The question whether alcohol is a food has been much debated. Like sugar, to which it is chemically allied, it is capable of furnishing energy by its oxidation; the alcohol in a pint of Guiness' stout, for instance, is equivalent to 230 calories. Now there can be no doubt that alcohol undergoes oxidation in the tissues : taken in moderate quantities the whole of it suffers oxidation, though taken in larger, some, no doubt, escapes unoxidized with the breath and the urine. It is therefore evident that ingested alcohol furnishes some energy to the organism. Whether this energy is manifested entirely as heat, or whether some of it may, like that evoked by sugar, be converted by the muscles into "work," we do not know. But in deciding the question whether alcohol is to be regarded as a food, it has to be remembered that the actual amount of energy yielded by permissible doses of alcohol is very small - no more than can be furnished by a quite insignificant amount of starch, sugar, or fat; further, that alcohol promotes the dissipation of heat from the body, a loss which must be set against the heat gain resulting from its oxidation; and, finally, that there is evidence to show that even if alcohol is capable of furnishing a spurt of energy for muscular work, its administration far from enhancing the capacity of the muscles for sustained activity tends, in point of fact, to lower it.
On the other hand, there can be no question that the consumption of alcohol promotes fat formation, and diminishes the amount of food needful to sustain the body weight. Thus it will often be found that when a person accustomed to alcohol suddenly leaves it off, he eats more. Naturally, malt liquors are fattening owing to the large amount of saccharides they contain, but spirits may sometimes be observed to produce the same effect. We have seen an abstainer rapidly increase in weight after adding to his dietary a daily allowance of two glasses of whisky. It is probable, however, that when alcohol is taken in physiological quantities its influence in augmenting body weight or in curtailing the needful amount of starch, sugar, fat, or protein, is very small.
To sum up : the consumption of alcohol leads to an increase in the production of heat, which, however, is met by a corresponding, or even greater, heat loss; it may possibly furnish energy for muscular contraction, but, on the other hand, it diminishes the capacity for sustained muscular work; it promotes the laying-on of fat, and diminishes the amount of food needful to sustain the body weight, but when taken in physiological quantities its effect in these two directions is, under normal conditions at least, exceedingly small.
There is yet one other consideration. It has to be remembered that alcohol differs from all other foods in the rapidity with which it is absorbed, in that it undergoes immediate absorption without requiring any preliminary digestion.
Alcohol has a strong affinity for oxygen, and consequently its ingestion checks the process of oxidation within the body, either of the food-stuffs before they have been built up into protoplasm, or of the protoplasm itself. It is probably largely on this account that it promotes the lay-ing-on of fat and when taken in excess leads to widespread fatty degeneration. It is worthy of note that in this respect alcohol acts like some other vegetable poisons, such, for instance, as certain of the diphtheritic toxins, which also, curiously, further resemble alcohol in their tendency to set up neuritis. The fatty degeneration of chronic alcoholism is perhaps most characteristically seen in the liver and the heart. The fatty heart of chronic alcoholism is, according to Dr. Wynn Wescott, the well-known coroner, the most common cause of sudden death.