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Does Alcohol Prevent Weight Loss, or Cause Fat Gain?

By John Leyva / July 1, 2017

Did you know that alcohol consumption can decrease testosterone in men by 23%? What about how alcohol directly affects your ability to lose fat?

Alcohol is deeply entrenched in our culture as a way to have fun, let loose, and be social. Companies that market alcohol from vodka, to whiskey, to beer know the right buttons to push. Our brains are seemingly wired to desire a cold refreshing alcoholic beverage after a tough day at work.

But, the truth is that alcohol, when not consumed in moderation (1-2 drinks a few times per week) has very negative effects on weight loss. This article will delve into the physiology of how alcohol affects your ability to successfully lose weight and keep it off for good.

What is a “Drink” of Alcohol?

Research considers an alcoholic drink to be about 15 grams of ethanol alcohol. Fifteen grams of alcohol is found in 5 ounces of wine, 1 1/2 ounces of an 80 proof/40% drink such as vodka or whiskey, and 12 ounces of beer. Because these are general guidelines, clearly some drinks may be stronger than others. For example, light beer is slightly weaker than regular beer. Most restaurants and bars serve 16 oz beers (making it one and a third drink) while pouring more than 1 1/2 ounces in a mixed drink.

Every gram of alcohol that you drink counts for 7.1 calories. However, because you burn up some of those as your body processes them (thermic effect), the total calorie per gram is closer to 5.7.

Let’s say you order a beer at dinner. With 20 grams of alcohol x 5.7 calories + the total amount of carbs, you end up with a drink that contains 150 calories. The range of caloric intake for beers ranges from 64-250+. Wine and shots also average about the same amount of calories. Watch out for mixed drinks, because besides the alcoholic calories they inherently have, depending on what’s mixed in, you could be drinking an excessive amount of calories in just one drink.

Alcohol & Weight Loss | After Your First Two Drinks

After your first drink, your body starts to get rid of the alcohol quickly using the alcohol dehydrogenase (ADH) pathway.1 In this pathway, ADH converts the alcohol into acetaldehyde, which gets further broken down to acetate. These by-products (acetaldehyde and acetate) are considered to be highly reactive and can increase oxidation throughout the body, but especially in the liver.

Because your body sees these by-products as dangerous, it wants to use them as fuel. This means your body will significantly blunt fat-burning close to 75% after just one and a half drinks.2 And it will stop using carbs for energy. Therefore, although very little alcohol will be stored as fat (less than 5%), the fat and carbs you are eating have an increased risk of being stored as fat.

Your liver can process these toxins through the increased use of certain vitamins, such as the water soluble vitamins B1, B3, B6, folate and C, while also possibly depleting some of the fat-soluble vitamins, A, E and K1. Over-time these decreases in vitamins can play a secondary role in loss of motivation, energy, and well-being.

After your first couple of drinks, your brain also starts to increase its usage of GABA. GABA is an inhibitory neurotransmitter in the brain and is a large reason why alcohol is known as a “depressant.” Over time, the GABA receptors get used to the effects of alcohol, which is a reason why people may need more and more alcohol to feel the effects from alcohol consumption.3 GABA is also the neurotransmitter, principally responsible for allowing you to stay asleep. Therefore when your brain uses more of it before you go to sleep, you have less while you’re actually sleeping, causing a disruption in restful sleep.

Alcohol also affects the higher processing areas of the brain, the cerebral cortex, while leaving the lower areas of the brain somewhat unaffected. This leaves you more emotional than you would normally be. If you’ve ever experienced “drunk logic” while doing or saying things you would never think to do sober, then you’ve experienced the inhibitory effects of having your cerebral cortex taken out of the equation.

While your body has started to use the alcohol as energy, your body releases anti-diuretic hormone (ADH) to help your body rid itself of the alcohol. This basically means that your urine volume increases significantly (about 100 ml per 10 grams of alcohol).4 If you’ve ever “broken the seal,” you know that the more you continue to drink, the more frequently you use the restroom.

