.1 large glasses of wine.

Pyramid diagram illustrating the average tipping point of 3-4 alcoholic drinks.

The average additional energy intake after a person has passed their tipping point is estimated to be 4,305 extra calories that same evening – more than twice the recommended daily calorie guideline for an adult woman.

The survey also highlighted that the day after passing their tipping point, 50% of people cancel planned physical activity, often replaced with sedentary activities such as watching TV or staying in bed.

People continue to make poor food choices the day after passing their tipping point, with an average additional intake of 2,051 calories, taking the estimated additional calorie intake to over 6,000 in two days.

Let’s just let that settle in; having 3-4 pints of beer or 3 large glasses of wine can indirectly increase your calorie intake by over 6,000 calories in the following two days!

Most of us are probably aware that we prefer stodgy foods after drinking and are less inclined to be active the next day, but it can be pretty surprising when the numbers are added up.

Key points:

  • Alcohol’s ‘tipping point’ refers to the amount of alcohol it takes to significantly lower our inhibitions and affects our choices.
  • 3-4 drinks seem to be the average tipping point.
  • Poor decisions after drinking and reaching our tipping point can last up to 48 hours.

3) Indirect effect: poor sleep quality

As well as the result of passing your tipping point, research shows that poor sleep quality following binge drinking significantly affects weight.

Drinking alcohol close to bedtime is initially a sleep aid; this is where the idea of ‘a drink before bed’ came from. However, alcohol impacts the critical stages of your sleep, such as deep and REM sleep.

While you might initially fall into deep sleep more quickly, you wake up frequently at night and have poorer sleep overall. Also, you experience less REM sleep, meaning you can wake up exhausted.

Additionally, alcohol is a diuretic, meaning you lose more body water, so you’ll likely need to go to the bathroom more frequently and will often sweat more too.

A lack of sleep, or poor quality of sleep, increases your appetite and cravings for junk food rich in refined carbohydrates and decreases your energy expenditure on the following day.

Key points:

  • Drinking alcohol reduces the quality of your sleep.
  • Poor sleep increases appetite, cravings for junk food and decrease energy expenditure, which all indirectly lead to weight gain.

Do you need to give up alcohol to lose weight?

The simple answer is no.

Eliminating alcohol is not necessary to lead a healthy lifestyle. It is perfectly fine to enjoy a glass of red wine with a meal, for example. The problem arises when people binge drink, i.e. having 3-4+ glasses of wine or pints of beer at once.

It’s essential to be aware of both the direct and indirect effects of alcohol on your weight. If you’re determined to improve your health and lose some weight, one of the most effective things you can do is cut out binge drinking.

By cutting back on binge drinking, you could inadvertently lose weight to achieve a lower body mass index (BMI) without making any other changes to your lifestyle.

Key points:

  • Eliminating alcohol is not necessary for weight loss; there is nothing wrong with enjoying a drink.
  • Binge drinking results in problems for weight loss.

Practical tips to reduce alcohol intake

  1. Set yourself a challenge to not drink alcohol during the week.
  2. Try to limit yourself to 1-2 alcoholic drinks at a time and leave the bottle of wine out of sight after you’ve poured a glass.
  3. When you do drink, have it over a relaxing meal or with friends and enjoy it, rather than mindlessly drinking while distracted in front of the tv.
  4. At social events, try alternating between sparkling water and alcoholic beverages.
  5. Choose long drinks so the alcohol is less concentrated and the drink lasts longer (e.g. white wine and soda water spritzer or a single gin and tonic in a tall glass)
  6. Offer to be the designated driver – a good excuse to have no alcohol.

Take home message

  • There is nothing wrong with having 1 or 2 drinks occasionally over a meal or in social situations.
  • Binge drinking (roughly defined as 3+ drinks in one sitting) can, directly and indirectly, affect your weight and health.
  • Alongside weight, excess alcohol consumption can lead to liver disease and other chronic health conditions like type 2 diabetes.
  • Directly drinking alcohol makes consuming an excess of energy very easy.
  • Indirectly, binge drinking pushes you over your tipping point, which results in poor decisions that affect your weight in the following 48 hours.
  • Binge drinking also indirectly promotes weight gain by reducing the quality of our sleep, which increases our appetite and cravings while decreasing energy expenditure the following day.
  • It’s not necessary to eliminate alcohol to lead a healthy lifestyle and lose weight, but it’s essential to be mindful of our alcohol intake and reduce binge drinking.
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Write a response

Abby Tameemi

17 November, 2021

I LOVE LOVE LOVE this article!!! I recently experienced a pretty tough life with my ex-husband & then we went through a divorce. This all caused me to drink daily; not excessively but daily. Reading this article is a complete eye opener to why I gained a ton of weight. I can’t thank you enough for writing this article and for putting down facts that will actually help people. You are a great researcher & author. Because of this article, tomorrow I start a new way of living.


5 December, 2021

Hi Abby,

So pleased you found this article helpful! Sorry to hear what you’ve been through and congratulations on the steps you’re taking toward a healthier lifestyle 😊💪

If you’d like to learn more about our programme, you can take our health quiz here, or email with any questions.

Sophia Beckett

13 August, 2021

I can manage sticking to a max of 2 glasses wine at the weekend. This article was very helpful and explained a lot to me. Dropping a glass of wine each ev during the week has not been as bad as I thought…

Sylvia White

9 August, 2019

This is a very interesting article all I have to do is limit myself to 2 drinks on Saturday and I will be ok. Buying the single glass bottle of wine is easiest for me until I reset my mind to only have this amount.

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