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Is Alcohol Bad for Weight loss?

Before reading further, please understand that as a fitness instructor delivering personal training in Clapham, I too enjoy a glass of wine and will continue to do so. The purpose of this post is to identify some of the key reasons how alcohol slows your weight loss results if your fitness goal is to lose weight…And it’s not just about the extra calories!

While it is not my aim to convince you to give up drinking forever (although that will leave more wine available on the planet for me), what this post will hopefully do is help you identify how alcohol affects you, and inspire you to develop a plan to moderate your consumption to keep you on track.

Here are 5 reasons Why alcohol affects weight loss.

 1. Fat becomes the ‘second’ choice as a fuel source

When alcohol is processed through your liver, one of the by-products of this process is acetate. Acetate then becomes the primary source of fuel that your body burns. This leaves the desired source of energy (fat) unused until the alcohol is used first.[i] [ii]

To put this in perspective, after an alcoholic drink, your ability to burn fat will be decreased by a whopping 75%,[iii] until the acetate is used.

What this means is that when you have alcohol in your system, you have an excess of carbohydrate that is not being used as fuel. That excess will wind up being stored (unfortunately) in one place…around your waist.

 Does alcohol stop fat burning | 5 reasons why alcohol affects weight loss | Fit to Last

2. Alcohol slows metabolism and affects blood sugar management

Metabolism is one of the fundamentally important parts of the weight-loss equation. We train to build lean muscle mass so that our metabolism will be more active at rest, thereby burning more calories.

A key function of metabolism is the maintenance of blood sugar levels[iv]. Because your body cannot store alcohol it will metabolise it immediately, at the expense of other bodily functions including blood sugar management[v]. This means that alcohol consumption, even occasional, can result in dramatic blood sugar fluctuations which over time can lead to decreased insulin resistance. Decreased insulin resistance, if left unchecked, is the first step towards Type II Diabetes.

Blood sugar fluctuations | Alcohol slows weight loss | Fit to Last

3. Alcohol leads to disrupted sleep

Alcohol consumption leads to the increased use of the neurotransmitter GABA. GABA is the neurotransmitter that helps you to stay asleep, so when you use more due to alcohol consumption you will have less to keep you asleep, resulting in a broken night’s rest[vi].

Restful sleep is the key to recovery. If your sleep is broken, you are more likely to release the hormone cortisol, which results in increase weight gain around the waist (sleep deprivation has been associated with a 45% increase in plasma cortisol levels[vii]).

The reason why increased cortisol levels lead to increased weight gain is because your body sees increased cortisol as your body being under duress. This leads to an actual resistance to weight loss, as your body attempts to hold on to current body weight for the purpose of self-preservation[viii] Are you seeing a trend developing here?

Alcohol leads to disrupted sleep | Alcohol slows weight loss | Fit to Last

4. Alcohol consumption is not ‘stress relief’

Alcohol consumption is often associated as a successful vehicle to ‘let off steam’ or ‘reduce stress’.

Don’t kid yourself. Alcohol consumption causes a greater secretion of the stress hormone cortisol than the stressful event that inspired the need for a drink in the first place[ix].

Excessive cortisol release is often manifested by stubborn fat collection around the waist.

The HPA axis (Hypothalamus/Pituitary/Adrenal Cortex) is responsible for the control and release of the stress hormone cortisol. Alcohol “depresses the nerve cells responsible for HPA inhibition, thereby elevating HPA axis activity”[x]. Therefore, the unfortunate bi-product of alcohol consumption is that it increases release of the stress hormone cortisol. This can lead to a collection of fat around the stomach.

Alcohol consumption increases release of the stress hormone - Slows down weight loss

5. Alcohol consumption leads to other bad choices

Alcohol also increases your appetite, both for more alcohol and also for food[xi].

Part of the process of weight loss involves nutrition control as well as attaining negative energy balance (using more energy than you consume). While a well-designed nutrition plan will not leave you starving, part of the process of attaining negative energy balance involves paying attention and controlling what you take in.

When we drink alcohol it becomes that much harder to keep those well-laid plans in check. Also, you are more inclined to give in to the food and alcohol cravings, meaning your calorie intake will increase.

Alcohol consumption may be a part of social society, especially here in the UK. But make no mistake, if your mission is to get rid of unwanted belly fat it is imperative, that you take the consequences of alcohol consumption seriously.

Instead, treat its control with the same vigour and determination that you are pursuing your weight loss goals. That will lead to amazing change.

Overeating | 5 reasons why alcohol affects weight loss | Fit to Last

A helpful tip: go two-fisted

Order a glass of water with each alcoholic drink (and drink it!)

You won’t sup your alcoholic drink so quickly and you’ll save yourself from the banging headache the following morning.

Drink water and wine | 5 reasons why alcohol affects weight loss | Fit to Last

To learn more about healthy eating habits to achieve your fitness goals, contact James Staring, a leading personal trainer in Clapham, London.


James StaringJames Staring is a personal trainer based in Clapham, London. His methods have featured in publications such as Your Fitness, Hello, Healthy, Daily Mail, Closer, and many more. After giving up smoking and entering the fitness industry in 2009, James has focused on his passion to help others transform their health and fitness. However, James is convinced that most people struggle so much more than they need to in an effort to improve their fitness. Through his company, Fit to Last, which he runs with his partner, Ali Page – James has helped hundreds of men and women make small adjustments in their daily habits to transform their fitness and to love how they look and feel.


[i] Levya, John: Does Alcohol Prevent Weight Loss, or Cause Fat Gain?:

[ii] Greenfield, B: How alcohol makes you fat:

[iii] Leyva, J: Ibid

[iv] How Alcohol Affects Metabolism:

[v] Ibid.

[vi] Leyva, J: Ibid

[vii] Randall, M: The Physiology of Stress: Cortisol and the Hypothalamic-Pituitary-Adrenal Axis;

[viii] Michaels, J: More Reasons To Whittle your Middle;
[ix] Randall, M: Ibid
[x] Ibid

[xi] Greenfield, B: Ibid

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