Since your kidneys are working over-time, your body releases an increase in certain minerals and electrolytes especially calcium, magnesium, copper, selenium and manganese. All of these play important roles not only in blood volume, but in bone health, blood pressure and the anti-oxidant pathways.

In addition to everything above, a small increase in cortisol typically occurs with moderate drinking while testosterone levels will drop about 6.8% in men (not so much in women).5 Aromatase will also increase. Aromatase is an enzyme that helps to convert testosterone to estrogen and is obviously not something that is welcomed by many guys.

Alcohol & Weight Loss | After Six to Eight Plus Drinks

If you’re drinking a moderate amount of alcohol, those things listed above are the main effects, at least short-term. If you drink heavily and drink often, another system called the Microsomal Ethanol-Oxidizing System (MEOS) system kicks in at the point when the ADH pathway becomes overwhelmed.

This system is interesting because it causes your body to generally burn off more energy as useless heat and probably saves your life from too high of a blood alcohol level. It is primarily controlled by a special enzyme that plays an important role in utilizing certain medications and the metabolism of fatty acids. This increased rate of medication breakdown can decrease their effectiveness, while the incomplete breakdown of fatty acids can cause an increase in oxidation. This increase in oxidation becomes exacerbated as the body’s main anti-oxidant (glutathione) is also impaired, decreasing your ability to fight the oxidation.

As your drinking levels continue to increase, testosterone levels drop from 6.8% with 4 drinks to 23% with 8 drinks.6 This drop, combined with a slowdown in protein synthesis, can cause havoc when trying to recover from a workout.

In addition to that, fluid loss will generally become more significant, causing dehydration that might affect you for days afterwards. Finally, with heavy drinking, the breakdown of alcohol can occur for up to 48 hours after your last drink. This means less glucose is reaching your brain and working muscles, making you both more tired and quicker to fatigue if you do exercise.

If You’re Going to Drink Alcohol, Drink in Moderation and Not Too Often

You would think after listing all that happens in your body after consuming alcohol, the no-brainer suggestion would be to not drink. What is missing though are some of the benefits from consuming moderate amounts of alcohol.

Alcohol is shown to increase insulin sensitivity, which basically means that your body needs less insulin to do its job. In addition to that, research has shown that women who drink a moderate amount will have the same or slightly lower BMI, as those who don’t drink.7 The same effect is not seen in men. Those who moderately drink are also at less risk of dying from heart disease and cancer while decreasing one’s risk of Alzheimer’s8 and even slightly improving your immune system.9

In other words, complete abstinence may not be needed while trying to lose fat as long as it’s done in moderation and not very often (think one time per week). If you don’t drink, obviously don’t start, but if you want to have a couple of drinks on the weekend, there is nothing necessarily wrong with having one or two. In future articles, I will list some of the best and worst drinks to have when going out and 5 strategies you can implement to decrease the deleterious effects of having a night of heavy drinking.

Alcohol & Weight Loss | Wrapping It Up

In any fat loss plan, there are three main components that should be priority: Diet, Exercise, and Sleep.

As stated throughout the article, a moderate amount of alcohol can increase total calories, decrease your motivation for exercise, and negatively affect your sleep. Despite this, many people can enjoy a drink or two, without throwing those three components completely out of whack.

On the other hand, drinking heavily can significantly derail energy levels, has a larger influence on dehydration, negatively impacts hormonal levels, and can significantly disrupt your sleep. Therefore, limit your overall levels of alcohol and put yourself in the best position to reap some of the benefits of alcohol consumption, while not derailing your overall progress.

What do you think of the article? Anything new that you learned? Have any questions?

