William Banting was a fashionable London undertaker who made the Duke of Wellington’s coffin. He was a prosperous, intelligent man but terribly fat. In August 1862, he was 66 years old and weighed 92 kg.  He stood only 1.65m in his socks. No pictures of him are available today, but he must have been nearly spherical. He was so overweight that he had to walk downstairs backwards to avoid jarring his knees and he was unable to do up his own shoe laces. His obesity made him acutely miserable.

For many years he passed from one doctor to another in a vain attempt to get his weight off. Many of the doctors he saw were both eminent and sincere. They took his money but they failed to make him thinner.

He tried every kind of remedy for obesity: Turkish baths, violent exercise, spa treatment, drastic dieting, many of the treatments made him gain. At length, because he thought he was going deaf, he went to an ear, nose and throat surgeon called William Harvey. This remarkable man saw at once that Banting’s real trouble was obesity, not deafness, and put him on an entirely new kind of diet. By Christmas 1862 he was down to 84kg. The following August he weighed a mere 71 kg – nearly right for his height and age.

In less than a year he had lost nearly 23kg and 300 mm off his waist line. He could put his old suits on over the new ones he had to order from his tailor. Naturally, Banting was delighted. He would gladly have gone through purgatory to reach his normal weight but, in fact, Mr Harvey’s diet was so liberal and pleasant that Banting ate as well while he was reducing as he had ever done before. What was the diet which performed this miraculous reduction? We have Banting’s own word for it, in his little book Letter on Corpulence, published in 1864.

Here is what he ate and drank:

BREAKFAST: Four or five ounces of beef, mutton, kidneys, broiled fish, bacon or cold meat of any kind except pork. One small biscuit or one ounce of dry toast. A large cup of tea without milk or sugar.

LUNCH: Five or six ounces of any fish except salmon, any meat except pork, any vegetable except potato. Any kind of poultry or game. One ounce of dry toast. Fruit. Two or three glasses of good claret, sherry or Cadeira. (Champagne, port and beer were forbidden.)

TEA: Two or three ounces of fruit. A rusk or two. A cup of tea without milk or sugar.

SUPPER: Three or four ounces of meat or fish as for lunch. A glass of Claret, or two.

NIGHT CAP: (If required): A tumbler of grog (Gin, Whisky or Brandy with water but no sugar) or two of Claret or Sherry.

In terms of calories this diet adds up to the astonishing figure of 2 800. An average modern low calorie reducing diet allows a meager 1 000 calories a day. Incidentally, there is no particular reason why salmon and pork should be excluded, except for the imprecise knowledge of the chemical composition of foods in the mid-nineteenth century. Certainly, there is no need for the overweight person to avoid them now. There must therefore have been something other than calorie reduction responsible for Banting’s weight loss. What was the secret?

In his own words:  “I can now confidently say that quantity of diet may be safely left to the natural appetite; and that it is the quality only which is essential to abate and cure corpulence. The diet was made up almost entirely of protein, fat, alcohol and fibre, with of course, the vitamins and mineral salts contained in these foods. Mr Harvey, who designed it, had realized that it is carbohydrate (starch and sugar ) which fattens fat people.”

This is the simple fact which explains Banting’s highly satisfactory weight reduction on a high-calorie low-carbohydrate diet. Perhaps it was too simple, for in spite of the excellent book which he published at his own expense and in which he gave all the credit to his doctor, William Harvey, contemporary doctors refused to believe it. The public, particularly those who were overweight, were impressed however and many people followed his diet successfully.

Banting’s name passed into the language as a synonym for slimming. But the principles of his successful diet were not understood in the 1860s and he and his doctor were ridiculed by the medical profession. To appreciate just how remarkable it was for Mr Harvey to have designed this revolutionary and successful treatment for Banting’s obesity, it is necessary to know something of the medical opinions at the time. In 1850 the medical profession in Europe had accepted the theory of a German chemist, Baron Justun von Liebig (1803-73), that carbohydrate and fat supplied the carbon which combined with oxygen in the lungs to produce body heat.

In terms of this theory, carbohydrate and fat were “respiratory foods” and the cause of obesity was believed to be an overindulgence of these: or as contemporary phraseology had it: “For the formation of body fat it is necessary that the materials be digested in greater quantity than is necessary to supply carbon to the respiration.”

The principle of the treatment of obesity based on this theory was to cut off as far as possible the supply of food, especially dietary fat, and to accomplish this, the patient was exhorted to establish an hourly watch over the instinctive desires, i.e. was subjected to semi-starvation. William Wadd had already advocated such methods and right down to today, doctors have gone on slavishly copying them in spite of the mounting evidence that they were unsatisfactory, at least from the patient’s point of view, if not from the physicians.

