SEVERAL estimates of the food supply of Great Britain, in whole or in part, have been published in recent years. But in none of these has a computation been made of the “foodstuffs” contained in the food, or of the energy which it furnishes to the human body. Yet these are the only standards which apply to all foods, whether solid or liquid, and taken together constitute the only applicable test by which the supply can be properly gauged. Thus we can only say whether the supply is sufficient, excessive, or deficient, when we know the quantities of protein, carbohydrate, and fat, and the amount of energy it provides per day to the consumer. Further, it is only when we have this knowledge that we can intelligently proceed to substitute articles of diet for others which may have been cut off or rendered scarce from any cause.