What Is Moderate Drinking?

Alcohol Research & Health, Wntr, 1999 by Mary C. Dufour

* Abstainer: drinks less than 0.01 fl oz alcohol per day (i.e., fewer than 12 drinks in the past year)

* Light drinker: drinks 0.01 to 0.21 fl oz alcohol per day (i.e., 1 to 13 drinks per month)

* Moderate drinker: drinks 0.22 to 1.00 fl oz alcohol per day (i.e., 4 to 14 drinks per week)

* Heavier drinker: drinks more than 1.00 fl oz alcohol per day (i.e., more than 2 drinks per day).

To some degree, discrepancies in the definition of moderate drinking may result from the fact that some people confuse the term with "social drinking" - that is, drinking patterns that are accepted by the society in which they occur. Depending on the society, however, those drinking levels may not be moderate or risk free.

Even when a definition of moderate drinking has been developed, that definition may not apply equally to all people or under all circumstances. For example, although it may not be harmful for a party's host to consume three or four drinks during the evening, the same amount of alcohol when consumed by a guest who plans on driving home could place the guest at risk for being in a car crash. Similarly, a healthy woman will likely experience no negative effects from drinking one drink per day; however, if the woman is pregnant, the same drinking level may lead to adverse effects (i.e., fetal impairment).

In addition to the circumstances under which drinking occurs, alcohol's effects on the drinker (e.g., on the ability to drive a car) depend to a large extent on the blood alcohol levels (BALs) achieved after alcohol consumption. The same number of drinks, however, will result in different BALs in a 150 pound (lb) and a 250 lb person. Even people with identical body weights can achieve different BALs because of variations in the levels of water and fat in the body, which primarily depend on the drinker's age and gender. Alcohol is a small, water-soluble molecule that is distributed throughout the body water. Women tend to have proportionately less body water and more body fat than do men and therefore may achieve higher BALs than do men with the same body weight after drinking the same alcohol amount. Similarly, body water generally decreases and body fat increases with increasing age. As a result of these physiological differences, the same number of drinks will result in different BALs in a 140 lb woman and a 140 lb man, or in a 20-year-old man and a 60-year-old man with identical body weights.

Moderate Drinking Guidelines

One of the most compelling reasons for collecting data on alcohol consumption and for developing models of alcohol-related risks and benefits is the desire to determine "safe" or "low-risk" levels and patterns of alcohol consumption(2) - that is, consumption levels below which drinking is not strongly associated with negative consequences. In fact, when people ask, "What is moderate drinking?" what they often really want to know is how much alcohol is safe or sensible to drink or how much they can drink without being at high risk of incurring negative consequences.