You probably learned in eighth grade health class that alcohol is a depressant that acts on the central nervous system, can get you drunk, and is all-around bad for you. What you probably learned later is that alcohol can also boost your confidence, help you feel more relaxed, and turn you into a damned good dancer! Alas, the tale doesn't terminate there.
Despite the fun you can have with "liquid courage," it's important to know that excessive long-term usage can result in several severe health consequences like liver damage or addiction. Moreover, if you're worried at all about the size of your gut, alcohol's seven calories per gram and impact on fat storage can wreak havoc on body composition.
In other words, if you want to build an elite physique, smashing beer probably isn't the best way to make it happen. But you likely already knew that. What you might not know, however, is specifically what alcohol does inside your body and how it might impact your ability to burn fat. Drink up some knowledge and learn what alcohol means for your goals!
Alcohol A Shot of Science
As far as your body can tell, alcohol is a toxin. Think of your body's food digestion, absorption, and storage system as a big multibutton dashboard. On this metabolic console is a large, red "pause" button. When you consume alcohol, your body pushes that pause button. As a result, nutrient regulation—what you consume and how your body uses it for energy—is put on hold as the body shifts its priority to processing the alcohol.
Once it's consumed, alcohol (ethanol to you science peeps) is broken down into acetaldehyde and something called nicotinamide adenine dinucleotide (NADH) by the enzyme alcohol dehydrogenase (ADH).2 You'd probably never guess it, but it's this very process that sparks unfavorable changes in nutrient storage and body composition.
As the diagram shows, the end product of alcohol breakdown is acetyl-CoA, which is a molecule that's heavily involved with fatty acid synthesis, or the creation of fat molecules. An excessive build-up of acetyl-CoA can lead to increased formation of fatty acids, which eventually leads to increased fat storage.
Additionally, an increase in NADH (produced as a result of alcohol breakdown) signals to the body that there's a lot of energy (calories) available. The body naturally wants to store that energy, which means that an increase in NADH also favors fatty acid formation and storage. 2
Over time, these molecules create a change in your body to prioritize fatty acid storage. It probably goes without saying, but this change presents quite a challenge if you're trying to reach hyper-shredded status.
Studies for Support
Now, I don't want to be a killjoy. Trust me, I enjoy a tasty beverage just as much as the next guy. (Maybe more, depending on who the next guy is.) But we shouldn't ignore some of the data floating around out there. For example, in a groundbreaking study published in the Journal of Clinical Investigation, researchers observed the effects of alcohol ingestion on carbohydrate, fat, and protein metabolism.
The researchers assessed fatty acid and glucose usage over a four-hour time span. To do it, they infused the subjects with simultaneous delivery of both glucose and insulin through an IV. Researchers then collected blood samples at 0, 30, and every 15 minutes thereafter to determine how the subjects were using fuel.
Two hours into the experiment, the glucose infusion was replaced with an alcohol infusion equivalent to two standard drinks. Upon the alcohol infusion, rates of fat oxidation dropped 87 percent!3 So, instead of using fat for fuel, the subjects' bodies actually began using alcohol for energy. Rates of fat oxidation remained depressed for more than four hours after the alcohol infusion, which is bad news for anyone who wants to burn fat.
Although there is a huge variation in the speed at which each individual body can break down and rid itself of alcohol, it's probably safe to assume that even a small amount of alcohol will stay in your body long enough to put a dent in fat breakdown.4
The same researchers also infused subjects with alcohol and glucose at the same time. Since many of us like to have a few carbs alongside our drinks, this next bit of information is particularly telling: The results demonstrated that simultaneous infusion of alcohol and glucose reduced fat-oxidation rates to nearly 0 milligrams per minute!3
In practical terms, consuming chips and salsa with your beer during the big game is actually dropping your fat-oxidation rates to nearly zero. If you pair carb-heavy snacks and alcohol often, you're stuck with a lot of excess calories that basically aren't being used. That means they're almost certainly going to be stored as fat. And, as even the poorest eighth grade student can tell you, too much fat storage is no good.
Even small amounts of alcohol ingestion will temporarily pause fat breakdown. Research also suggests that consuming alcohol causes overall net decreases in fatty acid breakdown and an increase in storage.5 If alcohol is abused consistently for a longer period of time, this increased storage can turn your uphill fat-loss battle into an unconquerable feat.
Although alcohol in moderation has been shown to provide some health benefits, like reduced blood pressure, there's just no way you'll achieve your dream physique if you're consistently drinking and eating too much. The best way to balance your life with your physique goals is to keep your alcohol consumption to 1-2 drinks no more than twice a week, and refrain from snacking with wild abandon.
- Rimm, E. B., Klatsky, A., Grobbee, D., & Stampfer, M. J. (1996). Review of moderate alcohol consumption and reduced risk of coronary heart disease: is the effect due to beer, wine, or spirits? BMJ, 312(7033), 731-736.
- Bullock, C. (2010). The Biochemistry of Alcohol Metabolism—A Brief Review. Biochemical Education, 18(2), 62-66.
- Shelmet, J.J., Reichard, G.A., Skutches, C.L., Hoeldtke, R.D., Owen, O.E. and Boden, G. (1998). Ethanol Causes Acute Inhibition of Carbohydrate, Fat, and Protein Oxidation and Insulin Resistance. Journal of Clinical Investigation, 81(4), 1137-1145.
- Cederbaum, A. (2012). Alcohol Metabolism. Journal of Clinical Liver Disease, 16(4), 667-685.
- Suter, P.M., Schutz, Y. & Jequier, E. (1992). The Effect of Ethanol on Fat Storage in Healthy Subjects. New England Journal of Medicine, 326(15), 983-987.