John Yudkin
Born(1910-08-08)8 August 1910
London, England
Died12 July 1995(1995-07-12) (aged 84)
London, England
EducationBSc (London) 1929[citation needed]
BA (Cambridge) 1931
PhD (Cambridge) 1935
MB, BChir (Cambridge) 1938[citation needed]
MD (Cambridge) 1943[citation needed]
Alma materChrist's College, Cambridge
OccupationProfessor of Physiology, Queen Elizabeth College, London, 1945–1954.
Professor of Nutrition, Queen Elizabeth College, 1954–1971.[1]
Notable work
Pure, White and Deadly

John Yudkin FRSC (8 August 1910 – 12 July 1995) was a British physiologist and nutritionist, and the founding Professor of the Department of Nutrition at Queen Elizabeth College, London.

Yudkin wrote several books recommending low-carbohydrate diets for weight loss, including This Slimming Business (1958). He gained an international reputation for his book Pure, White and Deadly (1972), which warned that the consumption of sugar (sucrose, which consists of fructose and glucose) is dangerous to health, an argument he had made since at least 1957.[2][3] Specifically, he wrote that sugar consumption was a factor in the development of conditions such as dental caries, obesity, diabetes, and heart attack.[4]

Yudkin’s failure to incorporate possible confounding factors in his case-control designs was an area of heavy criticism at the time; apart from other unmeasured known risk factors that might affect cardiovascular disease (CVD), data had emerged soon after, suggesting that sugar intake was associated with smoking, a big risk factor for CVD.[5] Yudkin’s failure to account for confounding factors led to harsh words from Ancel Keys at the time.[6] From the late 2000s, there was a resurgence of interest in his work, following a 2009 YouTube video[7] about sugar and high-fructose corn syrup by the pediatric endocrinologist Robert Lustig, and because of increasing concern about an obesity epidemic and metabolic syndrome.[8][9][10] Pure, White and Deadly was republished in 2012, with a foreword by Lustig.[11]

Early life and education

Yudkin was raised in the East End of London in an Orthodox Jewish family that had fled the Russian pogroms of 1905. His father's death left six-year-old Yudkin and his four brothers to be raised by their mother in considerable poverty. He won scholarships to Hackney Downs School (formerly the Grocers' Company's School), and another from there to Chelsea Polytechnic.[1] After gaining his BSc degree in 1929 he briefly considered a career in teaching,[citation needed] but then discovered that he could sit an examination for a scholarship to the University of Cambridge. He matriculated at Christ's College, Cambridge as a scholar, and graduated in biochemistry at the age of 20 in 1931.

He worked for his PhD in the Department of Biochemistry at Cambridge under the supervision of Marjory Stephenson, a pioneer of research in bacterial metabolism, who funded his work.[1] His PhD thesis was on "adaptive enzymes" (subsequently termed "induced enzyme synthesis"). His account of the phenomenon inspired the research of Jacques Monod, who later worked out a detailed mechanism for the induction of enzymes in bacteria and was awarded the Nobel Prize for his work.[12]

In 1933 Yudkin married Milly Himmelweit, who had recently left Berlin to escape the worsening political situation. The marriage lasted until her death in March 1995. They had three sons, Michael (born 1938), Jonathan (1944–2012) and Jeremy (born 1948).

While pursuing his PhD research, Yudkin took up medical studies in 1934 and started teaching physiology and biochemistry to medical students,[1] first at Christ's College, then also at other colleges in Cambridge. He began clinical studies at The London Hospital in 1935, while continuing to teach in Cambridge one weekday and at weekends.


  • FRSC (1938)
  • MRCP (1946)
  • FIBiol (1958)
  • FRCP (1975)
  • Fellow of King's College, London (1971)
  • Honorary Fellow of the Hebrew University, Jerusalem (1993)

Yudkin completed his medical studies in 1938, and was appointed Director of Medical Studies at Christ's College. The same year, he started research at the Dunn Nutritional Laboratory in Cambridge, working principally on the effects of dietary vitamins.

