It is clear from the calculations shown in the last column, that Cheddar cheese takes first rank among the foods compared as to fuel value. The estimate of food values in terms of calories may not completely express the value of that food to a particular individual. It is generally conceded that one great function of food is the production of energy and this function is probably more closely determined by the number of calories produced than in any other known way. Such calculation has become an essential factor in the preparation of dietaries. The calculation here given necessarily applies only to Cheddar cheese. By easy use of the last column, the caloric value of this cheese can be compared with that of any competing food and the relative economy determined, whatever the price asked. Another recent calculation with reference[146] to the same cheese follows: "One pound of American Cheddar cheese contains as much protein as-- 1.57 pounds of sirloin steak. 1.35 pounds of round steak. 1.89 pounds of fowl. 1.79 pounds of smoked ham. 1.81 pounds of fresh ham. "In order to judge the value of foods fairly not only the protein but the energy also must be compared. To supply energy cheese is one of the best of food products. On the basis of energy supplied, 1 pound of cheese equals-- 1.98 pounds of sirloin steak. 2.61 pounds of round steak. 2.52 pounds of fowl. 1.17 pounds of smoked ham. 1.29 pounds of fresh ham." All these discussions have applied to whole-milk Cheddar cheese. With minor reductions, much the same figures will hold for Swiss, Limburger, Brick, Munster, Edam. On the other hand, very little has been published until recently on the skimmed-milk cheeses. The food value lost in skimmed-milk has at times been enormous. Many households purchase milk by the bottle, use the top-milk as cream and lose a part of the remainder. Similarly creameries have wasted tons of skimmed-milk. The recovery of the protein of this milk for human food is both good economy and an important addition to the dietary. The United States Department of Agriculture has recently published the following: "Cottage cheese is richer in protein than most meats and is very much cheaper. Every pound contains more than three ounces of protein, the source of nitrogen for body building. It is a valuable source of energy also, though not so high as foods with more fat. It follows that its value in this respect can be greatly increased by serving it with cream, as is so commonly done." It is an open question whether the decline of cheese-making in America is not due to our failure to develop the use of skim and part-skim cheeses. The whole-milk cheeses are very rich in fat. Use of such cheese in quantity in connection with ordinary foods quickly leads to the ingestion of too much fat. The skimmed-milk cheeses are primarily protein food and as such substitutes for lean meat.