Alcoholic drinks represent ‘empty calories’, meaning they are high in kilojoules but do not deliver any nutritional benefit.1

Alcohol (and their calories) are generally consumed in addition to the food and drink people normally consume.2 People who drink alcohol can often also choose less healthy food options, including those high in fat, sugar, salt and kilojoules (kJ), when drinking or the day after.3 Over time, consuming more kilojoules than you need and not eating enough healthy foods can increase the risk of weight gain and other health issues linked to poor diets.

Reading: Best food to absorb alcohol

Table of Contents

Alcohol and weight gain

Weight gain occurs when there is a sustained energy imbalance. For example, when energy (calorie) intake from eating and drinking is greater than energy lost through physical activity,4 weight gain can occur.

Regularly drinking alcohol can contribute to weight gain and obesity,5 which increases the risk of heart disease, stroke, type 2 diabetes, and 13 types of cancer.46

Drinking alcohol can lead to weight gain in three ways:

1. Alcohol contains a lot of kilojoules

Each gram of pure alcohol has 29 kJ.5 In Australia, one standard drink contains 10 grams of alcohol, which provides 290 kJ of energy from the alcohol alone. However, the drinks served in restaurants, pubs and at home are often much larger than one standard drink. For example, a glass of wine served at a restaurant is often around 150 mL, which is 1.5 standard drinks. This means the amount of kilojoules you consume from alcohol is actually even higher.

The National Health and Medical Research Council Australian Guidelines to Reduce Health Risks from Drinking Alcohol recommend having no more than 10 standard drinks a week to reduce the risk of harm over a lifetime. If someone drinks two full strength beers (375mL) or two glasses of wine (150mL) each day, this equates to approximately three standard drinks and represents 10% of the total daily energy intake.8

2. Sweet additions

When mixed with sugary drinks (i.e. mixers), alcoholic drinks contain even more calories. For example, a can of soft drink with two shots of whiskey contains approximately 1,200 kJs,9 which is equivalent to the kilojoules in a small meal.

3. Impact on food choices

Alcohol use can actually stimulate increased food intake,3 so its not just the alcohol that increases overall calorie intake.

For example, studies have shown that when alcohol is consumed before or with meals, food intake is greater by as much as up to 30%.3

Drinking alcohol can also increase the desire for foods high in fat, salt, sugar and kilojoules from take-away, like burgers, kebabs and pizzas. Cravings for these types of foods can occur when drinking, but also when ‘hungover’ the next day.3

“Making up” for drinking alcohol

Reducing the amount you eat or exercising more to compensate for extra kilojoules from alcohol can impact both your physical and mental health.10

Limiting the amount of alcohol you drink to reduce your kilojoule intake is a heathier choice than trying to offset the kilojoule load in other ways.

Alcohol and nutrient absorption

Unlike food, alcohol is not digested. Instead, it is absorbed directly in the blood stream.11

Alcohol begins its journey through the digestive system in the mouth, where it then travels down the oesophagus to the stomach, where some of the alcohol is absorbed into the bloodstream.11 The stomach starts the breakdown of alcohol with an enzyme called alcohol dehydrogenase.12 The rest of the alcohol travels to the small intestine where the remainder gets absorbed. On an empty stomach, it takes around 30 minutes for the alcohol in one standard drink to enter the bloodstream and 60 minutes on a full stomach.11 The liver is responsible for breaking down the alcohol and removing it from the bloodstream.11

The small intestine is the organ in which nutrients are mostly absorbed into the bloodstream.12 Because alcohol causes damage to the organs involved in digesting, absorbing and processing nutrients, it can lead to nutrient deficiencies in those who drink at high-risk levels.1213 The key nutrients affected include thiamin, folate, B12, vitamin A, magnesium, calcium, potassium, zinc and folic acid.1114