His studies of the nutritional status of school children in Cambridge showed that supplementation of the diet with vitamins had little effect on their general health.[13] The studies also showed serendipitously that children from a poorer area of Cambridge were shorter and lighter, and had lower haemoglobin levels and a weaker grip, than those from a wealthier area. Moreover, children from three industrial towns in Scotland were, on average, inferior in the same four measurements to the average Cambridge child, and the children from the poorer families in the Scottish towns were inferior in these measurements to those from the wealthier families.[14]

These findings probably helped to persuade Yudkin that nutrition was not only a biological science but also had important social and economic components and implications. In 1942 he wrote an article in '’The Times'’ (published anonymously, as was customary in those days) pointing out that there were a large number of organisations in the UK concerned in some way with nutrition – the Ministry of Food, the Ministry of Health, the Medical Research Council, the Cabinet Advisory Board on Food Policy, etc. – but no single body responsible for formulating a uniform plan for nutrition. What was needed was a UK Nutrition Council with oversight of food policy.[15] The suggestion fell on deaf ears.

During the Second World War, Yudkin served in the Royal Army Medical Corps and was posted to Sierra Leone. While there he studied a skin disease that was prevalent among local African soldiers and discovered that it was due not to an infection, as had been believed, but to riboflavin deficiency.[16] He found that the Army had devised a uniform diet for its soldiers in the four British West African colonies (Gambia, Sierra Leone, Gold Coast and Nigeria). This diet was, on paper, adequate in all nutrients – including riboflavin, which was supplied predominantly from millet. But it turned out that millet, although a staple in the Gold Coast and Nigeria, was loathed by soldiers from Sierra Leone, who would not eat it even if they were hungry.[17] This experience must have brought home to Yudkin the importance of custom and upbringing in determining a person's choice of foods.

In 1945, shortly after the end of the war, he was elected to the Chair of Physiology at Queen Elizabeth College in London (then the King's College of Household and Social Science). Over the next several years, under his leadership, the college and the University of London established a BSc degree in nutrition[1] (the first degree in nutrition in any European university).[citation needed] Students were taught an integrated series of courses including not only chemistry, physics and biology but also relevant elements of demography, sociology, economics and psychology. The first students were admitted in 1953, and in 1954 the Department of Nutrition was officially opened and Yudkin's Chair was converted into a Professorship of Nutrition. During the following years the Department won an international reputation not only for the strength of its research in the physiological and biochemical aspects of the subject, but also for work in such topics as nutrition in the elderly, food surveys in defined populations and the psychology of food choice, and it attracted numerous students from outside the UK, many of them from developing countries.

Yudkin's publications from the Department showed an unusual breadth of interests, including (in addition to biochemistry) further studies of adaptive enzymes,[18][19] nutrition and public health,[20] diseases of affluence,[21][22] food choice both in human beings[23][24] and in experimental animals,[25] and historical aspects of the human diet.[26][27] But his concern became increasingly focused on two topics: the treatment of overweight and the harmful effects of excessive sugar (sucrose) consumption.

The end of food rationing early in the 1950s brought with it an increase in the number of people who were suffering from obesity, and by 1958 slimming diets had proliferated, many of them with no scientific basis. Yudkin showed that in most patients weight could be well controlled by restricting dietary carbohydrate.[28] '’This Slimming Business'’ (1958), which expressed this idea in user-friendly language, proved popular: it was republished in paperback in 1962, reached its fourth edition in 1974, reappeared as ‘’Lose Weight, Feel Great’’ in the USA, was translated into Dutch and Hungarian, and spawned ‘’The Slimmer’s Cook Book’’ in 1961 and ‘’The Complete Slimmer’’ in 1964.

