+-------------------------------++-------------------------------------+ | Food. || Flesh. | +-------+-----------------------++--------------+----------------------+ | Meat. | Non-nitrogenous Food. || Metabolized. | Balance of the Body. | +-------+-----------------------++--------------+----------------------+ | grams | grams || grams | grams | | 500 | 250 Fat || 558 | -58 | | 500 | 300 Sugar || 466 | +34 | | 500 | 200 Sugar || 505 | -5 | | 800 | 250 Starch || 745 | +55 | | 800 | 200 Fat || 773 | +27 | | 2000 | 200–300 Starch || 1792 | +208 | | 2000 | 250 Fat || 1883 | +117 | +-------+-----------------------++--------------+----------------------+ In considering the results of this experiment, it must be remembered that the calorific or fuel value of fat as compared with carbohydrate is as 9.3 : 4.1; in other words, fats have a fuel value of more than twice that of carbohydrates. In spite of this fact, it is clearly evident that carbohydrates as a class--for the different sugars and starches act alike in this respect--are far more efficient than fats in saving proteid. Thus, with an income of 500 grams of meat and 250 grams of fat, the body of the animal lost 58 grams of proteid, while with a like amount of meat and 300 grams of sugar the body not only saved the 58 grams, but in addition stored 34 grams of proteid, showing a plus balance to that extent. The sparing of proteid by carbohydrate amounts on an average, according to Voit, to 9 per cent--in the highest cases to 15 per cent--of the proteid given, while the saving produced by fat averages only 7 per cent. Further, increasing quantities of carbohydrates in the food diminish the rate of proteid metabolism much more regularly and constantly than increasing quantities of fat. We may attribute this difference in action, in a measure at least, to the greater ease in oxidation and utilization of the carbohydrate. In any event, starches and sugars are most valuable adjuncts to the daily diet, because of this marked proteid-saving power, while their fuel value adds just so much to the total energy intake.