What you will read here in this article are my inferences and my comprehension of the research materials I have read. All I have done is to put together information from various sources, like a jig-saw puzzle to form a picture which I think is complete. Please note that I do not proclaim that alcohol has no ill effects on the body, I merely state that calories from alcohol do not lead to weight gain. Links to the various materials that I have read will be made available which you may read to verify. This article is open for debate and I will view it as a learning experience should there be a credible alternative stand and I am shown a different perspective.
In an argument or debate it is necessary that we define the topic we are going to discuss about and also set certain guidelines so as not to waver from the topic.
- The stand I am taking is that ‘Alcohol does not have any nutritional value and cannot be processed by the body as a source of fuel or be stored in our bodies as fat. In addition the process of metabolizing alcohol within our system consumes calories thereby making us expend energy already stored in the body’. 
- All claims must be backed by references from credible sources. A credible source is defined as a person or establishment that has scientific authority in the subject and has documented research findings. These would include Medical Doctors, Pharmacists and Chemists. It shall not include persons connected to an industry that manufacture supplements or equipment connected to physical fitness, or persons who are physical trainers or religious personalities as we must exercise caution to the fact that they could be financially motivated.
- There is always misunderstanding when debating over alcohol because many people use the word ‘alcohol’ to refer to any alcoholic drink. In my vocabulary the word ‘Alcohol’ refers to the chemical, an organic compound. For the sake of clarity let me define the way I see it and how I propose to debate over it.
- The form of alcohol we consume is called ethyl alcohol or ethanol. Ethanol cannot be consumed in its pure form as it is highly toxic. The alcoholic beverages we consume have anywhere between 5% and 45% of alcohol per volume of liquid.
- Consumable liquids that contain alcohol come in numerous forms. To name a few examples, some of the ones I’m familiar with are Whiskey, Arrack, Tequila, Vodka, Rum, Brandy, Beer, Wine etc. They can be broadly classified as Hard Liquor, Beer/Ales, Liqueur and Wine.
- Cocktails and Beverages containing alcohol are created by mixing the various forms of Liquor, Liqueur, Beer and Wine. They are almost always sweet.
Since alcohol can never be consumed in its pure form the alcoholic beverage we consume will have other substances in it that dilute the alcohol content. A large percentage of the substance that dilutes the alcohol in the beverage is water, however varying percentages of carbohydrates, fats, proteins and minerals may also be present. The total calorific count of an alcoholic beverage will vary depending on what the concoction contains. For instance 60ml of 80 proof whiskey will contain 24ml of alcohol and 36ml of malt water. If we were to dilute this drink with 270 ml of water, we would have a 330 ml drink whose calorific value will take into account the calorific value of the alcohol, and the carbohydrates present in the malt water. This calorific value will be different from the calorific value of 330 ml of draught beer with 5% concentration of alcohol which will contain lesser alcohol at 16.5ml and 323.5ml of carbonated barley water. Compare this with 330ml of an average cocktail and one must factor in the added sugar, coconut milk, cream, egg-yolk or whatever it is that one mixes to make that particular cocktail, when arriving at the calorific value.
This elaborate description was only for a proper understanding of the process of alcohol consumption because my argument continues to be on whether alcohol leads to weight gain and not what the drink does. A large amount of confusion arises because people keep making references to the calorific value of alcohol which is pegged at 7 calories per gram of Alcohol but what people don’t realize is that these calories cannot be utilized by the body. To further comprehend this it is necessary to understand how calorific values of substances are calculated. A calorie is the amount of energy, or heat required to raise the temperature of 1 gram of water by 1 degree Celsius. Calories are calculated by burning a substance and measuring the heat it generates, so saying that there are 7 calories per gram of Alcohol means that when 1 gram of alcohol is burned it rises the temperature of 1 gram of water by 7 degrees Celsius. Now calories can be calculated for any substance that has potential energy like wood, charcoal or petrol. 1 gram of petrol has a little more than 10 calories and herein lies my argument - Alcohol like petrol is a substance that has a calorific value but cannot be utilised by the body for its energy needs.
When a substance is ingested it is acted upon by the body in a process known as metabolism . Absorption of substances into our blood stream happen at various locations along the digestive tract depending of the substance consumed. Some are absorbed in the intestines after they are broke down in the stomach with the aid of acids, some in the stomach itself and some even through the lining tissue in the mouth. Alcohol is directly absorbed into the blood stream partly through the stomach and the rest through the intestines.
