Standard drink

[1] Many government health guidelines specify low to high risk amounts in units of grams of pure alcohol per day, week, or single occasion.

These government guidelines often illustrate these amounts as standard drinks of various beverages, with their serving sizes indicated.

The sample questionnaire form for the World Health Organization's Alcohol Use Disorders Identification Test (AUDIT) uses 10 g (0.35 oz),[3] and this definition has been adopted by more countries than any other amount.

[1] For comparison, both measurements are shown here, as well as the number of standard drinks contained in 500 millilitres (16.9 US fluid ounces) of 5% ABV beer (a typical large size of beer in Europe, slightly larger than a US pint of 473 mL).

[30] For example, in the United States, a standard drink is defined as 0.6 US fluid ounces (18 ml) of ethanol per serving, which is about 14 grams of alcohol.

In England, a single pub measure (25 ml (0.85 US fl oz)) of a spirit contains one unit.

However, a larger 35 ml (1.2 US fl oz) measure is increasingly used (and in particular is standard in Northern Ireland[34]), which contains 1.4 units of alcohol at 40% ABV.

In Australia, a 30 ml (1.0 US fl oz) shot of spirits (40% ABV) is 0.95 standard drinks.

[36] (The difference between the sexes was due to the typically lower weight and water-to-body-mass ratio of women).

[37] The Times claimed in October 2007 that these limits had been "plucked out of the air" and had no scientific basis.

[38] This was changed after a government study showed that many people were in effect "saving up" their units and using them at the end of the week,[39][40] a form of binge drinking.

[41] An international study[42] of about 6,000 men and 11,000 women for a total of 75,000 person-years found that people who reported that they drank more than a threshold value of 2 units of alcohol a day had a higher risk of fractures than non-drinkers.

As a rough guide, it takes about one hour for the body to metabolise (break down) one UK unit of alcohol, 10 ml (8 grams).

However, this will vary with body weight, sex, age, personal metabolic rate, recent food intake, the type and strength of the alcohol, and medications taken.

[44] In the UK in March 2011, alcohol companies voluntarily pledged to the UK Department of Health to implement a health labelling scheme to provide more information about responsible drinking on alcohol labels and containers.

Compared with labels from 2008 on a like-for-like basis, information on Unit alcohol content had increased by 46%; 91% of products displayed alcohol and pregnancy warnings (18% in 2008); and 75% showed the Chief Medical Officers' lower risk daily guidelines (6% in 2008).

[49] Studies published in 2021 in the UK showed that the label could be further enhanced by including pictures of units and a statement of the drinking guidelines - this would help people understand the recommended limits better.