The Physiology of Digestion by Andrew Combe, M.B. (1837)
Part II. The Principles of Dietetics viewed in Relation to the Laws of Digestion
The Physiology of Digestion by Andrew Combe, M.D., Forth American Edition, was published By Marsch, Capen & Lyon in Boston in 1837. Andrew Combe was a physician in ordinary to their Majesties the King and Queen of the Belgians, and a Fellow of the Royal College of Physicians of Edinburgh. The third edition of this book was sold in 3000 copies. The text of this book of 310 pages will be found here, completely unchanged.
TIMES OF EATING.
The selection of food only one element in sound digestion. - Othe conditions essential. - Times of eating. - No stated hours for eating. - Five or six hours of interval between meals generally sufficient. - But must vary according to circumtances. - Habit has much influence. - Proper time for breakfast depends on constitution, health, and mode of life. - Interval required between breakfast and dinner - best time for dinner - circumstances in which lunch is proper - late dinners considered - their propiety dependant on mode of life. - Tea and coffee as a third meal - useful in certain circumtances. - Supper considered. - General rule as to meals. - Nature admits of variety, - illustrations - but requires the observance of principle in our rules.
Having, in the first part of the present work, traced the progress of the food through its successive stages of preparation for becoming a constituent element of the animal frame, and examined the structure and nature of the various organs engaged in digestion, I shall now endeavour to turn the exposition to account, by making it, as far as possible, subservient to a closer and more rational observance of the laws of digestion, and to a better adaptation of diet and regimen to different ages, sexes, and constitutions, than that which is generally prevalent. I am deeply sensible of the imperfections which will abound in this part of the work; but, at the same time, I am so strongly impressed with the urgent importance of the subject, and with the success which will infallibly attend its further investigation on sound physiological principles, that I consider the likelihood of personal failure to be of very secondary importance, when compared with the benefits which will accrue to society from the exertions of others whose labours may be more profitably directed by an acquaintance with the guiding principles unfolded in these pages.
According to the popular notions of dietetics, the selection of the proper kind of food seems to constitute the only condition required for the enjoyment of healthy digestion. Hence medical men are constantly questioned whether this or that article of diet is good or bad for the stomach, while curiosity rarely, if ever, extends so far as to inquire whether nature has annexed any other conditions which also it may be expedient to know and to observe. In reality, however, the choice of aliment is but one out of many circumstances which require to be attended to; and it often happens that the same food which is digested with ease when the collateral conditions are fulfilled, will remain for hours on the stomach unaltered when they are neglected. Some of these conditions, therefore, I shall now endeavour to point out. And, first, of
TIMES OF EATING. - If we look to the exposition of the objects of eating already given in treating of appetite, it will be obvious that nature intended us to regulate our meals by the demands of the system, and not to eat at stated hours as a matter of course, whether nourishment were required or not. If we are engaged in exercises which induce a rapid expenditure of material, or if growth is going on so rapidly as to require unusually ample supplies, food ought to be taken both more frequently and in larger quantity than when we are differently circumstanced; or, in other words, food ought to bear a relation to the mode of life and circumstances of the individual, and not be determined by a reference to time alone.
As society is constituted, however, there is so much uniformity of occupation in the different classes of which it is composed, and the animal economy is other is otherwise so much adapted to the performance of periodical operations, that stated times may with advantage be fixed for each class, and thus the benefits of that social and exhilaring intercourse which we all see to be so conducive to healthy digestion may be generally obtained. Individuals may suffer a little from this arrangement, but the wast majority will undoubtedly be benefited.
Where the mode of life is regular and nearly the same throughout a whole class, the same waste will go on, and the same demand for a supply of nourishment occur, throughout all the individuals composing it, subject only to such variations as are induced by original differences of age and constitution. Consequently, as regards such a class, regularity in the recurrence of their meals is not less natural than advantageous; because not only are all the individuals subjected to nearly the same exertions, but every day is so like another, that the want will always be felt at the same hour; and it is only when we attempt to combine the same order of diet with different and even incompatible modes of life, that nature refuses to sanction the arrangement.
So strong, indeed, is the tendency to periodicity in the system, that appetite returns for a time at the accustomed hour, even after the mode of life, and consequently the wants of the system, have undergone a change; and if not gratified it again subsides. Ultimately, however, it calls with too strong a voice to allow of its being thus disregarded.