The main enzyme responsible for the metabolism of alcohol is ‘alcohol dehydrogenase’ (ADH). Though a small percentage of alcohol is excreted from the body through the kidneys and another small percentage is exhaled and expelled through the lungs (which is what the breath analyzer catches), a vast majority of it is broken down, metabolized into less toxic forms and expelled from the body by the liver. Since Alcohol cannot be stored by the body it takes priority in the energy consuming process of metabolism over all other substances to get metabolized first. ‘Alcohol dehydrogenase’ (ADH) breaks down alcohol into acetaldehyde and this is further metabolised by other enzymes into acetate and converted further into carbon dioxide and water. None of these metabolic by-products can be used by the body as fuel or as building blocks for our body and in short have no nutritional value. Therefore, if you add the processes together you will realise that our body would have spent energy metabolizing the alcohol a substance that contribute nothing to the energy needs with the end result being a deficit in calories. This explains why heavy alcoholics are always thin.
So why is there such a huge lobby of people suggesting that alcohol leads to an increase in weight? This is because it has been observed that a majority of the people who consume alcohol on a regular basis are overweight but the preachers of ‘alcohol is converted into fat’ are misinformed. Here is where alcohol also has to be studied for its impact on our body in the form of a drug.  In the case of alcohol as a drug there are many different types of effects on the human body, all depending on the quantity of alcohol consumed and in how much time. Not all these effects are bad. There are good effects which include the lowering of LDL, a bad form cholesterol which leads to thickening of arteries and heart attack. In a healthy body, the negative effects are all attributed to excessive alcohol intake.  The excess alcohol interferes with the liver’s numerous functions due to the priority given to it in metabolism. In turn, imbalances are created which can lead to hypoglycemia (low blood sugar), hyperuricemia (as in arthritis or gout), fatty liver (which may lead to hepatitis or cirrhosis), and hyperlipemia (build-up of fats sent to the bloodstream; which leads to heart problems).
It’s the livers role in maintaining the balance of blood sugar that is of interest to us in weight gain. Since the liver is responsible for maintaining blood sugar levels, the process of replenishing the depleted sugar in the blood gets affected when the liver is busy processing alcohol. The brain in turn realises the dip in sugar levels and prompts the body to crave for food, particularly starchy food even though sugar reserves are there in the body. Once the alcohol is removed from the body, the liver is presented with an overload of sugar which it promptly converts into fat.
To sum it up, the gain in weight observed among consumers of alcohol is a result of the effect alcohol has on the body as a drug where it reduces the body’s capacity to maintain a proper balance in blood sugar. The imbalance in blood sugar levels prompt the brain to send out signals, whereby we may consume more carbohydrates and those who heed to this demand by consuming sugary, starchy drinks or snacks will process all the excess sugar into fat when the alcohol wears off the body. In effect it would mean that those who can learn the proper balance of tweaking the amount of food ingested, when it is ingested and what is ingested during consumption of alcohol can also protect themselves from weight gain. My conclusion from all that has been read and understood is that metabolizing alcohol leads to a deficit in calories and that alcohol cannot contribute to the energy needs of the body nor can it be stored in the form of fat.
 The main food groups that our bodies require for functioning are Carbohydrates, Protein, Fat, Vitamins and Minerals. The first three, called nutrients can be processed by our bodies as fuel and as raw material for maintaining our bodies. Excess in any of the three nutrients can lead to the excess being stored within our bodies in the form of fat or muscle which can in times of need be reconverted into forms that provide energy.
 All substances are metabolized by the body except in the case of inert substances such as dietary fiber. Though dietary fiber is a complex form of carbohydrate, our bodies do not have the capacity to digest the substance. In addition, since the substance does not react with the body chemically it passes through the system till it is excreted in the feces. The body’s energy needs are met by the nutritious substances that we consume after it undergoes metabolism. Metabolism is a very complex energy consuming process but in a nutshell, it is a biochemical process where the body converts the digested or blood absorbed substance into a form that the body can handle. The body does this by using enzymes which are complex forms of proteins created by the body to act as catalysts in the process of metabolism. When this energy consuming process of metabolism involves nutritious substances the end result would be a gain in usable energy. The body after utilizing the required energy would store the excess. However, when the metabolic process involves innutritious substances like drugs the end result would be expense of energy without gain.
 A drug is defined as any substance that when introduced into a human body can alter normal functioning. We are all familiar with drugs prescribed by doctors and with recreational drugs most of which are banned but drugs can also come camouflaged in the form of cigarettes (Nicotine is the primary drug here), a cup of coffee (caffeine is the primary drug here) or as an alcoholic beverage (Alcohol would be the primary drug here). Dependency on Alcohol as a drug is referred to as alcoholism and the person dependant on Alcohol for his daily activities is referred to as an alcoholic.
 Excessive alcohol is subjective since it is dependent on various factors such as body weight, ethnic background, how much food has been consumed, how well hydrated the body is etc.
Alcohol, Calories & Weight - State University of New York, Potsdam
Macronutrients and energy balance - The American Journal of Clinical Nutrition;
Alcohol Metabolism – National Institute of Alcohol Abuse and Alcoholism
Skinny drinking - New Scientist magazine
Alcohol and Your Body - Brown University, Providence, Rhode Island