It goes without saying that alcohol consumption and fitness don't exactly go hand in hand. But what are the specific effects of alcohol on fitness goals? How does alcohol impact weight loss, muscle building, and your overall health?
“The Fourth Macronutrient”
A macronutrient is a type of nutrient that is required by the body in relatively large amounts. These nutrients include carbohydrates, protein, and fat, which are all necessary to maintain proper health and energy levels. Each of these macronutrients serves a different function in the body, playing important roles in everything from cell growth to hormone production. For example, carbohydrates are the main source of energy for most cells and tissues, while protein helps to build new cells and repair damaged tissue. Fat is also essential as a source of fuel, as well as an important component of many hormones.
Each of these macronutrients have their own caloric content - which is the amount of energy a gram of each macronutrient produces. Proteins and carbohydrates produce four calories per gram, while Fat contains nearly double, with nine calories per gram.
Ethyl-alcohol, the only “safely” consumable form of alcohol, has been called “the fourth macronutrient” because it too has a calorie content. With ~7.1 calories per gram, alcohol is very calorie dense. Unlike proteins, carbs, and fats, alcohol has little to no nutritive value, meaning that it serves no function in the human body.
7 calories may not sound like much, but once you consider that a standard drink contains roughly 14 grams of alcohol per serving, and typically contains carbs like sugar, it’s easy to understand how quickly the calories can add up.
Standard Drink Math
(Answer at the bottom)
Toxicity and Prioritization
Around 90% of absorbed alcohol is metabolized in the liver by an enzyme called alcohol dehydrogenase (ADH) which results in two products - NADH and Acetaldehyde. Acetaldehyde is extremely toxic to the body, causing cell damage and disrupting key bodily functions. Because of this, the liver prioritizes metabolizing it above other macronutrients to prevent further possible damage.
The product of acetaldehyde metabolization, acetate, provides ample energy for many bodily processes, reducing the body’s need to break down fat stores for energy. With energy needs met, carbs and fats consumed with alcohol will be treated like any other caloric excess and be stored for later - making it particularly difficult for weight loss. So for those trying to change their body composition, frequent alcohol consumption is incredibly counter-productive.
Alcohol and MPS
In a 2014 study, researchers tested the hypothesis that alcohol consumption following concurrent exercise decreases muscle protein synthesis, therefore decreasing possible muscle growth. They found that even when alcohol was consumed with protein, alcohol suppressed the anabolic response rates in skeletal muscle tissues, which may “impair recovery and adaptation to training and/or subsequent performance.” So, hitting the bar after a tough workout or won game may hinder your body’s ability to recover and build muscle.
While evidence shows that drinking can be a major roadblock for those looking to change their bloody composition, alcohol consumption is an individual’s decision to take into account when assessing habits that support or hinder your goals.
Math answer & explanation: 1 standard drink has 14g of alcohol per serving. 1 gram of alcohol contains 7.1 calories. 14 x 7.1 = 99.1 calories per drink (without accounting for any other macronutrients). 5 Standard drinks would be ~ 497 calories, or about 25% of the recommended daily caloric intake (USDA)