Nature has accorded to man considerable latitude in fixing the interval within which the demands of appetite must be gratified, and in this provision has obviously had in view the infinite variety of circumstances in which he may be placed in the discharge of his numerous duties. As a general rule, five or six hours should elapse between one meal and another - longer if the mode of life be indolent, shorter if very active. Digestion occupies from three to four or five hours, and the stomach requires an interval of rest after the process is finished, to enable it to recover its tone, before it can again enter upon the vigorous performance of its function. Appetite, accordingly, does not begin to show itself till some time after the stomach has been empty, and if food be taken before it has recovered its tone, the secretion of gastric juice and the contracting of tis muscular fibres are alike imperfect, and digestion consequently becomes impaired.
The interval between each meal ought to be longer or shorter in proportion to the quantity eaten, and to the more or less active habits of the individual; and it would be absurd to fix the same standard for all. A strong labouring man, whose system is subjected to great waste from being engaged all day in hard work, will require not only more frequent, but more copious meals than an indolent and sedentary man; and those who eat very little will require to eat at shorter intervals than those whose meals are heavy. An invalid on restricted diet may thus require to eat every four hours, where formerly, with a more copious diet, once in six hours was sufficient. Some indeed are so constituted as to require only one or two abundant meals in twentyfour hours.
Early training exercises great power over the stomach as well as over the mind. In savage life, where the supplies of food are precarious, a single meal may be copious enough to serve for two or three days together. The monks of La Trappe make it a part of their religion to eat only once a day, and nothing but vegetable food - unless when sick, in which case milk is allowed; but it is long before they become reconciled to the restriction. I once travelled for three days in a French diligence with one of the order, then on his way from Italy to the Monastery of La Trappe, near Nantes, and observed that he scrupulously adhered to his single meal. He had a dispensation, however, authorizing him to eat animal food and use wine during his journey; and I was surprised at the extent to which he availed himself of the permission, and to see him devour at one time a store sufficient to last for a weak instead of a day. But, as in the case of the boa constrictor in similar circumstances, a deep lethargy immediately succeeded, and it was not till four or five hours afterward that his almost apoplectic features became again animated and expressive; long before hist time came round, however, his renewed appetite betrayed itself by expressive glances towards the comforts of the breakfast-table.
Nature, then, has fixed no particular hours for eating, but has left us to adapt our regimen to our respective ages, constitutions, and modes of life. Where the mode of life is uniform, fixed hours may be adopted; where it is irregular, we ought to be guided by the real wants of the system as indicated by appetite.
According to this principle, meals ought to be early or late in proportion to the habits of the individual. If, adhering to the order of nature, we work by day and sleep by night, then early breakfast, early dinner, and an early evening meal, will undoubtedly be the most conducive to sound digestion and the enjoyment of health. But if, against the laws of nature, we rise from bed late in the forenoon, reserve our activity till late in the afternoon, and do not go to sleep till two or three hours before daybreak, then assuredly the late breakfasts and dinners of the fashionable society of the present day are the best for our comfort that can be devised; and the chief error lies in the practice of those, who, while they in other respects live in conformity with nature, adopt the hours which are suitable for those only who turn night into day and day into night.
The proper time for taking breakfast depends a good deal on the individual constitution and mode of life. Those who eat supper ought not to breakfast till one or two hours at least after rising; but persons who dine late and eat nothing afterward require breakfast sooner. Individuals of a delicate frame are often unable for eihter bodily or mental exertion in the morning, and are invariably injured by any attempt at exercise or serious thinking before breakfast. Experience is the only sure guide in such cases, but, as a general rule, breakfast about half an hour or an hour after rising will be found most beneficial; and those who rise very early will do well to follow the French custom of taking a small cup of coffee or tea, and bread, on getting up, and reserve their appetite for a more substantial breakfast three hours later. This is an invaluable rule for students, who often seriously impair their digestive functions by studying for hours in the morning, regardless of the craving of the system for nourishment and support.
If exposure of any kind is to be incurred in the morning, whether to the weather or to the causes of disease, it becomes a matter of much importance that breakfast should be taken previously. It is well known that the system is more susceptible of infection, and of the influence of cold, miasma, and other morbid causes, in the morning before eating than at any other time; and hence it has become a point of duty with all naval and military commanders, especially in bad climates, always to give their men breakfast before exposing them to morning dews or other noxious influences. Sir George Ballingall even mentions a regiment quartered in Newcastle, in which typhus fever was very prevalent, and in which, of all the means used to check its progress, nothing proved nearly so successful as an early breakfast of warm coffee. In aguish countries, also, experience has shown that the proportion of sick among those who are exposed to the open air before getting any thing to eat, it infinitely greater than among those who have been fortified by a comfortable breakfast. Where there is any delicacy of constitution, the risk is of course increased.