With this background of medical indoctrination on the subject of obesity to which many doctors have succumbed since, with far less excuse, William Harvey went to Paris in 1856 and attended the lectures of Claude Bernard (1813-1878), the great French physiologist. He heard Bernard expound his theory that the liver made not only bile but also a peculiar substance related to starches and sugars, to which the name glucose had been given. Relating this new idea to the already well known ones, “that a saccharine and farinaceous diet is used to fatten certain farm animals”, and “that a purely animal diet greatly assists in checking the secretion of diabetic urine”.

Harvey did some original and constructive thinking. This is how he put it:

That excessive obesity might be allied to diabetes as to its cause, although widely diverse in its development; and that if a purely animal diet were useful in the latter disease, a combination of animal food with such vegetable diet as contained neither sugar nor starch, might serve to arrest the undue formation of fat. In Harvey’s time, biochemistry was in its infancy and physiology was only just emerging from the shadow of the Middle Ages, so he could not explain his theory of altered carbohydrate metabolism in exact chemical terms. But he could test it out in practice and it was at this point, in 1862, that William Banting consulted him.

The history of William Harvey and his patient is interesting. It shows how social and economic influences and the desire to run with the herd, which is in all of us, can cloud scientific discoveries with compromise and in bringing them into line with orthodoxy can rob them of all practical value.

Banting published his Letter on Corpulence in 1864, privately, because he feared, not without reason as it turned out, that the Editor of the Lancet, to whom he first thought of submitting it, would refuse to publish anything “from an insignificant individual without some special introduction”. The same sort of objection deterred him from sending it to the Cornhill Magazine, which had recently carried an article, “What is the cause of obesity?” which in Banting’s view was not altogether satisfactory.

Banting’s pamphlet attracted immediate attention and was widely circulated. The treatment he described was phenomenally successful. The Banting diet then became the centre of bitter controversy. No one could deny that the treatment was effective but having first appeared in a publication by a layman, the medical profession, which was just beginning to climb the social ladder and was very much on its frock-coated dignity, felt bound to attack it.

The diet was criticized as being freakish and unscientific. Harvey came in for ridicule and vituperation and his practice as a surgeon began to suffer. But the obvious practical success of the high-fat high-protein low-carbohydrate diet called for some explanation from the doctors, and this was supplied by Dr Felix von Niemeyer of Stuttgart.

Basing his argument on the teachings of Leibig, Niemeyer explained Banting’s diet as follows: Protein foods are not converted to body fat, but the respiratory foods, fat and carbohydrate, are. He interpreted meat as lean meat and described the diet in terms which today would mean that it was a high-protein low-calorie diet with fat and carbohydrate both restricted. Of course the diet which actually slimmed Banting was not like that at all. It was a high-fat high-protein unrestricted calorie diet with only carbohydrate restricted.

Dr Niemeyer had effectively turned Banting’s diet upside down and the day was saved for the pundits. Niemeyer’s explanation was eagerly accepted and modified Banting’s diet, based upon this phony explanation, found their way into the text books for the rest of the nineteenth century. While all this rationalization of his diet was going on, William Harvey was feeling the cold draught of unpopularity with his colleagues and nine years after the publication of Banting’s pamphlet he publicly recanted.

He came into line with Dr Niemeyer and explained apologetically. He was able to continue his peaceful career as a respected ear, nose and throat surgeon. But Banting stuck to his guns and in 1875 published letters showing that obese people lost weight effectively and painlessly through eating large quantities of fat meat. In spite of an almost total lack of scientific knowledge of the chemical composition of different foods, Banting remained true to the principle William Harvey had taught him. He kept his weight down without difficulty and lived in physical comfort to the age of 81. His diet was so well known that his name became synonymous with dieting; people weren’t dieting; they were banting. In America, Banting’s meat diet led to the development of the American Salisbury steak, a staple of life in the late 1800s. Among the many diets which followed the publication of Banting’s pamphlet, every variation of the three main foods was tried but always with restriction of the total intake.

It seemed that in spite of the real value of Harvey’s observations and Banting’s application of them, nutritionists could not bring themselves to abandon the idea that to lose weight one must eat less. The principle derived from the law of conservation of energy (what comes out must go in) on the basis of which it was deduced that the energy intake (consumption of food) must exceed the energy expenditure when obesity is developing.

Of course this is perfectly obvious. A person can’t get fat unless he eats more food than he uses up for energy. But it is beside the point. The real question that needs answering about obesity is: What is the cause of the fat man’s failure to use up as much energy as he takes in as food? It could be that he is just greedy and eats more than he requires. It could also be that although he only eats a normal amount, some defect in the way his body deals with food deflects some of what he eats to his fats stores and keeps it there instead of letting him use it up as energy.

