Hi Dan, can excessive drinking of alcohol really lead to weight gain, and if so, how does this weight gain work?

Just looking at the calorie content of alcoholic drinks you can see how they can contribute to weight gain. Alcohol contains 7 kcal per gram, compare this to the macronutrients and it sits second behind fat (9 kcal/g) and way above carbs (4 kcal/g). To put this into context a shot of vodka is around 50kcal and a pint of beer 220 kcal. 

Not only that but, alcohol isn’t very satiating. No one drinks a glass of wine and thinks they're full. 

In general, liquid calories are an easy way to consume calories without your brain noticing, so when you add the calories from all the other things in your alcoholic drink like starch and sugar, a heavy session can add on a meal’s worth of calories.

There’s also evidence that drinking alcohol leads to the consumption of more calories from the rest of the diet, although the effect appears to be pretty small; half a pound of weight gained for an increase of 2 drinks a day. Other studies have found no effect so results are mixed. 

Interestingly the 'beer belly' myth is exactly that. There’s no indication that beer specifically causes weight gain around your belly, and where fat is deposited is largely down to genetics.

It’s likely that the effect of alcohol on weight gain depends on a few factors including when you drink and how much you drink. You might find that when you are drunk or hungover that you're more likely to reach for fatty and sugary foods or you end up eating more. 

Researchers have looked into why this might be and it appears that alcohol negatively affects both hunger and satiety through the brain and hormones. Alcohol may also inhibit fat oxidation but as I’ve said above, we don’t have real world data to support this.

If this applies to you then be mindful of your eating habits, try and have a bite to eat before drinking and leave some healthier snacks in the house for when you get home.

If in doubt you can probably assume alcohol is not good for your health. There are social aspects to alcohol and that’s up to you to decide how you want to balance that in your life. 

In general though, I will always recommend to moderate your drinking because it can result in a whole host of negative health effects that are unrelated to weight gain.

TL;DR

Yes it can. Although studies have provided mixed results, alcohol provides calories without filling you up and could cause you to over consume calories from other sources too.

Dan Clarke, RNutr

Junior Sustainable Nutrition Manager