Show 9 References

  1. Lieber, Charles S. Relationships Between Nutrition, Alcohol Use, and Liver Disease. National Institute of Health: NIAAA (2004).
  2. Siler, S.Q., Neese, R.A., & Hellerstein, M.K. (1999). De novo lipogenesis, lipid kinetics, and whole-body lipid balances in humans after acute alcohol consumption. American Journal of Clinical Nutrition, 70, 928-936
  3. Available at: http://chemcases.com/alcohol/index.htm. Accessed November 10, 2012.
  4. Eggleton MG. The diuretic action of alcohol in man. J Physiol. 1942 Aug 18;101(2):172-91.
  5. Sierksma A, et al. Effect of moderate alcohol consumption on plasma dehydroepiandrosterone sulfate, testosterone, and estradiol levels in middle-aged men and postmenopausal women: a diet-controlled intervention study. Alcohol Clin Exp Res. 2004 May;28(5):780-5. Hat-tip: Alan Aragon
  6. Välimäki M, Tuominen JA, Huhtaniemi I, Ylikahri R. The pulsatile secretion of gonadotropins and growth hormone, and the biological activity of luteinizing hormone in men acutely intoxicated with ethanol. Alcohol Clin Exp Res. 1990;14(6):928-31
  7. Flechtner-Mors, M., Biesalski, H.K., Jenkinson, C.P., Adler, G., & Ditschuneit, H.H. (2004). Effects of moderate consumption of white wine on weight loss in overweight and obese subjects. International Journal of Obesity and Related Metabolic Disorders, 28, 1420-1426
  8. Letenneur L. Risk of dementia and alcohol and wine consumption: a review of recent results. Biol Res. 2004;37(2):189-93.
  9. Romeo J, Warnberg J. (2007). Moderate alcohol consumption and the immune system: a review. Br J Nutr. 2007, Oct; 98 Suppl1: S111-5


  • jeff says:

    Very informative. However, this article got me so bummed out about the effects of alcohol, I gotta go out and have a drink :)

  • Jeff Toscano says:

    Wow, very informing article. Will definitely keep in mind and pass along.

  • Dave says:

    Everyone in NYC should read this article, it's amazing

  • neil thomas says:

    I alway quit drinking in the month of january. I am of average weight age 66, but I
    do not lose 1 lb. I continue to ride my mountain bike and workout 3 times a week..What's up????...neil

  • David says:

    It is still possible to drink and be in phenomenal shape. The only kicker is that you have to work that much harder if you do decide to drink. Also, there is always the danger of blacking out the day after if you decide to lift heavy.

    Interesting facts about GABA!

  • Dhruv Bhagat says:

    Hi John,

    I know some of the benefits of wine.. Yeah, it does lose your weight..
    It also lowers risk of heart diseases, reduces high blood pressure, improve brain functionality, reduces risk of cataracts, and even prevents sunburn...

    Anyways, thanks for the detailed post :)

  • Landon says:

    I do a fair amount of reading and up until now have not seen such a thorough article on the subject. Thanks for the great job you all do at BuiltLean.

  • Caleb says:

    I know I'm a little late on this one but Ive been recently struggling with alcohol and weight loss, weight training and trying to eat 2000 calories a day and not drink throughout the week. I've been doing terrible at it thus causing me to binge eat when I drink. It's hard, and depressing. Im at 275 and need to get down to at least 215, but I want to lose all fat and not muscle and I don't know how much of that is fat. Anyway, if you see this. Throw some prayers my way for me to stay strong and lose this terrible habit. Thanks man, and great article by the way.

  • Kitty Hausner says:

    I truly enjoy reading through on this internet site, it contains great content. “Sometime they’ll give a war and nobody will come.” by Carl Sandburg.

    • Kristin Rooke, CPT says:

      Glad you're enjoying the site, and thanks for sharing the quote!
      -Kristin, BuiltLean Coach & Managing Editor

  • suzette says:

    thanks a well documented and balanced article .I sort of knew about negative effects of alcohol on weight loss ,but can always find reasons to continue.So if total abstinence and misery is not the only way ,am now happier to tackle the big factor on struggle to lose weight despite lots of cardio and strength training and being fit .Thanks again

    • Marc Perry, CSCS, CPT says:

      Thanks for sharing your thoughts, Suzanne. Good luck!