Some info I found on the subject:
Alcohol and weight loss are enemies, but an occasional drink can have a place in a healthy lifestyle. In fact, many experts note the health benefits of consuming a single drink per day, including a reduced risk for hypertension and high blood pressure. If, however, you are exceeding one drink daily, you might be sabotaging your weight loss plans.
Alcohol is metabolized differently than other foods and beverages. Under normal conditions, your body gets its energy from the calories in carbohydrates, fats and proteins that need to be slowly digested in the stomach—but not when alcohol is present. When alcohol is consumed, it gets special privileges and needs no digestion. The alcohol molecules diffuse through the stomach wall as soon as they arrive and can reach the brain and liver in minutes. This reaction is slightly slowed when there is also food in your system, but as soon as the mixed contents enter the small intestine, the alcohol grabs first place and is absorbed quickly. The alcohol then arrives at the liver for processing. The liver places all of its attention on the alcohol. Therefore, the carbohydrates (glucose) and dietary fats are just changed into body fat, waiting to be carried away for permanent fat storage in the body.
Alcohol is a diuretic, meaning that it causes water loss and dehydration. Along with this water loss you lose important minerals, such as magnesium, potassium, calcium and zinc. These minerals are vital to the maintenance of fluid balance, chemical reactions, and muscle contraction and relaxation.
Alcohol contains 7 calories per gram and offers NO nutritional value. It only adds empty calories to your diet. Why not spend your calorie budget on something healthier?
Alcohol affects your body in other negative ways. Drinking might help induce sleep, but the sleep you get isn't very deep. Ultimately, as a result, you get less rest. Alcohol can also increase the amount of acid that your stomach produces, causing your stomach lining to become inflamed. Over time, excessive alcohol use can lead to serious health problems, including stomach ulcers, liver disease, and heart troubles.
Alcohol lowers your inhibitions, which is detrimental to your diet plans. Alcohol actually stimulates your appetite. While you might be full from a comparable amount of calories from food, several drinks might not fill you up. On top of that, research shows that if you drink before or during a meal, both your inhibitions and willpower are reduced. In this state, you are more likely to overeat—especially greasy or fried foods—which can add to your waistline. To avoid this, wait to order that drink until you're done with your meal.
Many foods that accompany drinking (peanuts, pretzels, chips) are salty, which can make you thirsty, encouraging you to drink even more. To avoid overdrinking, sip on a glass of water in between each alcoholic beverage.
Skipping a meal to save your calories for drinks later is a bad idea. Many drinkers know they'll be having some alcohol later, whether going to a bar, party, or just kicking back at home. Knowing that drinking entails extra calories, it may be tempting to "bank" some calories by skipping a meal or two. This is a bad move. If you come to the bar hungry, you are even more likely to munch on the snacks, and drinking on an empty stomach enhances the negative effects of alcohol. If you're planning on drinking later, eat a healthy meal first. You'll feel fuller, which will stop you from overdrinking. If you are worried about a looming night out with friends, include an extra 30 minutes of exercise to balance your calories—instead of skipping a meal.
What are more important, calories or carbs? You might think that drinking liquor is more diet-friendly because it has no carbohydrates, while both wine and beer do contain carbs. But dieters need to watch calories, and liquor only has a few calories less than beer or wine. Plus, it is often mixed with other drinks, adding even more empty calories. Hard liquor contains around 100 calories per shot, so adding a mixer increases calories even more. If you are going to mix liquor with anything, opt for a diet or club soda, instead of fruit juice or regular soda. Sweeter drinks, whether liquor or wine, tend to have more sugar, and therefore more calories. In that respect, dry wines usually have fewer calories than sweet wines.
The list below breaks down the number of calories in typical alcoholic drinks. Compare some of your favorites to make a good choice next time you decide to indulge in a serving of alcohol.
5 oz. 100
5 oz. 130
12 oz. 105
12 oz. 140
12 oz. 170
3 oz. 165
3 oz. 205
Long Island iced tea
8 oz. 400
Gin & Tonic
8 oz. 175
Rum & Soda
8 oz. 180
8 oz. 200
4 oz. 200