This section is from the book "Health Without Medicine. A Treatise On The Laws Of The Human System", by Larkin B. Coles. Also available from Amazon: Philosophy Of Health.
Time for digesting what is eaten, demands of every one who values health, a most serious consideration. Ignorance on this topic, and inattention to its importance even when understood, have involved thousands and millions in untold suffering and premature death. If it were possible so to impress the mind of community on this subject, that they would obey nature's laws, or rather the laws which the Great Author of nature has given to our digestive systems, we should sec a very obvious change taking place in the standard of general health. The larger portion of people have no rules for eating, but to eat, as they say, "when they are hungry;" having no regard to the time of eating, or to time for digesting; but like the short-fed beasts, take a little here and there, whenever and wherever they can get it. They think their own stomachs are a sufficient guide, in spite of facts and philosophy. Therefore, they eat whenever they take a notion. Their stomachs would perhaps guide them in the right way if a morbid action of those organs had never been induced by previous irregularities.
Three meals a day are sufficient for all classes of persons, under all circumstances, and of all ages. For persons having weak stomachs, and many persons of sedentary habits, two meals a day, rightly distanced, might be preferable. But no individual, whatever may be his age, his occupation, or his health, should take solid food more than three times in one day. No person can do more than this without transgressing nature's laws. The reasons for this rule will soon be given.
An argument against taking food at regular intervals is often attempted from the fact that many dumb animals have no regular times of eating; and it is urged that these animals have no other guide than the dictates of nature. In answer to this, it may be said, that the habits of dumb beasts, since the introduction of sin into the world, under the weight of which "the whole creation," or rather, as the original signifies, EVERY CREATURE, "groaneth, being burdened," are not always in exact accordance with nature's rules. For instance, cattle are put into a lean pasture; and they are unable to gather a full meal at once; they are obliged, perhaps, to graze all day long to obtain sufficient subsistence. In such cases, to allow intervals between meals, would be to undergo gradual starvation. But put dumb animals into full feed, and what do they do? They deliberately eat a full meal, and then cease eating till that meal is fully digested. Hence, the testimony taken from this source, when we make a fair test, is unequivocally and uniformly in favor of eating at intervals sufficient for digestion.
Eating at intervals sufficiently long to allow the full digestion of a meal before another is taken, is as truly essential to the good constitution and health of beasts, as of human beings. The time was, even within the limits of fifteen or twenty years, when it was customary, on driving a horse on the road, to feed him about every ten miles. This was enough to kill the poor animal; he had no time to digest his food and derive nourishment from it; and it is well that such a system has been abandoned; and it would be better still, if intelligent beings would adopt a similar rule of diet for themselves, and those under their care. Those who drive horses for pleasure-riding or in teaming, at this day, having proved the folly of the old system, feed regularly three times a day. Under this method, the animals eat, on the whole, less in quantity, are found in better order, and endure much more; and why? because they derive, by obedience to nature's law, more nourishment from the same food, and do not break down the digestive organs by oppressing them with too oft-repeated meals, And when individuals live as they list, and eat when they please, in disregard of right rules of diet, they commit a crime against nature. They pin against God, by treating with contempt his laws; they sin against their own bodies, by committing gradual suicide; and the penalty of those violated laws must be met -- there is no escape; the punishment will, in some way, sooner or later come. nature's own God will and must take this matter in hand, and sustain the validity of his own laws.
Now for the whys and wherefores of these directions. In the first place, food must be thoroughly masticated; this requires about HALF AN HOUR; especially at dinner, which is, generally and properly, the principal meal for the day. Inattention to and curtailment of time necessary for mastication, is a violation of physical law at the very outset of the digestive process; and one which, more or less, deranges all the other steps. In the second place, when food is lodged in the stomach, it requires ordinarily about FOUR HOURS for this organ to perform its work, before the entire meal is disposed of and carried into the duodenum, or first intestine. Here are, then, at least four hours and a half required for the process thus far; and probably five hours are more often needed, than a period short of four and a half. Then, after this, there remains the process of chylifaction to be finished.
Therefore, no two meals or luncheons should be allowed to come nearer to each other than a distance of at least FIVE HOURS. Because, as any one can see, there is a regular routine of steps, in the process of digestion, to be gone through with in this space of five hours. And if a second meal or lunch be taken short of that period, it produces confusion; the process with the first meal is interrupted; the organs are obliged to stop their course and begin a new process with the second meal: there will be probably a struggle between the two processes, and both be imperfectly performed. By this course, the organs are weakened, and the amount of nutrition from a given quantity of food is much less. To illustrate this method of proceeding and its effects, suppose an omnibus, running between Boston and Cambridge, should set out from Brattle-street with passengers, and after passing half way to Cambridge, the driver should recollect that there are a number more passengers whom he had forgotten; but instead of finishing his present route, and taking those left behind at the next regular trip, he wheels about, brings his load back, takes in the rest, and again proceeds. Precisely analogous to this, is the course which multitudes take in respect to their eating; one meal is half digested, and another is crowded upon it. The organs are kept continually at work, without systematic order, and without chance to rest and recruit their energies.
The good effects of regular and simple diet may be seen by visiting our prisons. There the inmates are generally in possession of good health, notwithstanding their confinement and close air. Some have gone there greatly afflicted with dyspepsia, but have obtained a complete cure, and become robust; and this at the time there must unavoidably have been a great and constant mental oppression. This is incontrovertible testimony in favor of plain and regular living.
Besides the positive injury done to the digestive organs themselves, by eating too often, and, by injury to those organs, a sympathetic injury to the whole system, there is a sort of negative injury done to the entire system by the interruption of the process of nutrition. After breakfast has been taken, let a lunch be eaten about eleven o'clock, and the process of chylifaction and nutrition is broken up, by the digestive energies being attracted too soon to the work of disposing of the eleven o'clock lunch; and so on in the same manner so long as meals and lunches succeed each other without giving at least five hours space for digestion. Hence, the system receives less nourishment from about twice the quantity of food per day, than it would receive under a regular, systematic diet, with a regular quantity.
It is argued by some that the inclination to eat is a proper guide to the time and frequency of eating. But this is no rule at all; if we eat ten times a day habitually, the stomach is obliged to undergo such a change in its action, that we shall think we are hungry as many times. There comes up a disordered action of the stomach, and a morbid appetite ensues. What sort of a guide is a man's inclination to eat who is just merging from the prostrating power of a typhus fever? And why is it that those who are always eating are always hungry; while those who live on three meals a day are not inclined to eat till the regular meal-time comes?
But why contend against facts established by the researches of learned physiologists? They have given us the time required for digestion; we know that this being correctly ascertained, we cannot interrupt that process without detriment. And who is willing to sacrifice justice to himself, and to the Author of his being, for the paltry gratification of a moment? Thousands do it; but it seems too uncharitable to suppose they would do it with their eyes open; though it is to be feared too many are willingly blind.
Whoever knows no law hut the fearful dictates of carnal appetites, is like a ship, driven by fierce winds coastward, without anchor. If we would do right -- if we would act upon principle -- we must obey every righteous law. That is a safe and prosperous government where obedience to law is sustained; that is a well regulated physical system whose physical law is obeyed. But how sadly this law is trampled under foot. How many there are who reverse one of the best rules of life: while all should EAT TO LIVE, they, impiously and wantonly, LIVE TO EAT. In this way, they destroy the very foundation of all true enjoyment from temporal sources, and prejudice the prospect for the future life. The old heathen adage, "Let us eat and drink, for to-morrow we die," is the sum and substance of their theology -- they know no God but their belly.