Each gram of alcohol has 7 calories. Image Credit: Mpak ART studio | Ilarion Ananiev/iStock/GettyImages

Alcoholic beverages come in many forms, including wine, beer, cider and liquor. Regardless of which drink you prefer, alcohol contains 7 calories per gram, and any calories can contribute to weight gain. The type of alcoholic drink that is the most fattening will likely be the one highest in calories and carbs, and a shot of straight liquor generally has less of both than a 12-ounce beer.

Tip A standard 7-ounce mixed drink and 12-ounce beer typically have the same number of calories and will likely contribute to the same amount of weight gain. However, pure spirits alone contain fewer calories and carbohydrates.

Alcohol and Weight Gain

The Dietary Guidelines for Americans state that people should consume alcohol in moderation, if they choose to do so at all. For women, this means about one drink per day. For men, this means about two drinks per day.

Alcohol contains calories and, depending on the product, is often also carbohydrate-rich. So, although it has minimal nutritional value, it counts toward your daily caloric intake and carbohydrate intake.

Although calorie intake is important, the quality of your diet is also of relevance. Carbohydrates, particularly added sugars, can contribute substantially to weight gain. If you're consuming a diet that is already filled with unhealthy carbs, increasing your carbohydrate and sugar consumption through mixed drinks and beer can contribute substantially to weight gain.

Excessive Drinking and Weight Gain

According to a 2014 study in the American Journal of Public Health, alcohol consumption is not only related to weight gain, but to obesity. A 2015 study in the journal Current Obesity Reports differentiates between heavy and moderate drinking, stating that heavy drinking is consistently correlated with weight gain, while light-to-moderate intake is not.

The Dietary Guidelines for Americans define excessive drinking as:

Four or more drinks per day for women.

Five or more drinks per day for men.

Eight or more drinks per week for women.

15 or more drinks per week for men.

Binge drinking, which is categorized as four or more drinks in two hours for women or five or more drinks in two hours for men.

Liquor vs. Beer

According to a 2018 Gallup poll, beer is the preferred alcoholic beverage in the United States. A total of 42 percent of Americans in the poll preferred beer, compared to 19 percent who preferred to drink liquor.

The same poll showed that since 1992, beer has consistently been the preferred beverage, with just one year's exception. In 2005, beer was preferred by only 36 percent of people. That year, wine was the preferred alcoholic beverage in the U.S., with a narrow preference of 39 percent.

Whisky's Popularity in America

Liquor has never been as popular as beer or wine. Its highest rating was 26 percent, in 2017 (compared to wine at 30 percent and beer at 40 percent).

The spirit of choice across America is whiskey, and the most popular brands are Jack Daniel's, Crown Royal, Fireball or Jameson. Although classified as whiskey, these are different beverages: Jack Daniel's is a Tennessee whiskey; Crown Royal is a Canadian whisky; Fireball is a sweetened, cinnamon-flavored Canadian whisky; and Jameson is an Irish whiskey. (Both spellings are correct: Generally, Scotch is spelled whisky, while bourbons and Irish varieties add the "e" for whiskey.)

Alcohol in Beer vs. Whisky

It's unsurprising that beer and whiskey are some of the most popular beverages in the United States, given the amount of varieties of both.

Most stores have many types of beer readily available, such as nonalcoholic beer, light beer, Belgian, India pale ale and stout. As mentioned, whiskey can come in various forms, like bourbon whiskey, Scotch whisky, Irish whiskey and whiskey-based liqueurs.

While most beers have around 5 percent alcohol content, they can have an alcohol by volume (ABV) as high as 67.5 percent. Whiskies typically have an ABV around 40 to 60 percent, although the strongest whiskey has a 92 percent ABV.

Calorie Consumption and Beverages

According to the Dietary Guidelines for Americans, about 20 percent of the total calories people consume come from beverages. This includes both alcoholic and nonalcoholic beverages.

Of course, mixed drinks contain calories that come from both alcohol and other ingredients. With no other ingredients, most drinks have 14 grams of pure alcohol, which is equal to 98 calories, from a single shot (1.5 ounces) of liquor.

Calories in Liquor vs. Beer

Pure spirits usually have no additional ingredients. This means that the calories in whiskey versus vodka or gin or tequila are typically the same, unlike the calories in whiskey versus beer. A standard 12-ounce serving of 5 percent ABV beer usually has around 150 calories, so there are less calories in whisky compared to beer per serving of alcohol.

Although one serving of liquor typically has less calories than one beer, the amount of calories your alcoholic beverage has can vary, depending on its other ingredients. Many people dilute spirits with sweetened mixers. A 7-ounce mixed drink, like rum and Coke, would likely have about the same amount of calories (155 calories) as a 12-ounce beer.

Calories in Whiskey vs. Beer

The way alcoholic beverages are produced can also influence their calories. For example, there are many different low-calorie beers, many of which contain about 100 calories per beer — and low-calorie beers can have as few as 55 calories per beer. However, the lower the calories of the beer, the lower its alcohol content, in general.

Unlike beer, spirits like whisky don't come in low-calorie versions. If anything, the less alcohol a whisky has, the more calories it is likely to have. This is because low ABV whiskies, like 33 ABV Fireball, typically have added ingredients and sugars. Most whiskies contain 98 calories per serving, but a flavored, sweetened whisky like Fireball has 108 calories per serving.

If you're watching your weight, you should stay away from flavored liquors to avoid the added sugars.

Read more: The 13 Worst Alcoholic Drinks Sure to Derail Your Diet

Servings for Alcoholic Beverages

The Dietary Guidelines for Americans considers one alcoholic drink to be the equivalent of 14 grams (0.6 fluid ounces) of pure alcohol. If you're comparing beer versus liquor, this means two different things: For liquor, 1.5 fluid ounces of an 80-proof distilled spirit (which is 40 percent alcohol), is considered one alcoholic drink. For beer, one alcoholic drink is the equivalent of 12 fluid ounces with an ABV of 5 percent.

Because drinking in moderation is not correlated with weight gain, unlike heavy drinking, you should make sure you're aware of how much alcohol you're consuming.

Calculating Alcoholic Drink Equivalents

Both liquors and beers are available in a variety of different ABV percentages. To calculate alcohol drink equivalents, multiply the amount of beverage in ounces by the percentage of alcohol. Then, divide by 0.6 ounces of alcohol. For a standard 5 percent beer, such a calculation would look like:

(12 fluid ounces of beer x 0.05)/0.6 fluid ounces = 1 drink equivalent

A larger serving (16 fluid ounces) of the same percentage of beer would consequently be more than one drink:

(16 fluid ounces of beer x 0.05)/0.06 fluid ounces = 1.3 drink equivalents

