e body but not requiring digestion.

Just what function each one of these four groups plays in the nutrition
of the human body is not definitely understood, but it seems that the
proteids are particularly useful in building up cell tissue, that the
carbohydrates are particularly useful in providing for muscular energy,
that the fats are particularly useful in keeping up the normal warmth
rather more by laying on a blanket of fat over the bones than in
actually consuming the food in the creation of heat. These statements
are not absolute, since experiments have shown that some tissue-building
can go on even if proteids are rigorously excluded from the diet, and on
the other hand that muscular work, while accompanied by a large
consumption of carbohydrates in the body, may come from proteids
entirely. This may explain why men can live and even do a reasonable
amount of work eating meat and fat altogether, as in the Arctic regions,
or dry bread and fruit in other regions, the above facts being
complicated by the influence of muscular exercise on the activity of the
digestive system.

No principle of hygiene is better established than that men undergoing
hard physical exercise need and will take care of a larger amount of
coarse food than those occupied in sedentary work. In cold weather what
is required is not really more fat as food, but more food. It has been
found that there is a limit to the amount of meat food which the body
can absorb, and, further, that the excess is not easily disposed of, as
with starchy food, and tends to load up the liver and other organs with
the waste products, resulting in general disturbances of the whole body.
It is commonly known, for instance, that high-livers, as they are
called, are likely to be troubled with diseases like indigestion,
rheumatism, or gout,--diseases which are the result of overburdening
those organs just mentioned.

_Balanced rations._

TABLE XVI

==================================+======================================
| WEIGHT IN GRAMMES
CONDITION +-----------+-----------+--------------
| Proteid | Fat | Carbohydrates
----------------------------------+-----------+-----------+--------------
Child up to 1-1/2 years (average) | 0.71-1.27 | 1.06-1.59 | 2.12-3.18
Child from 6 to 15 years | | |
(average) |