Beer contains alchohol, and there are about 7 calories per gram of alcohol, compared to 4 calories for carbohydrates or protein. Fat has about 9 calories per gram.
Beer is low in sugar.
Alcohol can cause blood sugar levels to drop more rapidly. That can stimulate your appetite, and disrupt your ability to tell when you've had enough to eat. This can also create fatigue and your energy level will suffer.
Beer is a source of soluble fiber which is derived from the cell walls of malted barley. A liter of beer contains an average of 20% of the recommended daily intake of fiber and some beers can provide up to 60%. As well as aiding healthy bowel function, this has a further benefit by slowing down the digestion and absorption of food and reducing cholesterol levels, which may help to reduce the risk of heart disease. Beer itself has no cholesterol.
Because alcohol interferes with the body's absorption of vitamins and minerals, it can lessen the body's ability to burn stored fat. Calories from alcohol may go right to your stomach. Also, alcohol is detoxified by the liver. In the process of metabolizing excess quantities of alcohol, the liver swells and may itself become filled with fat. All these factors contribute to what is known as a "beer belly."
One 12-ounce serving of "regular" (150 calories) beer per night adds more than 1,000 calories a week to a diet, and that works out to an extra 15 pounds per year. One light beer per night adds 10 pounds.
A 5-foot-9, 160-pound, 30-year-old man must walk only about 40 minutes at 3 miles per hour (moderate pace) to burn 150 calories.
Moderate levels of consumption of beer have been shown to reduce stress and the chances of heart disease.
Alcohol can impair your judgment, causing you to drink more than you should. To top it off, many people eat high-calorie, high-sodium snacks when they drink.
Beer contains significant amounts of magnesium, selenium, potassium, phosphorus, biotin, and is chock full of B vitamins.
Alcohol destroys Vitamin C and Vitamin B complex. Drinking beer that has not filtered out the Vitamin B (such as English "real ale," many microbrewed beers and homebrew) will help combat the effects of alcohol — most notably a hangover.