The guide

Weight, muscle and the rest of you

By GyroscopeUpdated November 15, 20267 sources

While your body clears alcohol, it burns a lot less fat. After about two drinks, fat burning across the whole body fell 73% in a lab study. A very big night after hard training cut muscle building by up to 37%. And drinkers who took a dry month saw their weight, blood pressure and insulin resistance come down.

There are two popular takes on this, and both miss. One says alcohol turns straight into belly fat. The other says a drink is just calories, so a few won’t matter if you hit your numbers. The measured version sits in between, and it’s more interesting than either. Very little alcohol becomes fat. What it does is make your body stop burning the fat it was going to burn.

Does alcohol turn into fat?

Almost none of it does. In a 1999 study, researchers gave 8 healthy men 24 g of alcohol, about 1.7 US drinks, and traced where it went. The liver’s fat-making pathway did switch on, but the new fat it made was less than 5% of the alcohol.

Most of the alcohol, about 77%, was turned into acetate and sent into the blood, and the body burned that instead of its usual fuel. Fat release from the body’s stores fell 53%, and fat burning across the whole body fell 73%.

It’s like throwing newspaper on a fire. The fire burns the paper first, and the logs sit there until it’s gone. Alcohol is the newspaper, and the fat you were going to burn is the logs, along with whatever you ate that evening.

Then there are the calories themselves. Alcohol carries about 7 calories a gram, so a US drink is about 100 calories from the alcohol alone, a 16 oz IPA about 180 and a bottle of 13.5% wine about 560, before the carbs in the drink and the food that tends to come with it. bodyfat.guide covers what that does to your weight over time, and What’s in your glass counts any pour.

Does alcohol kill your gains?

A very big night can. In a 2014 study, 8 physically active men did a hard session of heavy leg extensions, steady cycling and sprint intervals, three times. After one session they drank a protein shake. After another they had the same shake with alcohol, and after the third they had alcohol with carbs instead of protein. The muscles were sampled over the next 8 hours.

Muscle building still rose above resting levels every time. But compared with protein alone, it was 24% lower with alcohol and protein, and 37% lower with alcohol and carbs.

The dose is the part people leave out. They drank 1.5 g of alcohol per kg of body weight in the hours after training. For a 176 lb man that’s about 120 g, or 8 to 9 US drinks. Nobody has shown that one beer after a workout does this. A team night out after a hard game is a fair match for what was tested.

There’s a second, smaller cost. In the WHOOP data on 20,968 members, physical activity the next day was lower after drinking, and more so the more people drank.

What changes over a dry month?

A 2018 study at one hospital followed 141 moderate to heavy drinkers. Ninety-four of them chose to stop drinking for a month, and 47 chose to carry on. The dry group had been drinking about 258 g a week, roughly 18 US drinks.

After the month, the dry group’s insulin resistance was down 25.9%, their systolic blood pressure (top number) down 6.6% and diastolic (bottom number) down 6.3%, and their weight down 1.5%. Two growth factors tied to cancer fell too. The group that kept drinking didn’t change on any of them, and the changes in the dry group weren’t explained by changes in diet, exercise or smoking.

People picked their own group, so it isn’t a trial, but it gives one of the clearest pictures of what a month off does, and anyone can run the same test on themselves. Cutting back and dry stretches shows how to measure it on your own nights.

What about the rest of your body?

Alcohol touches nearly every organ, and Gyroscope’s old guide went through them one by one, from the brain and gut to hormones, teeth and kidneys. A lot of those claims had no source we could confirm, so this guide keeps only what holds up. The other big effects have their own pages.

• Blood pressure. bloodpressure.guide answers how drinking raises it, including the morning after.
• HRV and heart rate at night. What your watch or ring sees, and hrv.guide for HRV itself.
• Sleep. The two halves of a drinking night.
• Cancer and long-term risk. Cancer, your heart and the long run.

Alcohol and weight loss goes deeper on what alcohol does besides the calories, and 200 calories of beer vs food shows why the same calories land differently.