There are on record certain experiments which appear to indicate the necessity of a large proportion of proteid, especially when the diet has been of vegetable origin.  These experiments are inconclusive, because the subject has been accustomed to an ordinary flesh diet, perhaps also to alcoholic drinks.  The change to a comparatively non-stimulating diet cannot be made, and the digestive organs expected to adapt themselves in a few days.  Perhaps not even a month or a year would suffice, for some people, and yet that same diet would suit others.  In some experiments the food has not been appetising, the subject has even taken it with reluctance or even loathing; an excess of some food has been eaten which no vegetarian or anybody else would think of using in a practical dietary.

Sometimes persons on changing from an ordinary flesh dietary, lose weight and strength.  Generally, it is found that they have done little more than discontinue the flesh, without substituting suitable foods.  Authorities think it is from a deficiency of proteid, and recommend an addition of such foods as pulse, wheatmeal, oatmeal, eggs, milk, cheese, and such as a reference to the table of analyses, show a low nutrient ratio figure.  This may also be due to an insufficiency of food eaten, owing to the comparatively insipid character of the food and want of appetite.  In making a change to a vegetarian diet, such foods had better be taken that are rather rich in proteid, and that approximate somewhat in their flavour and manner of cooking to that used previously.  A further change to a simpler diet can afterwards gradually be made, according to conviction, tastes and bodily adaptability.  It must not be expected that a change, even an ultimately very advantageous one, will always meet with an immediate and proper response from digestive and assimilative organs which have been accustomed for many years, perhaps by inheritance for generations, to another manner of living.  There are several preparations produced from centrifugalised milk—­that is milk from which the butter fat has been removed, which consist chiefly of proteid.  These have a value in increasing the proteid contents of foods which may be thought deficient.  The addition of these manufactured products appear unnecessary, as most of our food contains an abundance of proteid, and we can easily limit the quantity or avoid altogether those that are thought defective.

The later apologists for a flesh diet have had to admit that it is not a physiological necessity; but they have attempted to justify its use by a theory somewhat as follows.  It is admitted, that any excess of proteid over that necessary for its special province of producing tissue, is utilised as a force-producer, in a similar manner to the carbo-hydrates.  When the molecule is split up, and the carbon utilised, the nitrogen passes off in the form of urea by the kidneys.  The theory propounded is that at the moment the nitrogen portion is liberated, it in some