The cause of this susceptibility in the morning is not difficult to be discovered. Not only have the stomach, duodenum, and upper intestine been entirely empty for several hours, but the absorbents and other parts engaged in the function of alimentation have likewise been in a state of repose. A considerable exhalation from the skin and lungs has at the same time been going on; and this, taken along with the deposition, which there is reason to believe takes place more actively during sleep, of new particles to the existing organization, necessarily reduces the quantity and quality of the circulating fluids, and gives rise to a certain degree of debility, which is favourable to the action of any morbid cause, and which can be removed only by a supply of that nourishment of which the system stands so much in need, and for which the digestive organs are so vigorously prepared. The loss of fluids during the night by insensible perspiration is said by Sanctorius to be twice as much as when awake. This, and the loss by pulmonary exhalation, cause a corresponding demand for fluids in the morning, and hence the reason why our first daily meal is almost universally of more fluid and less substantial description than any of the subsequent ones; while our active exertion and loss of solids during the day create a proportionate demand for a more substantial repast in the afternoon.
The function of absorption is thus at its highest pitch of activity in the morning; and if the body be exposed to miasma of other impurities, they will be much more easily and speedily absorbed by the skin, the pulmonary membrane, and the stomach before eating, thatn after the absorbents have been supplied with their legitimate food. This is the true theory of the greater susceptibility of infection and other poisonous influences when the stomach is empty.
So rapid is absorption from the stomach in the morning, that I have repeatedly seen nine tumblers of a saline mineral water taken at eight o´clock, and a very hearty breakfast finished within half an hour after the water was drunk! When in bad health three years ago, I observed almost equal expedition in my own person. I took half a pint of ass´s milk at seven o´clock, and in consequence of coughing violently, was frequently seized with vomiting and retching within twenty minutes after taking it; but only twice or thrice was any portion of the milk perceptible, although the stomach was entirely emptied. This was even more remarkable than the other case, inasmuch as milk undergoes digestion, which water does not. In allusion to this rapidity of absorption, Sir Francis Head, in speaking of the quantity of the chalybeate waters swallowed of a morning at the Brunnens of Nassau, humorously remarks, that "one would think that this deluge of cold water would leave little room for tea and sugar; but, miraculous as it may sound, by the time I got to my ´Hof´, there was as much stowage in the vessel as when she sailed; besides this, the steel created an appetite which it was very difficult to govern." (Bubbles from the Brunnens of Nassaeu, p. 46.)
In setting out early to travel, a light breakfast before starting is a great protection against colds and subsequent fatigue or exhaustion. I am quite aware that robust and healthy men can and do take much active exercise before breakfast, with apparent impunity, if not benefit, and I have often done so myself; but experience ultimately taught me that I became sooner exhausted on continuing the exertion through the day, than when I began by eating a little. During the first winter of my studies in Paris, I regularly attended the surgical visits at the Hotel Dieu, which began at six o´clock in the morning, and lasted till nine, or frequently half past nine. Not being then aware of the principle under discussion, I ate nothing till my return home; but I felt more weariness before the day was done than the mere exertion ought to have produced. At last, on noticing for a time the regularity with which many of the workpeople passing along paid their respects at a smal shop, the only one then open, where fancy rolls were sold, along with wine and brandy, I thought of following their example, and trying how far a roll would add to my comfort, and impart additional vigour to the system. I soon found great reason to be pleased with the expedient, and discovered that I was not only less exhausted during the day, but more able to follow the lecture which concluded the visit, and in possession of a keener appetite for breakfast at my return; and ever since I have acted on the principle now inculcated, and with marked benefit. I was then astonished at the regularity with which the Parisian workmen seemed to take their morning dose, or petit verre of brandy, on their way to their labours, apparently for the very purpose of getting that wholesome energy which they ought to have sought in food alone.
During the prevalence of cholera, both here and on the Continent, it was often remarked that a large proportion of the attacks occured early in the morning, in persons who had gone to bed apparently well. Chronic invalids and persons of a delicate habit of body are also familiar with the fact of the animal heat and general vigour diminishing towards morning. When reduced in strength by pulmonary complaints, I often passed the night in comparative comfort, sure to awake about five or six o´clock with a feeling of chill and absence of animal heat, which I could not dissipate till after receiving sustenance.
