There are two reasons that alchohol may impede weight loss. These are clinically based explainations.
The first below is from:
Does alcohol impact your weight?
Your body has a set number of calories necessary that must be consumed to maintain your weight. This need is based on your height, weight, age, gender, and activity level. When you consume more calories than your body needs, you will gain weight. Alcohol provides many calories in a small volume and can end up being a source of unwanted extra calories and weight gain. One study showed a 20% increase in calories consumed at a meal when alcohol was consumed before the meal. There was a total caloric increase of 33% when the calories from the alcohol were added. These additional calories can very easily contribute to weight gain over a short amount of time.
Studies have shown that in the short term, alcohol stimulates food intake and can also increase subjective feelings of hunger. Other studies have shown that the stimulatory effects of alcohol on food intake are controlled by hormonal regulation of satiety and satiation, such as the hormone leptin. Regardless of the cause, the outcome is the same; people consume more food when they have consumed alcohol.
Regulating your calorie consumption is the key to successful weight loss and maintenance. A balanced diet will assist with curbing your hunger and providing the necessary nutrients for health and wellness. Alcohol is not considered a necessary component in a healthy diet. Instead, it provides a lot of calories and negatively impacts many aspects of your health. If you choose to consume alcohol, you will need to limit the quantity and frequency that you do so. You will also have to count the calories from alcohol in any diet plan. You can limit calories in your drink by choosing those with less alcohol and a limited amount of sweetened beverages. By using flavored seltzers or water, you will save many calories.
Here are the calorie contents for some common alcoholic drinks:
Beer, lite, 12 oz.
Beer, regular, 12 oz.
Frozen daiquiri, 4 oz.
Gin, 1.5 oz.
Mai tai, 4 oz.
Margarita, 4 oz.
Rum, 1.5 oz.
Vodka, 1.5 oz.
Whiskey, 1.5 oz.
Wine spritzer, 4 oz.
Wine, dessert, sweet, 4 oz.
You can look up other drinks at http://www.fitday.com/webfit/calories/calories_93.html. Here are some tips for calorie reduction.
Have one nonalcoholic drink in between each alcoholic drink.
Select light versions whenever possible. "Light" means fewer calories, but these products are not calorie- or alcohol-free, so you will still need to limit your intake.
Keep water available to quench your thirst while you drink alcoholic beverages.
This second article may talk to another one of the keys why alchohol causes delayed weight gain. It is because it interferes with fat metabolism. For your reference:
alchohol= 7 cal/gr
Fat= 9 calories/gr
Carb= 4 cal/gr
protein= 4 cal/gr
Most alchoholic drinks calories do not come from the carbs they come from the alchohol itself.
Alcoholic beverages all contain calories, and most of the calories come from the alcohol. (We are speaking about straight spirits, wine, or beer—not mixed drinks made with added ingredients, which can bring calories to, well, staggering levels
Alcohol is not a carbohydrate.
**Your body processes alcohol first, before fat, protein, or carbs. Thus drinking slows down the burning of fat. This could account for the weight gain seen in some studies.
Hard liquor is distilled and thus contains no carbohydrates. The current “Zero Carb” campaign for vodka and whiskey is baloney and may encourage mindless consumption. It’s like bragging that a candy bar is “cholesterol-free.”
When grapes are made into wine, most of the fruit sugars (carbs) convert to alcohol, but a few carbs remain. A 5-ounce glass of wine typically contains 110 calories, 5 grams of carbohydrates, and about 13 grams of alcohol (which accounts for 91 of the calories). A 5-ounce glass of wine supplies roughly the same amount of alcohol and number of calories as a 12-ounce light beer or 1.5 ounces of 80-proof spirits.
Beer, too, contains carbohydrates. The new low-carb beers are not new at all, though this type of beer does indeed have fewer carbs. Low-carb beers are simply the old light beers with a new label and ad campaign. The old Miller Lite has 96 calories and 3.2 grams of carbs in 12 ounces. The “low-carb” Michelob Ultra has 96 calories and 2.6 grams of carbs. Coors Lite has 102 calories and 5 grams of carbs. The differences are tiny—hardly worth mentioning. In contrast, a regular beer has 13 grams of carbs and 150 calories.
What it all boils down to
In spite of the strong implication that “low-carb” somehow means low-calorie, and that low-carb foods in general can help you lose weight—or, indeed, that they are “health foods”—there’s no evidence this is so, and particularly not when it comes to beer, wine, and liquor. Alcoholic beverages have calories because alcohol has a lot of calories—not because of carbs. The impli-cation that low-carb beers and wine or carb-free spirits are a boon on a weight-loss program is simply deceptive advertising.
Hope this helps.