Popular books on slimming became mainly concerned with tricks for persuading people to eat less while seeming to allow them to eat more. In 1930, in the Journal of Clinical Investigation, the matter was summed up as:  “Obesity is never directly caused by abnormal metabolism but is always due to food habits not adjusted to the metabolic requirements;” i.e. over-weight never comes from a defective ability to mobilize fat from the fat stores but always from over-eating. This appeared to be the last word and doctors and slimming experts all over the world settled down to trying to persuade their obese patients to eat less.

Then in 1956, Prof. Alan Kekwick and Dr G.L.S. Pawan published the results of a scientific evaluation of Banting’s diet undertaken in their wards at their respective hospitals in London. They proved that Banting was right, by concluding: “The composition of the diet can alter the expenditure of calories in obese persons, increasing it when fats and proteins are given and decreasing it when carbohydrates are given.” This work had considerable impact on medical opinion and was widely mentioned in the press. Here is a quotation from the American Journal, Antibiotic Medicine and Clinical Therapy: Kekwick and Pawan from the Middlesex Hospital, London, report some news for the obese. All of the obese subjects studied lost weight immediately after admission to hospital and therefore a period of stabilization was required before commencing investigation. If the proportions of fat, carbohydrate and protein were kept constant, the rate of weight loss was then proportional to the calorie intake. If the calorie intake was kept constant, however, at 1 000 per day, the most rapid weight loss was noted with high fat diets… But when the calorie intake was raided to 2 600 daily in these patients, weight loss would still occur provided that this intake was given mainly in the form of fat and protein. It is concluded that from 30 to 50% of weight loss is derived from the total body water and the remaining 50 to 70% from the body fat.

In other words, doctors now have scientific justification for basing diets for obesity on reduction of carbohydrate rather than on reduction of calories and fat. Before going on it should be explained that Banting did in fact take some carbohydrate. Kekwick and Pawan and other investigators have shown that up to 60 g of carbohydrate a day are compatible with effective weight reduction on a high-fat, high-protein diet, although in some subjects even this amount will slow down the rate of weight loss. In such cases further restriction of carbohydrate with stricter adherence to the high-fat, high-protein foods results in satisfactory weight loss again.

Kekwick and Pawan went on further in publishing a report showing that the type of food eaten influences the rate of fat mobilization from the fat organ, and they went on to investigate the various hormones known to increase the liberation of free fatty acid (the form in which fat circulates in the blood and supplies energy) from adipose tissue. They found that adrenaline, corticotrophin and growth hormone did this and they began looking at a substance extracted from the urine of fasting subjects, to which the name Fat Mobilizing Substance (FMS) has been given. In 1960, The British Medical Journal published as its main article Kekwick’s Bradshaw lecture to the Royal College of Physicians. It was entitled “On Adiposity”, and gave an account of all the research on obesity up to that time. In it he referred to Fat Mobilizing Substance and gave a table of the conditions governing its appearance in human urine and another showing the effects of injecting it into mice. It was concluded that people fasting or taking mainly fat and protein, produce this hormone from their pituitary glands and that in mice it mobilizes stored fat and causes weight loss. People taking a normal, mixed carbohydrate-rich diet do not produce it nor do they make any on a low-calorie intake consisting mainly of carbohydrate. People with poor pituitary function do not make it either. It could be a very important hormone in the control of obesity, once it has been purified and made available for prescription, but it is likely to be expensive.

During that same time-period more and more physicians studied and wrote extensively of the merits of the restricted-carbohydrate diet namely professor of nutrition at Queen Elizabeth College, London University; Dr. John Yudkin (1910-1995). He published papers on restricted-carbohydrate dieting from both a scientific and a natural history perspective in most of the prestigious medical journals during a career spanning six decades. The three most popular diet books in America in recent years were all written by physicians detailing their own versions of the restricted-carbohydrate diet.

Dr. Irwin Stillman published his Quick Weight Loss Diet in 1967, describing how he overcame middle-aged obesity and a heart attack by cutting carbohydrates and drinking large quantities of water.

Dr. Robert Atkins wrote his first multimillion-copy-best-seller  Dr. Atkins Diet Revolution in 1972, detailing his own experiences as well as those of his many patients with low-carbohydrate dieting. In 1992 and in 2002 there was an updated version on the first book, published in 1972. The book made a greater impact than anyone might have predicted. Its sales exceeded ten million copies, in 1992 alone. It was the number one-selling diet book in America for nearly five years. In fact, it has been the all-time top seller in its field. In 1979 Dr. Herman Tarnower explained his approach to low-carbohydrate dieting with his cardiology and internal medicine patients in The Complete Scarsdale Medical Diet. Why are they so popular? Because the diet works.