Fasting has many scientifically proven benefits for your body and overall health:
Intermittent fasting improved blood pressure and resting heart rates as well as other heart-related measurements. Physical performance. Young men who fasted for 16 hours showed fat loss while maintaining muscle mass. Mice who were fed on alternate days showed better endurance in running. — Johns Hopkins Medicine
While Finxter is not a health blog and I am not a medical advisor, allow me to share this age-old wisdom from the book “The Fasting Cure” by Upton Sinclair.
Intermittent fasting has helped me and many other highly productive individuals create more value, stay more healthy, and maximize their productivity — in coding, business, or any other professional field.
💰 Fasting can make you more money—so keep reading!
This short book summary is based on the original book that can be downloaded for free here. I’ll give many direct quotes from the book but only the ones that I think are useful for you so you don’t have to read the whole book by yourself. All highlights are my own.
The Fasting Cure appeared in Cosmopolitan Magazine in the year 1910—you see: few things are as well-researched and well-understood as the benefits of fasting. More than 100 years later and scientists still agree on the benefits of fasting!
Like nobody would argue against the benefits of sleep, nobody can argue with the benefits of fasting.
Let that sink in. 🪨
The book starts with a strong opening paragraph about Perfect Health:
Have you any conception of what the phrase means? Can you form any image of what would be your feeling if every organ in your body were functioning perfectly? Perhaps you can go back to some day in your youth, when you got up early in the morning and went for a walk, and the spirit of the sunrise got into your blood, and you walked faster, and took deep breaths, and laughed aloud for the sheer happiness of being alive in such a world of beauty. And now you are grown older—and what would you give for the secret of that glorious feeling? What would you say if you were told that you could bring it back and keep it, not only for mornings, but for afternoons and evenings, and not as something accidental and mysterious, but as something which you yourself have created, and of which you are completely master? (source)
Everybody wants to be healthy, full of energy, and free from pain. Being healthy means not only a much better quality of life, but health is also the source of all human productivity.
The more you lose health, the less you get done. So spend some time on your health daily!
It is simply that for ten years I have been studying the ill health of myself and of the men and women around me. And I have found the cause and the remedy. I have not only found good health, but perfect health; I have found a new state of being, a new potentiality of life; a sense of lightness and cleanness and joyfulness, such as I did not know could exist in the human body. (source)
Next, the book goes into some personal stories of the health struggles of the author, while interesting, we’ll skip over them quickly—time is scarce.
Here’s the kicker story that made the author act on the fasting cure:
So matters stood when I chanced to meet a lady, whose radiant complexion and extraordinary health were a matter of remark to everyone. I was surprised to hear that for ten or fifteen years, and until quite recently, she had been a bed-ridden invalid. She had lived the lonely existence of a pioneer’s wife, and had raised a family under conditions of shocking ill-health. She had suffered from sciatica and acute rheumatism; from a chronic intestinal trouble which the doctors called “intermittent peritonitis”; from intense nervous weakness, melancholy, and chronic catarrh, causing deafness. […] And this woman, when she took the ride, had not eaten a particle of food for four days previously! […] That was the clue to her escape: she had cured herself by a fast. She had abstained from food for eight days, and all her troubles had fallen from her. Afterwards she had taken her eldest son, a senior at Stanford, and another friend of his, and fasted twelve days with them, and cured them of nervous dyspepsia. And then she had taken a woman friend, the wife of a Stanford professor, and cured her of rheumatism by a week’s fast. I had heard of the fasting cure, but this was the first time I had met with it. […] After another spell of hard work I found myself unable to digest corn-meal mush and milk; and so I was ready for a fast. (source)
Next, the author describes how he implemented his first fasting streak and how it helped him resolve his limitations of certain types of foods:
I had not taken what is called a “complete” fast—that is, I had not waited until hunger returned. Therefore I began again. I intended only a short fast, but I found that hunger ceased again, and, much to my surprise, I had none of the former weakness. I took a cold bath and a vigorous rub twice a day; I walked four miles every morning, and did light gymnasium work, and with nothing save a slight tendency to chilliness to let me know that I was fasting. I lost nine pounds in eight days, and then went for a week longer on oranges and figs, and made up most of the weight on these.