Yudkin’s interest in sugar arose indirectly from his studies of the alarming increase in many countries during the first half of the twentieth century in the incidence of coronary thrombosis. This increase was of great concern to health professionals, and it was widely attributed to an increase in the amount of fat, or of a particular type of fat, in the diet. In a paper published in 1957[2] Yudkin analysed diets and coronary mortality in different countries for the year 1952, and also analysed trends in diet, and trends in coronary mortality, in the UK between 1928 and 1954. The first of these analyses produced no evidence for the view that total fat, or animal fat, or hydrogenated fat, was the direct cause of coronary thrombosis; in fact the closest relationship between coronary deaths and any single dietary factor was with sugar. The second analysis, that of historical trends in the UK, found no good relationship with any single dietary factor. Instead, it suggested that some change or changes in lifestyle during the past several decades was contributing to the increased incidence of coronary deaths. One obvious change was reduced exercise, and another was alterations in diet.

Given the dramatic increase in sugar consumption during the first half of the century, Yudkin started to suspect that excessive sugar in the diet might contribute not only to obesity but also to coronary heart disease. Studying historical data from many different countries, he found that increasing prosperity leads to an increase in sugar consumption, particularly in manufactured foods, and also that the ready availability of sugar-containing manufactured foods even in the poorer countries may lead to their being bought in preference to more nutritious food.[4] In 1964 he wrote 'In the wealthier countries, there is evidence that sugar and sugar-containing foods contribute to several diseases, including obesity, dental caries, diabetes mellitus and myocardial infarction [heart attack]'.[4] Investigating whether any link between sugar consumption and disease could be shown in individual patients, he and his associates in the Department of Nutrition found that patients with atherosclerotic disease (a frequent precursor of coronary heart disease) consumed significantly more sucrose than control patients.[29]

An obstacle to the acceptance of these ideas was the belief at the time that sugar and starch were metabolised in the same way, so that one would expect no difference in their effects. Yudkin and his associates, however, fed both experimental animals and human volunteers with differing quantities of sugar and starch, and found major differences between the two carbohydrates in their metabolic effects.[30][31] Unlike his colleague Thomas L. Cleave, Yudkin believed sugar was more harmful than refined grains and refused to use the term "refined carbohydrates" because it gave "the impression that white flour has the same ill effects as sugar".[32] As early as 1967 Yudkin suggested that the excessive consumption of sugar might result in a disturbance in the secretion of insulin, and that this in turn might contribute to atherosclerosis and diabetes.[33]

Pure, White and Deadly

Main article: Pure, White and Deadly


Yudkin's Pure, White, and Deadly (1972) was written for a lay readership. Its intention was to summarise the evidence that the consumption of sugar was leading to a greatly increased incidence of coronary thrombosis; that it was certainly involved in dental caries, probably involved in obesity, diabetes and liver disease, and possibly involved in gout, dyspepsia and some cancers. The book drew on studies from Yudkin's own department and other biochemical and epidemiological research in the UK and elsewhere. Pure, White and Deadly was extremely successful. It appeared as Sweet and Dangerous in the USA, and was translated into Finnish, German, Hungarian, Italian, Japanese and Swedish. A revised and expanded edition was published in 1986.

The last paragraph of Chapter 1 begins "I hope that when you have read this book I shall have convinced you that sugar is really dangerous." The message was extremely unwelcome to the sugar industry and manufacturers of processed foods. These firms employed a number of methods to impede Yudkin's work. The final chapter of Pure, White and Deadly lists several examples of attempts to interfere with the funding of his research and to prevent its publication. It also refers to the rancorous language and personal smears that Ancel Keys — the American epidemiologist who had proposed that saturated fat was the primary cause of heart disease — employed to dismiss the evidence that sugar was the true culprit. Keys wrote, for example:

It is clear that Yudkin has no theoretical basis or experimental evidence to support his claim for a major influence of dietary sucrose in the etiology of CHD; his claim that men who have CHD are excessive sugar eaters is nowhere confirmed but is disproved by many studies superior in methodology and/or magnitude to his own; and his "evidence" from population statistics and time trends will not bear up under the most elementary critical examination. But the propaganda keeps on reverberating ...[34][35]

The efforts of the food industry to discredit the case against sugar were largely successful, and by the time of Yudkin’s death in 1995 his warnings were, for the most part, no longer being taken seriously.[11] Despite the criticism that he had "no theoretical basis" to support his claims,[34] following a successful publication of his book in America, the McGovern Guidelines for US dietary goals recommended, in 1977, a reduction in sugar intake "by 40 percent,"[36] and the US-published guidelines in 1980 prominently advised "don't eat too much sugar."[37]


In 2009 Robert Lustig, a pediatric endocrinologist of the University of California, San Francisco, with a special interest in childhood obesity, made a video, Sugar: The Bitter Truth.[8] Lustig and his colleagues had discovered, independently of Yudkin's work, that sugar has serious deleterious effects, particularly in the etiology of diabetes and obesity. In his video, Lustig referred to his re-discovery of and admiration for Yudkin's research. The popularity of the video, which has been viewed several million times, has contributed to a resurgence of interest in Yudkin's research.[11]

Pure, White and Deadly was republished in 2012, 40 years after its first appearance, with an introduction by Lustig, and subsequently translated into German and Korean. Articles on Yudkin's work, and the way in which the food industry denigrated and obstructed his research, have appeared in the lay press[9][38][39] and in television programmes in the UK, Australia and Canada. His arguments and evidence for the dangers of sugar were the focus of several articles in the British Medical Journal on 19 January 2013.[10]

Later life

Yudkin retired from his Professorship in 1971 and left the College in 1974. He continued to write research papers and books. This Nutrition Business appeared in 1976 (and was later translated into Spanish), A–Z of Slimming in 1977, Eat Well, Slim Well in 1982, The Penguin Encyclopedia of Nutrition in 1985 (later translated into French), and The Sensible Person's Guide to Weight Control in 1990. He also continued to write popular articles in lay magazines, having by now become a household name. Having been interested in Israel for many years – soon after its foundation in 1948 he had been asked to advise on the nutritional problems experienced by the new state – he continued in his retirement as an active Governor of the Hebrew University of Jerusalem. He also began to collect antiquarian books, specialising in medicine, nutrition and the culinary arts; after his death much of his collection was given to the National Library of Israel, Jerusalem. He died in London on 12 July 1995.[citation needed]

