| Japanese prisoners | 1 | 36 | 6 | 360 | 1725 |
| Inmates of home for aged--Germany | 1 | 85 | 43 | 322 | 2097 |
| Inmates of hospitals for insane--America | 49 | 80 | 86 | 353 | 2590 |
| | | | | | |
| _Persons in Destitute Circumstances._| | | | | |
| Prussian working people | 13 | 63 | 43 | 372 | 2215 |
| Italian mechanics | 5 | 70 | 36 | 384 | 2225 |
| American working-men's families | 11 | 69 | 75 | 263 | 2085 |
+------------------------------------------+--------+------+------+--------+---------+

The heats of combustion of all the fats in an ordinary mixed diet would
average about 9.40 calories per gram, but as only 95% of the fat would
be available to the body, the fuel value per gram would be (9.40 X 0.95
=) 8.93 calories. Similarly, the average heat of combustion of
carbohydrates of the diet would be about 4.15 calories per gram, and as
97% of the total quantity is available to the body, the fuel value per
gram would be 4.03. (It is commonly assumed that the resorbed fats and
carbohydrates are completely oxidized in the body.) The heats of
combustion of all the kinds of protein in the diet would average about
5.65 calories per gram. Since about 92% of the total protein would be
available to the body, the potential energy of the available protein
would be equivalent to (5.65 X 0.92 =) 5.20 calories; but as the
available protein is not completely oxidized allowance must be made for
the potential energy of the incompletely oxidized residue. This is
estimated as equivalent to 1.15 calories for the 0.92 gram of available
protein; hence, the fuel value of the total protein is (5.20 - 1.15 =)
4.05 calories per gram. Nutrients of the same class, but from different
food materials, vary both in digestibility and in heat of combustion,
and hence in fuel value. These factors are therefore not so applicable
to the nutrients of the separate articles in a diet as to those of the
diet as a whole.

6. _Food Consumption._--Much information regarding the food consumption
of people in various circumstances in different parts of the world has
accumulated during the past twenty years, as a result of studies of
actual dietaries in