| Protein | Fat | Carbohydrate | |
| Almonds | 21.4 | 54.4 | 13.8 |
| Peanuts | 29.8 | 46.5 | 17.1 |
| Filberts | 16.5 | 64.0 | 11.7 |
| Hickory | 15.4 | 67.4 | 11.4 |
| Pine nut | 33.9 | 48.2 | 6.5 |
| Walnut | 18.2 | 60.7 | 13.7 |
| Pecan | 12.0 | 70.7 | 18.5 |
| Butternut | 27.9 | 61.2 | 5.7 |
| Beechnut | 21.8 | 49.9 | 13.8 |
| Chestnut | 10.7 | 7.8 | 70.1 |
| —— | —— | —— | |
| Average | 20.76 | 53.08 | 18.23 |
Meat (round steaks) gives 19.8 per cent. of protein and 15.6 per cent. of fat, with no carbohydrate. A pound of average nuts contains the equivalent of a pound of beefsteak, and in addition, nearly half a pound of butter and a third of a loaf of bread. A nut is, in fact, a sort of vegetable meat. Its composition is much the same as that of fat meat, only it is in much more concentrated form.
There can be no doubt that the nut is a highly concentrated food. The next question naturally is, can the body utilize the energy stored in nuts as readily as that supplied by meat products, for example.
The notion that nuts are difficult of digestion has really no foundation in fact. The idea is probably the natural outgrowth of the custom of eating nuts at the close of a meal when an abundance, more likely a super-abundance, of highly nutritious foods has already been eaten, and the equally injurious custom of eating nuts between meals. Neglect of thorough mastication must also be mentioned as a possible cause of indigestion following the use of nuts. Nuts are generally eaten dry and have a firm hard flesh which requires thorough use of the organs of mastication to prepare them for the action of the several digestive juices. Experiments made in Germany showed that nuts are not digested at all, but pass through the alimentary canal like foreign bodies unless reduced to a smooth paste before swallowing. Particles of nuts the size of small seeds wholly escaped digestion.
Having been for more than fifty years actively interested in promoting the use of nuts as a staple food, I have given considerable thought and study to their dietetic value and have made many experiments. About twenty-five years ago it occurred to me that one of the above objections to the extensive dietetic use of nuts might be overcome by mechanical preparation of the nut before serving so as to reduce it to a smooth paste and thus insure the preparation for digestion which the average eater is prone to neglect. My first experiments were with the peanut. The result was a product which I called peanut butter. I was much surprised at the readiness with which the product sprang into public favor. Several years ago I was informed by a wholesale grocer of Chicago that the firm's sales of peanut butter amounted on an average to a carload a week. I think it is safe to estimate that not less than one thousand carloads of this product are annually consumed in this country. The increased demand for peanuts for making peanut butter led to the development of "corners" in the peanut market, and more than doubled the price of the shelled nuts and to a marked degree influenced the annual production. The nut butter idea also caught on in England.
I am citing my experience with the peanut not for the purpose of recommending this product, for I am obliged to confess that I was soon compelled to abandon the use of peanut butter prepared from roasted nuts for the reason that the process of roasting renders the nut indigestible to such a degree that it was not adapted to the use of invalids. I only mention the circumstance as an illustration of the readiness with which the public accepts a new dietetic idea when it happens to strike the popular fancy.
Ways may be found to render the use of nuts practical by adapting them to our culinary and dietetic customs and to overcome the popular objections to their use by a widespread and efficient campaign of education. Other nuts, when crushed, made most delicious "butters," as easily digestible as cream, since they did not require roasting. I later found ways for preparing the peanut without roasting.
The fats of nuts, their chief food principle, are the most digestible of all forms of fat. Having a low melting point they are far more digestible than most animal fats. Hippocrates noted that the stearin of eels was difficult of digestion. The indigestibility of beef and mutton fat has long been recognized. The fat of nuts much more closely resembles human fat than do fats of the sort mentioned. The importance of this will be appreciated when attention is called to the fact that fats entering the body do not undergo the transformation changes which take place in other foodstuffs; for example, protein in the process of digestion is broken into its ultimate molecular units. Starch is transformed into sugar which serves as fuel to the body, but fats are so slightly modified in the process of digestion and absorption that after reaching the blood and the tissues they are reconstructed into the original form in which they are eaten, that is, beef fat is deposited in the tissues as beef fat without undergoing any chemical change whatever; mutton fat is deposited as mutton fat; lard as pig fat, etc. When the body makes its own fat from starch or sugar, the natural source of this tissue element, the product formed is sui generis and must be better adapted to the body uses than the animal fat which was sui generis to a pig, a sheep or a goat. It is certainly a pleasant thought that one who rounds out his figure with the luscious fatness of nuts may felicitate himself upon the fact that his tissues are participating in the sweetness of the nut rather than the relic of the sty and the shambles.
It is also worthy of note that the fat of nuts exists in a finely divided state, and that in the chewing of nuts a fine emulsion is produced so that nut fats enter the stomach in a form best adapted for prompt digestion.
Another question which will naturally arise is this: if nuts are to be granted the place of a staple in our list of food supplies will it be safe to accept them as a substitute for flesh foods?