Alcohol is a central nervous system depressant and acts as a mild anesthetic and tranquilizer. It is toxic in large quantities.

Alcohol is considered a "macronutrient" in that it provides energy. Energy is measured in calories, and alcohol has about 7 calories per gram. The calories obtained from alcohol are considered to be "empty" because alcohol contains no beneficial nutrients, such as vitamins and minerals.

One-half ounce of pure alcohol, the amount in a 1-ounce shot (2 tablespoons) of liquor, contains approximately 80 to 90 calories. Carbonated beverages or fruit juices contribute additional calories when mixed with alcohol in a cocktail.

Alcohol content of various alcohol-containing beverages:

"Proof" is the alcohol content of distilled liquors. It is the percentage of alcohol (by volume) multiplied by two. For example:

• 100-proof alcohol = 50% alcohol
• 200-proof alcohol = 100% alcohol

The alcohol content of wine is given as a percentage. White wines average 12%, and red wines are around 14%.

The alcohol content of beer is between 3% and 8%. "Light" or lower-calorie beers have fewer calories and are closer to 3% alcohol content. Liqueurs, such as sherry and dessert liqueurs contain 40% to 50% alcohol and tend to be higher in calories.

In terms of alcohol content, 12 oz beer = 5 oz glass of wine = 1 1/2 oz liquor.