I shall always remember with amusement the anxious caution with which I now began to taste the various foods which before had caused me trouble. Bananas, acid fruits, peanut butter—I tried them one by one, and then in combination, and so realized with a thrill of exultation that every trace of my old trouble was gone. (source)
Let’s dive into some of the benefits of fasting and learn a couple of more insights into its working. Don’t forget that this was already figured out more than one hundred years ago!
The fast is to me the key to eternal youth, the secret of perfect and permanent health. I would not take anything in all the world for my knowledge of it. It is Nature’s safety-valve, an automatic protection against disease. I do not venture to assert that I am proof against virulent diseases, such as smallpox or typhoid. I know one ardent physical culturist, a physician, who takes typhoid germs at intervals in order to prove his immunity, but I should not care to go that far; it is enough for me to know that I am proof against all the common infections which plague us, and against all the “chronic” troubles. And I shall continue so just as long as I stand by my present resolve, which is to fast at the slightest hint of any symptom of ill-being—a cold or a headache, a feeling of depression, or a coated tongue, or a scratch on the finger which does not heal quickly.
Those who have made a study of the fast explain its miracles in the following way: Superfluous nutriment is taken into the system and ferments, and the body is filled with a greater quantity of poisonous matter than the organs of elimination can handle. The result is the clogging of these organs and of the blood-vessels—such is the meaning of headaches and rheumatism, arteriosclerosis, paralysis, apoplexy, Bright’s disease, cirrhosis, etc. And by impairing the blood and lowering the vitality, this same condition prepares the system for infection—for “colds,” or pneumonia, or tuberculosis, or any of the fevers. As soon as the fast begins, and the first hunger has been withstood, the secretions cease, and the whole assimilative system, which takes so much of the energies of the body, goes out of business. The body then begins a sort of house-cleaning, which must be helped by an enema and a bath daily, and, above all, by copious water-drinking. The tongue becomes coated, the breath and the perspiration offensive; and this continues until the diseased matter has been entirely cast out, when the tongue clears and hunger reasserts itself in unmistakable form.
Fasting and Weight
Now, you may ask: Can fasting help you lose weight?
Strange as it may seem, the fast is a cure for both emaciation and obesity. After a complete fast the body will come to its ideal weight. People who are very stout will not regain their weight; while people who are under weight may gain a pound or more a day for a month.
So fasting will help you reach your ideal weight, according to the author.
Next, he goes on with some more anecdotal material on how fasting has helped his wife and friends and thousands of readers who wrote in—the author became quite a celebrity on the subject of health and fasting. Fascinating!
While I skipped most of the anecdotes, I believe this excerpt from the book summarizes his enthusiasm quite well:
The reader may think that my enthusiasm over the fasting cure is due to my imaginative temperament; I can only say that I have never yet met a person who has given the fast a fair trial who does not describe his experience in the same way. I have never heard of any harm resulting from it, save only in cases of tuberculosis, in which I have been told by one physician that people have lost weight and not regained it.
I regard the fast as Nature’s own remedy for all other diseases. It is the only remedy which is based upon an understanding of the fundamental nature of disease. And I believe that when the glad tidings of its miracles have reached the people it will lead to the throwing of 90 per cent of our present materia medica into the waste-basket. This may be unwelcome to those physicians who are more concerned with their own income than they are with the health of their patients; but I personally have never met any such physicians, and so I most earnestly urge it upon medical men to investigate the extraordinary and almost incredible facts about the fasting cure.
Next, he goes over several anecdotes where readers of the author’s articles sent in some of their own positive experiences with fasting and how it helped them solve their health issues.
Even other medical doctors wrote in sharing their own supportive evidence of the benefits of fasting as observed in their own medical practices.
Water and Milk
While I don’t want to discuss possibly outdated implementation tactics on fasting — such as drinking lots of milk while doing it — here’s one that you cannot argue with:
One should drink all the water he possibly can while fasting, only not taking too much at a time. I take a glass full every hour, at least; sometimes every half hour.