From these facts, the general inference is clearly warranted, that delicate persons ought to have some kind of food soon after rising, and that even those who are healthy will act wisely in not exposing themselves unnecessarily to fatigue, infection, or other morbid causes, wihtout having previously supplied the wants of the system, either partially by a cup of coffee or tea, or entirely by regular breakfast. Where fever, for example, is in a family, the danger of infection will be much greater to a person going directly from his own bed to the bedside of the patient, than to one who first takes the precaution of drinking were it only a cup of coffee. I have elsewhere noticed the safety which Captain Murray obtained for his crew in the West Indies, partly by attention to this rule; and have likewise referred to the experience of Sir George Ballingall even in our own climate. (See the Principles of Physiology, &c., chap. iii.)
In boarding-schools for the young and growing, who require plenty of sustenance, and are often obliged to rise early, an early breakfast is an almost indispensable condition of health. On the Continent, in similar establishments, seven o´clock is the common hour for breakfast, especially in summer.
In recommending what I conceive ought to be the general rule, let me not be understood as wishing to extend it so far as to advise those whose constitution admid of two or three hours´ activity before breakfast, to abandon what experience proves to be beneficial to them. My only wish is to help those who are in doubt as to choosing the plan which is most likely to be of advantage, and to relieve those who are already suffering from ignorance.
The morning meal being comparatively a light one, and the stomach being then in high vigour, digestion goes on briskly, so that appetite revives within a shorter time than after the more substantial dinner. Accordingly, in all nations and classes of society not perverted from the course of nature a longer interval than five hours rarely elapses between breakfast and dinner. Our forefathers dined at noon, as our sailors continue to do at the present day; and over no small portion of the Continent of Europe, the same primitive hour is still adhered to; and among the labouring population of Great Britain, on or two o´clock is the common dinner-hour, nine being that of breakfast. The universality of a mid-day meal among those who rise early, is itself a strong presumption in favour of its propriety, and of its being in harmony with the laws of the animal economy.
To prevent business from interfering unduly with digestion, it was formerly the custom in Edinburgh to shut up shops and counting-houses for two hours in the middle of the day; and in Switzerland, the same practice is or lately was prevalent. The members of the family being then assembled, relaxation and enjoyment take the place of the cares of the world; and the result is highly satisfactory. The appetite is keen enough to induce them to eat with zest all that nature requires, while it wants the resistless force which is given by a fast of eight or nine hours. There is consequently slower mastication, less cramming, and a much earlier return of the aptitude for business; while at the same time the mental and bodily faculties are refreshed by the interruption of their accustomed labour, and the affections cherished by healthful domestic intercourse taking place before too much weariness is induced to permit of its being enjoyed. In England, such weariness is a very common occurrence. The parent and husband, exhausted by the eager pursuit of wealth during the livelong day, returns home in the evening jaded and harassed, and little able to take pleasure or interest in the enjoyments of his wife and family. Hence, indeed, too often arise indifference and unhappiness between those whom nature has formed as if on purpose to suit each other.
In enterprising comercial communities - in London and Liverpool for example - it is a common practice to hasten away to the counting-room immediately after an early breakfast; to remain there in active employment from nine or ten o´clock in the morning till six o´clock in the evening, and then to hurry home to a late dinner at six or seven o´clock; by which time the vital functions have become so far exhausted, as to create a strong desire for indulgence in something stimulating both in food and drink. If this desire be gratified, immediate relief is obtained, and a feeling of comfort pervades the frame; but nothing can be more erroneous than to regard this as a proof of the indulgence being beneficial. The organization soon gets accustomed to the stimulus; its susceptibility bedomes impaired by the frequency with which the latter is administered; and in a short time indigestion is the inevitable consequence.
The evils attendant on this course of life are not unfrequently aggravated by the preposterous means resorted to for their prevention. Having some vague notion that exercise improves digestion, and not being at all aware that there is an improper as well as a proper time for taking it, many persons, after being exhausted by seven or eight hours´ confinement to the counting-house, proceed to take a walk for four or five miles before going home to dinner, and thus utterly throw away the little strength that was left to them, and are filled with disappointment on finding their appetite and digestion worse than before (Respecting the proper regulation of exercise, see The Principles of Physiology, chap. iv.). Dr. Paris mentions the case of a clerk in a public office, who brought upon himself all the horrors of dyspepsy and melancholy by following this plan. He breakfasted at nine, went to his office at ten, continued there till five, walked till seven, and then dined. He was cured in six weeks, by adopting a more rational regimen and dining at three o´clock.
