Meat is composed largely of muscle fiber and contains connective tissue and fat. It has been estimated that beef contains one-third nutritive material, the other two-thirds being water and bone. Fat meat contains less nitrogenous material and less water than lean meat.
Lean meat is almost entirely digested in the stomach by the gastric juice, which changes it into peptone. It is needless to say that it should be thoroughly masticated, that the gastric juice may promptly act on it. If any part passes into the intestine undigested, the process is continued by the trypsin of the pancreatic juice.
The peptone is absorbed and carried by the blood and lymph to all tissues of the body, where it is used for growth and repair. As stated under “Heat and Energy,” any excess of protein above that needed for growth and repair is oxidized if sufficient oxygen is breathed, yielding energy and heat, and the waste is eliminated through the kidneys and the bile.
For purposes of comparison, one pound of beef has been said to equal in nutritive value, two and one-half pints or five glasses of milk, one-half pound (two-thirds of an ordinary baker’s loaf) of bread, and three eggs. However, these values vary.
TABLE IV
Animal Foods
| FOOD MATERIALS | Water per cent. | Protein per cent. | Fat per cent. | Carbohydrates per cent. | Ash per cent. | Fuel Value per pound Calories |
| Beef, Fresh | 54.0 | 17.0 | 19.0 | .... | 0.7 | 1105 |
| Flank | 54.0 | 17.0 | 19.0 | .... | 0.7 | 1105 |
| Porterhouse | 52.4 | 19.1 | 17.9 | .... | 0.8 | 1100 |
| Sirloin steak | 54.0 | 16.5 | 16.1 | .... | 0.9 | 975 |
| Round | 60.7 | 19.0 | 12.8 | .... | 1.0 | 890 |
| Rump | 45.0 | 13.8 | 20.2 | .... | 0.7 | 1090 |
| Corned beef | 49.2 | 14.3 | 23.8 | .... | 4.6 | 1245 |
| Veal: | ||||||
| Leg cutlets | 68.3 | 20.1 | 7.5 | .... | 1.0 | 695 |
| Fore quarter | 54.2 | 15.1 | 6.0 | .... | 0.7 | 535 |
| Mutton: | ||||||
| Leg, hind | 51.2 | 15.1 | 14.7 | .... | 0.8 | 890 |
| Loin chops | 42.0 | 13.5 | 28.3 | .... | 0.7 | 1415 |
| Lamb | 49.2 | 15.6 | 16.3 | .... | 0.85 | 967 |
| Ham: | ||||||
| Loin chops | 41.8 | 13.4 | 24.2 | .... | 0.8 | 1245 |
| Ham, smoked | 34.8 | 14.2 | 33.4 | .... | 4.2 | 1635 |
| Sausage: | ||||||
| Frankfurter | 57.2 | 19.6 | 18.6 | 1.1 | 3.4 | 1155 |
| Poultry: | ||||||
| Fowls | 47.1 | 13.7 | 12.3 | .... | 0.7 | 765 |
| Goose | 38.5 | 13.4 | 29.8 | .... | 0.7 | 1475 |
| Turkey | 42.4 | 16.1 | 18.4 | .... | 0.8 | 1060 |
| Animal Viscera: | ||||||
| Liver (sheep) | 61.2 | 23.1 | 9.0 | 5.0 | .... | .... |
| Sweetbreads | 70.9 | 16.8 | 12.1 | .... | 1.6 | .... |
| Tongue, smoked and salted | 35.7 | 24.3 | 31.6 | .... | 8.5 | .... |
| Brain: | 80.6 | 8.8 | 9.3 | .... | 1.1 | .... |
| Fresh Fish: | ||||||
| Bass large-mouthed | ||||||
| Black, dressed | 41.9 | 10.3 | 0.5 | .... | 0.6 | 215 |
| Cod steaks | 72.4 | 16.9 | 0.5 | .... | 1.0 | 335 |
| Shad roe | 71.2 | 23.4 | 3.8 | .... | 1.6 | 595 |
| Whitefish, dressed | 46.1 | 10.2 | 1.3 | .... | 0.7 | 245 |
| Preserved Fish: | ||||||
| Halibut, salted, smoked and dried | 46.0 | 19.1 | 14.0 | .. | 1.9 | 945 |
| Sardines, canned | 53.6 | 24.0 | 12.1 | ... | . 5.3 | 955 |
| Salmon, canned | 59.3 | 19.3 | 15.3 | ... | . 1.2 | 1005 |
| Mollusks: | ||||||
| Oysters, solid | 88.3 | 6.1 | 1.4 | 3.3 | 0.9 | 235 |
| Round clams removed from shell | 80.8 | 10.6 | 1.1 | 5.1 | 2.3 | 340 |
| Mussels | 42.7 | 4.4 | 0.5 | 2.1 | 1.0 | 140 |
| Crustaceans: | ||||||
| Lobster, in shell | 31.1 | 5.5 | 0.7 | .... | 0.6 | 130 |
| Crab, in shell | 34.1 | 7.3 | 0.9 | 0.5 | 1.4 | 185 |
| Shrimp, canned | 70.8 | 25.4 | 1.0 | 0.2 | 2.6 | 520 |
| Terrapin, turtle, etc. | 17.4 | 4.2 | 0.7 | ... | 0.2 | 105 |
The amount of fat in meat varies from two to forty per cent., according to the animal and to its condition at the time of killing.
The best meats are from young animals which have been kept fat and have not been subjected to any work to toughen the muscles.
It is possible to combine the fat and the lean of meat so as to meet the requirements of the body without waste. About ninety-seven per cent. of meat is assimilated by the system, while a large part of the vegetable matter consumed is excreted as refuse.
The compounds contained in animal foods are much like those of the body, therefore they require comparatively little digestion to prepare them for assimilation—this work having been done by the animal—while the vegetable compounds require much change by the digestive system before they can be used in the body.