of excretion. It may also lead to the accumulation of burdensome fat and
of harmful wastes. On the other hand, the taking of too little food
impoverishes the blood and weakens the entire body. As a rule, however,
more people eat too much than too little, and to quit eating before the
appetite is fully satisfied is with many persons a necessary precaution.
The power of self-control, valuable in all phases of life, is
indispensable in the avoidance of overeating.

*Frequency of Taking Food.*—Eating between meals is manifestly an
unhealthful practice. The question has also been raised as to whether the
common habit of eating three times a day is best suited to all classes of
people. Many people of weak digestive organs have been benefited by the
plan of two meals a day, while others adopt the plan of eating one heavy
meal and two light ones. Either plan gives the organs of digestion more
time to rest and diminishes the liability of overeating. On the other
hand, those doing heavy muscular work can hardly derive the energy which
they need from less than three good meals a day. Though no definite rule
can be laid down, there is involved a hygienic principle which all should
follow: _Meals should not overlap_. The stomach should be free from food
taken at a previous meal before more is introduced into it. When this
principle is not observed, material ferments in the stomach, causing
indigestion and other disorders. It should be noted, however, that the
overlapping may be due to overeating as well as to eating too frequently.

*Dangers from Impure Food.*—Food is frequently the carrier of disease
germs and for this reason requires close inspection (page 128). Typhoid
fever, a most dangerous disease, is usually contracted through either
impure food or impure water (Chapter XXIII). One safeguard against disease
germs, as stated above, is thorough cooking. Too much care cannot be
exercised with reference to the water for drinking purposes. Water which