Many females and delicate persons injure their powers of digestion by delaying their exercise till the system is too much exhausted to profit by it. In boarding-schools the same error is often committed from the desire which is felt to have all the lessons over before allowing any play.
As a general rule, then, not more than five hours ought to intervene between breakfast and dinner. If the mode of life be such as involves great activity in the open air, or the period of life be one of rapid growth or filling up (as during youth or convalescence from illness), the interval may with propriety be shortened; whereas, if the mode of life be sedentary, and unattended with much activity of nutrition, the interval may be considerably protracted without inconvenience. Much, also, ought to depend on the natural rapidity or slowness of digestion. In some constitutions, chylification goes on so slowly that the individual can pass with ease eight to ten hours without food; whereas, in others, it is so rapid that a fresh supply becomes necessary in half the time. The proper rule in every case is, to take dinner at such an interval after breakfast as the return of healthy appetite indicates, whether that interval be longer or shorter than the average specified.
That, according to this rule, the general time for dinner ought to be somewhere about five hours after an ordinary breakfast, is evident from the almost universal return of appetite at the end of such an interval, and from the fact that many, through sheer inability to resist longer the wholesome cravings of nature, are in the regular practice of eating dinner at that time, but to save appearances give ti the name of luncheon; by which means they hold themselves entitled to the enjoyment of a second and more substantial dinner later in the day.
Invalids, dyspeptics, and all who, possessing vigorous digestion, wish to retain it, will do well to follow teh intentions of nature, and observe the intervals which she has appointed. Those who disregard them, and still digest without difficulty, have reason to be grateful to Providence; but they may rest assured that they will longer enjoy their privilege, and better evince their gratitude, by submitting their conduct to the ordinary laws of the animal economy, than by presuming too much on their supposed exemption from the salutary restraints of reason and experience.
Supposing nine o´clock to be the hour of breakfast, the natural dinner-hour would thus be two o´clock; and such, accordingly, is that sanctioned by the most extended experience, and which ought to be adhered to by all whose occupations will admit of its observance, and who wish to enjoy the highest health of which they are susceptible.
Artificially arranged, however, as society now is, whole classes of the community find it impossible to dine till much later in the day. The question then comes to be - As we cannot follow the system laid down by nature, what is the next best to be done? Ought we to eat nothing till we can find time to dine at five, six or seven o´clock; or ought we rather to take a light meal at the natural time, about one or two o´clock, and reserve our appetite chiefly for the substantial meal which we have leisure to digest?
The principle in virtue of which digestion is interrupted by bodily or mental labour occuring after a full meal, having been already sufficiently explained, it needs scarcely be added, that the second is the better plan; and moreover, that by leaving the stomach too empty, we risk impairing its functions and weakening the system.
When dinner cannot be taken earlier than seven or eight hours after breakfast, most people will find it advantageous to partake of some slight refreshment in the meantime - enough to blunt the keeness of appetite, but not entirely to destroy it. When the individual is exposed to much bodily exertion in the open air, or is at the period of rapid growth, a portion of animal food, or an ordinary luncheon, taken in moderation, may be allowable, and even requisite; but where the habits are sedentary and the constitution formed, a bit of bread or biscuit and a glass of water will be far more serviceable. Many people, from want of any better occupation, make a pastime of filling their stomachs every forenoon at the pastry-cook´s, with as little regard to its powers and necessities as if digestion were meant merely as an appendage to taste; and think themselves entitled to complain of their defective appetites, and the great discomfort which attends the subsequent ingestion of a heavy dinner. To relieve the weakness, arising not from exhaustion, but from the oppression of satiety, they resort to wine, as if by adding fuel to the fire they could hope to extinguish the flame!
Even in fashionable life the superiority of nature´s arrangements over those of man is so far acknowledged, that it is an almost universal rule for children to dine in the middle of the day; and there cannot be a doubt that the practice is attended with manifold advantages to the young, although, as regards their moral training, these would be greatly increased were they to associate at meals with their parents, instead of being left entirely to the company and management of servants.
