nces, to build and repair muscular and other
tissues and to supply energy for muscular work, heat and other forms of
energy. The answer to the problem is sought in the data obtained in
dietary studies with considerable numbers of people, and in metabolism
experiments with individuals in which the income and expenditure of the
body are measured. From the information thus derived, different
investigators have proposed so-called dietary standards, such as are
shown in the table below, but unfortunately the experimental data are
still insufficient for entirely trustworthy figures of this sort; hence
the term "standard" as here used is misleading. The figures given are
not to be considered as exact and final as that would suggest; they are
merely tentative estimates of the average daily amounts of nutrients and
energy required. (It is to be especially noted that these are available
nutrients and fuel value rather than total nutrients and energy.) Some
of the values proposed by other investigators are slightly larger than
these, and others are decidedly smaller, but these are the ones that
have hitherto been most commonly accepted in Europe and America.

TABLE V.--_Standards for Dietaries. Available Nutrients and Energy
per Man per Day._

+---------------------------+---------+--------+---------+---------+
| | Protein.| Fat. | Carbo- | Fuel |
| | | |hydrates.| Value. |
+---------------------------+---------+--------+---------+---------+
| | | | | |
| _Voit's Standards._ |Grams.[9]| Grams. | Grams. |Calories.|
| Man at hard work | 133 | 95 | 437 | 3270 |
| Man at moderate work | 109 | 53 | 485 | 2965 |
| _Atwater's Standards._ | | | | |
| Man at very hard | | | | |
| muscular work | 161 | ..[10]| ..[10]| 5500 |
| Man at hard muscular work | 138 | .. | .. | 4150 |
| Man at moderately | | | | |
| active muscular work | 115 | .. | .. | 3400 |
| Man at light to moderate | | | | |
| muscular work | 103 | .. | .. | 3050 |
| Man at "sedentary" | | | |