Prof. Chittenden’s experiments of the foodstuffs actually required by three groups of men, one group of United States soldiers, a group from the Yale College athletic team, and a group of college professors, all showed that the men retained full strength, with a higher degree of physical and mental efficiency, when the body was not supplied with more protein than was liberated by metabolic activity, and when the quantity of carbonaceous food was regulated to the actual requirement to retain body heat and furnish energy. It may be well to call attention here to the fact that the food elements, called upon for work, are not from those foods just consumed or digested, but from those eaten a day or two previous, which have been assimilated in the muscular tissues. In selecting a diet, the individual must be considered as to age, sex and physical condition, also whether active in indoor or outdoor work, and whether he or she breathes deeply, so as to take plenty of fresh air into the lungs. The following tables, published through the courtesy of Dr. W. S. Hall, give the rations for different conditions. TABLE XI. _Rations for Different Conditions._ ———————————————————————————+—————————+————+—————————————+————————— |Proteins | |Carbohydrates|Energy in Conditions +————+————|Fats|—————+———————+ Calories |Low |High| | Low | High | ———————————————————————————+—————————+————+—————————————+————————— Man at light indoor work | 60| 100| 60| 390 | 450 | 2764 Man at light outdoor work | 60| 100| 100| 400 | 460 | 2940 Man at moderate outdoor | | | | | | work | 75| 125| 125| 450 | 500 | 3475 Man at hard outdoor work | 100| 150| 150| 500 | 550 | 4000 Man at very hard outdoor | | | | | | winter work | 125| 180| 200| 600 | 650 | 4592 U. S. Army rations | 64| 106| 280| 460 | 540 | 4896-5032 U. S. Navy rations | | 143| 292| 557 | | 5545 Football team (old regime) | | 181| 292| 557 | | 5697 College football team (new)| 125| 125| 125| 500 | | 3675 ———————————————————————————+—————————+————+—————————————+————————— TABLE XII. _Rations Varied for Sex and Age._