Supposing it to be made an imperative condition of our social existence that we shall rise after midday, and not go to bed till late hour in the morning, the present fashion of dining at seven or eight o´clock becomes much more rational than is commonly imagined by those who declaim against it without regard to the concomitant circumstances. It is, no doubt, most absurd and hurtful for a man who rises at seven or eight o´clock, breakfasts at nine, and goes to bed at eleven, to delay dining till seven in the evening; but it by no means follows that seven is a bad dinner-hour for a person who rises at twelve or one o´clock, breakfasts at two, and goes to bed at three in the morning. The interval between the breakfast at one and dinner at seven o´clock, is the same as between breakfast at nine and dinner at three, namely, six hours - which is little more than enough. The error lies, not in the hours chosen for meals, but in the utter perversion of the whole system of living, by which night is converted into day, and the business of life is postponed five or six hours beyond the time appointed by the Creator for its performance. So far from the late dinner being hurtful in such circumstances, it is only the stimulus and support which it affords that enables the victims to withstand the fatigue even for a single week.
No one has a stronger sense of the injury done to society by the wide departure from the laws of nature by which its present arrangements are characterized, and no one is more willing to contribute all that is within his power to reform them, than the writer of these pages; but let the whole system be amended, and do not limit the reform simply to altering the hour of dinner, while the conditions which have led to the existing arrangement are left unchanged.
In the country, even among the higher classes, a greater approximation to the order of nature is observable than in towns. The inducements to sleep away the day and to be awake during the night are diminished; bodily exercise and exposure to the open air are more indulged in; the appetite becomes keener, and digestion more vigorous; and, as a necessary result, meals are taken an hour or two earlier. But, throughout all these changes, the general feature of having some kind of refreshment, either luncheon or dinner, within four, five, or six hours after breakfast, may be pretty accurately traced.
If business admits it, and the person can then command two hours of relaxation, the best plan, unquestionably, is to dine about five or six hours after breakfast. But if this be impossible, and active exertion of mind or body must be continued for several hours longer, it will be far better to eat some light refreshment it the forenoon, and to postpone dinner not only till business is over, but till half an hour or an hour´s repose has allowed its attendant excitement or fatigue to subside. By this means the stomach will enter upon its duties with vigour, and the dinner be digested with greater comfort and despatch, than if we sit down to the table the moment our work is finished. In this way, the tedious quarter of an hour preceding the announcement of "dinner" if far from being lost to the subsequent digestion.
Very few people, indeed, can eat a good dinner and return immediately to bodily or intellectual labour with continued impunity. On this account , actors, for example, whose vocation requires extertion of both mind and body, almost all either dine very early, or take their chief meal at night on their return home, the latter being the more common practice. Students, litterary men, and persons intently engaged in business, are very apt to damage themselves by neglecting relaxation at and after meals.
The time for dinner ought, then, to vary according to the constitution, occupations, and mode of life of the individual; and the nearer the whole of these can be made to approximate to the intentions of nature, the more vigorous will be the powers of digestion, and the more complete the nutrition of the body; and, consequently, the more easily will the stomach recover the tone which it may have lost from previous mismanagement. In attempting to cure indigestion, notwithstanding the most scrupulous adherence to the rules given for the proper selection of food, if we set at defiance all the other conditions of healthy digestion, our adherence will be of little avail. Whereas, if we fulfil the laws of our constitution, by rising from bed in the morning, obtaining a healthy appetite and lively circulation by the regular exercise of the various functions of mind and body in a free and pure atmosphere, eating moderately, and enjoying social relaxation after our meals - digestion will be so far strengthened, that no very rigid observance of any particular kind of diet will be necessary; it being always understood, however, that we shall not exceed in quantity what the wants of the system require.
It would be a waste of time to discuss gravely whether tea and coffee ought to be allowed in the evening. Custom has already decided the point, and experience has shown that, taken in moderation, they rather promote than impede digestion. When the dinner is early - say at one, two, or three o´clock - a light meal of tea and bread in the evening is very suitable, as it saves the necessity of eating a heavier supper. If the individual be accustomed to much active exertion in the afternoon, so as to cause considerable waste in the system, and especially if he be young, a small addition of animal food may be made with great propriety to the evening meal. But, on the other hand, when the dinner is late, or little exertion is incurred after it, tea or coffee ought to be used more as a diluent than as a meal.