And speaking of the suggested milk diet, the author did have mixed evidence of its benefits:
Also I tried on many occasions to take the milk diet after a short fast of three or four days, and always the milk has disagreed with me and poisoned me.
I take it as evidence that the concrete implementation of the fasting diet must be well-researched and you should read the latest research on it.
Fasting and Disease
Anyways, most implementations of fasting seems to be beneficial for your body’s long-term and sustainable well-being.
People ask me in what diseases I recommend fasting. I recommend it for all diseases of which I have ever heard, with the exception of one in which I have heard of bad results—tuberculosis.
The latter not being an issue in many parts of the developed world anymore (fortunately).
The diseases for which fasting is mos obviously to be recommended are all those of the stomach and intestines, which any one can see are directly caused by the presence of fermenting and putrefying food in the system. Next come all those complaints which are caused by the poisons derived from these foods in the blood and the eliminative organs: such are headaches and rheumatism, liver and kidney troubles, and of course all skin diseases. Finally, there are the fevers and infectious diseases, which are caused by the invasion of the organism by foreign bacteria, which are enabled to secure a lodgment because of the weakened and impure condition of the blood-stream. Such are the “colds” and fevers. In these latter cases nature tries to save us, for there is immediately experienced a disinclination on the part of the sick person to take any sort of food; and there is no telling how many people have been hurried out of life in a few days or hours, because ignorant relatives, nurses and physicians have gathered at their bedside and implored them to eat.
To summarize, this is the author’s view on the question: when is the best time to start fasting?
The fast is Nature’s remedy for all diseases, and there are few exceptions to the rule. When you feel sick, fast. Do not wait until the next day, when you will feel stronger, nor till the next week, when you are going away into the country, but stop eating at once.
Fasting as a Wage Slave
Can you fast if you are a “wage slave”, i.e., you work as an employee for an hourly or monthly rate, and you cannot stop?
- First, consider breaking free (e.g., by becoming a freelance developer working from home on their own business).
- Second, consider that you can still do fasting:
Many of the people who wrote to me were victims of our system of wage slavery, who wrote me that they were ill, but could not get even a few days’ release in which to fast. They wanted to know if they could fast and at the same time continue their work. Many can do this, especially if the work is of a clerical or routine sort. On my first fast I could not have done any work, because I was too weak. But on my second fast I could have done anything except very severe physical labor. I have one friend who fasted eight days for the first time, and who did all her own housework and put up several gallons of preserves on the last day. I have received letters from a couple of women who have fasted ten or twelve days, and have done all their own work. I know of one case of a young girl who fasted thirty-three days and worked all the time at a sanatorium, and on the twenty-fourth day she walked twenty miles.
Fasting Study on Small Data
Next, a very interesting “Symposium on fasting” presents the results of a questionnaire with 277 data points — not much in today’s age of research and big data.
So, I give only the quick list of diseases benefited from the fasting cure, according to the small study (take it with a grain of salt):
Following is the complete list of diseases benefited—45 of the cases having been diagnosed by physicians: indigestion (usually associated with nervousness), 27; rheumatism, 5; colds, 8; tuberculosis, 4; constipation, 14; poor circulation, 3; headaches, 5; anæmia, 3; scrofula, 1; bronchial trouble, 5; syphilis, 1; liver trouble, 5; general debility, 5; chills and fever, 1; blood poisoning, 1; ulcerated leg, 1; neurasthenia, 6; locomotor ataxia, 1; sciatica, 1; asthma, 2; excess of uric acid, 1; epilepsy, 1; pleurisy, 1; impaction of bowels, 1; eczema, 2; catarrh, 6; appendicitis, 3; valvular disease of heart, 1; insomnia, 1; gas poisoning, 1; grippe, 1; cancer, 1.
The Ideal Fasting Diet
But what is the ideal fasting diet? The author goes on to discuss this exact question.
The general rules are mostly of a negative sort. There are many kinds of foods, some of them most generally favored, of which one may say that they should never be used, and that those who use them can never be as well as they would be without them. Such foods are all that contain alcohol or vinegar; all that contain cane sugar; all that contain white flour in any one of its thousand alluring forms of bread, crackers, pie, cake, and puddings; and all foods that have been fried—by which I mean cooked with grease, whether that grease be lard, or butter, or eggs or milk. It is my conviction that one should bar these things at the outset, and admit of no exceptions. I do not mean to say that healthy men and women cannot eat such things and be well; but I say that they cannot be as well as they would be without them; and that every particle of such food they eat renders them more liable to all sorts of infection, and sows in their systems the seeds of the particular chronic disease that is to lay them low sooner or later.
A perfectly normal and well person is, under the artificial conditions of our bringing up, a very great rarity; and so we all have to regard ourselves as more or less diseased, and work towards the ideal of soundness. We must do this with intelligence—there is no short cut, no way to save one’s self the trouble of thinking.
Okay, and now here’s my own gold standard of a healthy diet: mainly fresh fruits. 🍌🍎🍓🫐
That’s super cheap, and it just has to be super healthy:
By way of setting an ideal, let me give you the example of a young lady who for six or seven months has been living in our home, and giving us a chance to observe her dietetic habits. This young lady three years ago was an anæmic school-teacher, threatened with consumption, and a victim of continual colds and headaches; miserable and beaten, with an exopthalmic goitre which was slowly choking her to death. She fasted eight days, and achieved a perfect cure. She is to-day bright, alert and athletic; and she lives on about twelve hundred calories of food a day—one half what I eat, and less than a third of the old-school dietetic standards. Occasionally she will eat nut butter, or sweet potato, or some whole wheat crackers with butter, or a dish of ice-cream; but at least ninety per cent of her food has consisted of fresh fruit. Meal after meal, day after day, I have seen her eat one or two bananas and two or three peaches, or say, a slice of watermelon or canteloupe; at some meals she will eat only the peaches, and then again she will eat nothing. A dollar a week would pay for all her food; and on this diet she laughs and talks, reads and thinks, walks and swims with my wife and myself—a kind of external dietetic conscience, which we would find it hard to get along without. And tell me, Dr. Woods Hutchinson, or other scoffer at the “food-faddists,” don’t you think that a case like this gives us some right to ask for patient investigation of our claims? Or will you stand by your pill boxes and your carving-knives and the rest of your paraphernalia, and compel us to cure all your patients in spite of you?
Speaking of fruits, let’s see what the book tells us about meat:
I am asked many questions as to my attitude toward the question of meat-eating. I was brought up on a diet of meat, bread and butter, potatoes, and sweet things. Four years ago when I found myself desperately run down, suffering from nervousness, insomnia, and almost incessant headaches, I came upon various articles written by vegetarians, and I began to suspect that my trouble might be due to meat. I went away on a camping-trip for several weeks, taking no meat with me, and because I found that I was a great deal better, I believed that the meat had been responsible for my trouble. I then visited the Battle Creek Sanitarium, and became familiar with all their arguments against meat, and thereafter I did not use it for three years. I called myself a vegetarian; but at the same time I realized that I differed from most vegetarians in some important particulars.
Well, nothing surprising here. Vegetarians were much more uncommon back in the old days. But now we know without a shadow of a doubt that vegatarians are healthier and live longer. It has been proven by many studies that a vegetarian diet is much healthier:
In most countries, vegetarian diets were associated with a lower intake of energy and saturated fat, and a better cardiovascular profile (lower body weight, LDL cholesterol levels, blood pressure, fasting glucose, and triglycerides) — Hargreaves et al. International Journal Environ Res Public Health
Here’s an interesting take from the book on contamination of meat:
There have been numerous expositions of the greater liability of meat to contamination. Dr. Kellogg, for instance, has purchased specimens of meat in the butcher-shops, and has had them examined under the microscope, and has told us how many hundreds of millions of bacteria to the gram have been discovered. This argument has a tendency to appal one; I know it had great effect upon me for a long time, and I took elaborate pains to take into my system only those kinds of food which were sterilized, or practically so. This is the health regimen which is advocated by Professor Metchnikoff; one should eat only foods which have been thoroughly boiled and sterilized. I have come, in the course of time, to the conclusion that this way of living is suicidal, and that there is no way of destroying one’s health more quickly. I think that the important question is, not how many bacteria there are in the food when you swallow it, but how many bacteria there come to be in food after it gets into your alimentary canal. The digestive juices are apparently able to take care of a very great number of germs; it is after the food has passed on down, and is lodged in the large intestine, that the real fermentation and putrefaction begin—and these count for more, in the question of health, than that which goes on in the butcher-shop or the refrigerator or the pantry
Is meat good for physical labor jobs?