The French drink a single cup of strong coffee without cream immediately after dinner, and find digestion go on all the better for it. It acts as a strong stimulant, and certainly increases the feeling of comfort for the time. Like all other stimulants, however, its use is attended with the disadvantage of exhausting the sensibility of the part on which it acts, and inducing weakness. This inconvenience is not felt to the same extent, indeed, after coffee as after spirits, but still it exists; and it is infinitely better that the stomach should be brought up to do its own work ungrudgingly, than taught to depend upon assistance from without; and, therefore, such assistance ought to be reserved for the relief of occasional exhaustion, instead of being resorted to as a regular indulgence. The French partake of a much greater variety of dishes at one meal than we are accustomed to do, and may thus require the aid of coffee to keep the stomach from actual rebellion. But the way to obviate this necessity is obviously to eat a more simple and more moderate meal.
A great deal has been said and written about the properties of tea and coffee as articles of diet. At present, however, we have to do with them only as elements of a third meal, and must reserve the discussion of the other branch of the subject to a future opportunity.
In determining whether a third meal ought to be taken, either as tea or as supper, the general principle already laid down will be very useful. If dinner be sufficiently early to admit of digestion being completed, and the stomach afterward recruited by repose, and if the mode of life be active, so as to occasion a natural return of appetite before the day is done, the propriety of a third meal cannot be questioned. But if dinner be late, and there be too short an interval between it and bedtime to admit of digestion being finished and the appetite renewed, then every additional mouthful swallowed is sure to do mischief. The farmer who dines at two o´clock, for example, and, after walking about his fields for three or four hours in the afternoon, comes home in the evening with a genuine and undeniable appetite, has a legitimate right to an additional supply of wholesome food before betaking himself to his couch; because a sufficient interval has elapsed to allow the stomach to recover itself from the labour of digesting his dinner, and the continued waste of the system requires to be replaced. In like manner, the man of fashion, who dines at seven o´clock, and frequents assemblies till three or four in the morning, is well entitled to some kind of supper about one or two o´clock, and could scarcely get through his laborious duties without farther sustenance from either food or wine, or both. Even in his case, six hours may thus intervene between dinner and supper; and we know that, on an average, digestion is finished in four or five hours. The chief difference between him and the farmer is, that the farmer reaps health and sound digestion from adhering in his hours to the institutions of the Creator, and that the man of fashion impairs his constitution and enfeebles his digestion - less by the improper intervals at which he eats, than by his wide departure from the order of nature in the hours which he observes.
If, in adopting the precepts of ultra-temperance, we dine early, live actively, an go to bed with the stomach entirely empty, we may sleep, but our dreams will scarcely be more pleasant, or our sleep more tranquil, than if the stomach were overloaded. A gnawing sense of vacuity is felt in such circumstances, which is apt to induce restlessness, and nervous impatience and irritability. I have repeatedly seen these unpleasant symptoms dispelled, and sound sleep obtained, by no other prescription than a cupful of arrow-root an hour or two before bedtime.
Except in early life, and in the case of those who lead a very laborious existence, and observe very early hours, supper as a fourth meal is altogether superfluous, at least where any thing is eaten at tea. In youth, waste, growth, and nutrition are so active, that a moderate supper is often indispensable, especially when the muscular system is freely exercised in the open air. But it ought to be of a light nature, and taken at least an hour or two before going to bed. If dinner be taken early, and tea be used in the afternoon, not as a meal, but merely as a diluent, a light supper will be very proper.
In short, the grand rule in fixing the number and periods of our meals is, to proportion them to the real wants of the system, as modified by age, sex, health, and manner of life, and as indicated by the true returns of appetite; and, as an approximative guide, to bear in mind that, under ordinary circumstances of activity and health, three, four, or five hours are required for the digestion of a full meal, and one or two hours more of repose before the stomach can again become fit for the resumption of its labours. If the meal be temperate and the mode of life natural, digestion will be completed in from three to four hours, and one hour of rest will serve to restore its tone; but if the quantity of food be great, or the general habits be those of indolence, digestion may be protracted to five or six hours, and two or more be required for subsequent repose. It is therefore utterly absurd and inconsistent with the laws of nature to pretend, as many writers have done, to lay down rules which shall apply to every individual and to every variety of circumstances. As already mentioned, rules applicable to classes may be prescribed, because there is a considerable similarity in the circumstances of all the individuals comprehended in it; but even there numerous exceptions must occur, which can be judged only by the standard of the individual constitution.