I have been accustomed all my life to think of meat as a very “heavy” article of food, an article of food suited for men doing hard physical labor; it is a curious fact that the view I am setting forth here is precisely the opposite. So long as I am doing hard physical labor, whether it is walking ten miles a day, or playing tennis, or building a house, I get along perfectly upon the raw food; but when I settle down for long periods of thinking and writing—often sitting for six hours without moving from one position—I find that I need something else, and nothing has answered that purpose quite so well as beef-steak. It appears to be, so far as I am concerned, the most easily digested and most easily assimilated of foods. And because the work that I am doing seems to me to be important, I am willing to make the sacrifice of money and time and trouble which it necessitates. My diet at such times will consist of beef or chicken, shredded wheat biscuit, and a little fruit. If any one is disposed to follow my example and make this experiment, I beg to call his attention especially to the fact that I name these three kinds of food, and none others; and that I mean these three kinds and none others. The main trouble with advising anybody to eat meat is that he proceeds to eat it in the everyday world, where it means not the eating of broiled lean beef, but also of bacon and eggs, and of bread and butter, and of potatoes with cream gravy, and of rice pudding and crackers and cheese and coffee. Please do not proceed to eat these things and then hold meat-eating responsible for the consequences.
The book ends with a couple of articles and testimonials submitted by avid readers of the author. I think we can skip those safely because they are mostly anecdotical.
Fasting – Conclusion, Benefits, and How to Start
Let’s finish up this book summary about the fasting diet with the top benefits of fasting as reported by Healthline:
- Promotes Blood Sugar Control by Reducing Insulin Resistance
- Promotes Better Health by Fighting Inflammation
- May Enhance Heart Health by Improving Blood Pressure, Triglycerides and Cholesterol Levels
- May Boost Brain Function and Prevent Neurodegenerative Disorders
- Aids Weight Loss by Limiting Calorie Intake and Boosting Metabolism
- Increases Growth Hormone Secretion, Which Is Vital for Growth, Metabolism, Weight Loss and Muscle Strength
- Could Delay Aging and Extend Longevity
- May Aid in Cancer Prevention and Increase the Effectiveness of Chemotherapy
All of those are backed by science (see article referenced). The article also points out the most common ways to start fasting:
- Water fasting: Drinking only water
- Juice fasting: Drinking vegetable or or fruit juice
- Intermittent fasting: Limit your fasting period to a number of hours daily (e.g., 16 hours non-eating per day)
- Partial fasting: Eliminate certain foods such as processed foods or sugar or alcoholic beverages.
- Calorie restriction: Just eat fewer calories for a fixed time.
I personally prefer intermittent fasting as it can be integrated easily into your daily life and still has many of the benefits.
While working as a researcher in distributed systems, Dr. Christian Mayer found his love for teaching computer science students.
To help students reach higher levels of Python success, he founded the programming education website Finxter.com that has taught exponential skills to millions of coders worldwide. He’s the author of the best-selling programming books Python One-Liners (NoStarch 2020), The Art of Clean Code (NoStarch 2022), and The Book of Dash (NoStarch 2022). Chris also coauthored the Coffee Break Python series of self-published books. He’s a computer science enthusiast, freelancer, and owner of one of the top 10 largest Python blogs worldwide.
His passions are writing, reading, and coding. But his greatest passion is to serve aspiring coders through Finxter and help them to boost their skills. You can join his free email academy here.