The Creator indeed has obviously never intended that we should be bound down to the rigid observance of a very strict order in diet; but, to fit us for the ever-varying circumstances in which we are placed, has wisely and benevolently allowed us considerable latitude, and made appetite to vary in the extent and earnestness of its demands in proportion to the waste to which we are subjected for the time. It is astonishing how rapidly a healthy frame accomodates itself even to great changes, when temperance is duly observed, and a proper regard is paid to the intimations of appetite.
In suiting my own mode of life to the circumstances under which I have at various times been placed, I have repeatedly, even as an invalid, made sudden changes in the hours of eating, with no further injury than temporary discomfort; but then I always adhered to the general principles above insisted on. It was by some of these experiments that my attention was first drawn to the great influence of the accessary conditions in retarding or promoting digestion. At one time, on altering my place of residence from Aix to Marseilles, I changed at once from breakfasting at eight o´clock, dining at two, and taking tea in the evening, to breakfasting at eleven, and dining at six. For the first few days I felt uncomfortable in waiting so long in the morning; but by following the plan of taking a small cup of coffee and a crust of bread soon after rising, and attempting no active bodily exertion till after breakfast, every feeling of inconvenience ceased, and the system adapted itself to the change as completely as if it had never been accustomed to any thing else. Three months afterward I embarked on the Mediterranean, and again passed at once to breakfasting between seven and eight o´clock, dining about noon, and taking tea in the evening, which I continued to do for some time after arriving in Italy. On my way home the hours of eating were never two days the same, and yet I did not suffer. If breakfast was early, I ate it with relish. If it was late, I had recourse to a biscuit, or some dried fruit, early in the morning, to sustain the system in the meantime, and was ready for it when it came. In the same way, if dinner was today at one o´clock, I took it when it was offered, and had recourse to some refreshment in the evening: if to-morrow it was postponed till eight o´clock, which sometimes happened, the refreshement came in the forenoon, and a moderate meal was taken in the evening.
In these changes, however, it will be remarked, that the laws of digestion were in reality much less infringed upon as to time than one might imagine from merely hearing that I dined one day at noon and the next day at eight o´clock in the evening. At whatever hour the meal was taken, the real wants of the system were supplied when they manifested themselves in the form of appetite, and the requisite intervals were observed. If a substantial breakfast was taken at eight o´clock, then a corresponding interval elapsed before another meal followed at one or two. If, again, the morning allowance was trifling, then the real breakfast followed at an interval correspondingly short, namely, at eleven o´clock. So also with dinner. And if dinner was at one o´clock, tea followed at the distance of six or seven hours; whereas, if it came at six or seven o´clock, a refreshment preceded and nothing followed it, and the result was comfort and sound digestion. If, however, we yield unguardedly to the impulse of appetite in travelling, and eat and drink plentifully instead of temperately, no arrangement of hours that we can make will render our situation either pleasant or healthful.
While, therefore, it seems to be obvious beyond a doubt, that those who live according to the laws of nature and begin their activity with the morning, should breakfast betimes, dine early in the day, and take a lighter meal in the evening, and that those who do so will reap a reward in health and vigour of mind and body unttainable to the same extent by those who live differently, and convert night into day, - it would be not less hurtful than absurd to prescribe the same hours for meals to all, whatever their hours of activity, ant whatever their modes of life; and I cannot help thinking, that it is the preposterous attempt to generalize too much, which, losing sight of true principle and the modifications which it requires in individual cases, has brought dietetic precepts into disrepute, and led to the belief that the rules laid down are merely arbitrary assumptions, resting on no solid foundations in the human constitution, or in the designs of our Creator.
As experience is the best guide to knowledge, I may be allowed to add, that, when travelling on the continent in health and strength, I suffered more from feverish fatigue and stomachic discomfort, induced by ignorant infringement of the laws of digestion, than I ever afterward did, even from more continued exertion when traveling as an invalid under a better regulated system of diet. I did not, in either case, make any exception to the meals which awaited our arrival at the inns, or to the hours at which they were served. The chief difference was, that, when well, I ate till my appetite was fully satisfied, under the notion that, in travelling, a full diet is necessary to enable one to withstand the fatigue; and that, as an invalid, on the other hand, I ate more sparingly, and, if the regular meal was much later than usual, had recourse to biscuit, fruit, or a slice of cold meat, as an intermediate refreshment, to prevent the stomach becoming exhausted from too long a fast. Following the dictates of experience, I have long adhered to the latter plan, and am convinced that few who have tried both will long prefer the former.