Selected works

Books by John Yudkin alone

Books written or edited by Yudkin and others

See also


  1. ^ a b c d e Davies, Louise (24 July 1995). "Obituary: John Yudkin", The Independent.
  2. ^ a b John Yudkin (27 July 1957). "Diet and coronary thrombosis hypothesis and fact". The Lancet. 270 (6987): 155–162. doi:10.1016/S0140-6736(57)90614-1. ISSN 0140-6736. PMID 13450357. Wikidata Q56852868.
  3. ^ For sucrose, "Sucrose", PubChem, National Center for Biotechnology Information.
  4. ^ a b c John Yudkin (1 January 1964). "Patterns and trends in carbohydrate consumption and their relation to disease". Proceedings of the Nutrition Society. 23 (02): 149–162. doi:10.1079/PNS19640028. ISSN 0029-6651. PMID 14189103. Wikidata Q56852869.
  5. ^ [1] "sugar consumption and cigarette smoking"
  6. ^ Ancel Keys (1 September 1971). "Sucrose in the diet and coronary heart disease". Atherosclerosis. 14 (2): 193–202. doi:10.1016/0021-9150(71)90049-9. ISSN 0021-9150. PMID 4940760. Wikidata Q34224041.
  7. ^ Sugar: The Bitter Truth on YouTube
  8. ^ a b Lustig, Robert H. (July 2009). Sugar: The Bitter Truth on YouTube. University of California Television.
  9. ^ a b Taubes, Gary (13 April 2011). Is Sugar Toxic?, The New York Times.
  10. ^ a b Geoff Watts (15 January 2013). "Sugar and the heart: old ideas revisited". The BMJ. 346: e7800. doi:10.1136/BMJ.E7800. ISSN 0959-8138. PMID 23321487. S2CID 26350998. Wikidata Q34322738.
  11. ^ a b c Leslie, Ian (7 April 2016). "The sugar conspiracy". The Guardian.
  12. ^ Monod, Jacques (11 December 1965). "Nobel Lecture: From Enzymatic Adaption to Allosteric Transitions" (PDF). Nobel Media AB. p. 1.
  13. ^ John Yudkin (12 August 1944). "Nutritional Status of Cambridge School-children". The BMJ. 2 (4362): 201–205. doi:10.1136/BMJ.2.4362.201. ISSN 0959-8138. PMC 2286012. PMID 20785586. Wikidata Q56852870.
  14. ^ Yudkin, John (16 September 1944). "The Nutritional Status of Children and Mothers of Industrial Towns". The Medical Officer.
  15. ^ Anonymous (28 August 1942). "Food and Food Values". The Times.
  16. ^ Yudkin, John (October–November 1946). "Riboflavin Deficiency in the West African Soldier". Journal of Tropical Medicine and Hygiene. 49 (5): 83–87. PMID 20281466.
  17. ^ Yudkin, John (1946). "Some Observations on Nutrition in the West African Soldier". Nutrition, Dietetics, Catering (Spring and Summer): 1–4.
  18. ^ Joel Mandelstam; John Yudkin (August 1952). "Studies in biochemical adaptation. The effect of variation in dietary protein upon the hepatic arginase of the rat". Biochemical Journal. 51 (5): 681–6. doi:10.1042/BJ0510681. ISSN 0264-6021. PMC 1197916. PMID 13018145. Wikidata Q24531315.
  19. ^ Joel Mandelstam; John Yudkin (August 1952). "Studies in biochemical adaptation. Some aspects of galactozymase production by yeast in relation to the mass action theory of enzyme adaptation". Biochemical Journal. 51 (5): 686–93. doi:10.1042/BJ0510686. ISSN 0264-6021. PMC 1197917. PMID 13018146. Wikidata Q24531318.
  20. ^ Yudkin, John (November 1964). "Nutrition Education: For Whom and By Whom?". Home Economics: 16–19.
  21. ^ John Yudkin (1 November 1963), Nutrition in the Affluent Society, vol. 99, pp. 579–586, PMID 14079869, Wikidata Q76606875
  22. ^ John Yudkin (1 October 1965). "Evolution, history, and nutrition: their bearing on oral disease and other diseases of civilization". The Dental practitioner and dental record. 16 (2): 60–64. ISSN 0011-8729. PMID 5214376. Wikidata Q34229685.
  23. ^ John Yudkin (1 May 1956). "Man's choice of food". The Lancet. 270 (6924): 645–649. doi:10.1016/S0140-6736(56)90687-0. ISSN 0140-6736. PMID 13320834. Wikidata Q56852871.
  24. ^ John Yudkin (1 June 1963). "Nutrition and palatability with special reference to obesity, myocardial infarction, and other diseases of civilisation". The Lancet. 1 (7295): 1335–1338. doi:10.1016/S0140-6736(63)91920-2. ISSN 0140-6736. PMID 14002890. Wikidata Q56852872.
  25. ^ Melek Khairy; T. B. Morgan; John Yudkin (1 January 1963). "Choice of diets of differing caloric density by normal and hyperphagic rats". British Journal of Nutrition. 17: 557–568. doi:10.1079/BJN19630058. ISSN 0007-1145. PMID 14083954. Wikidata Q34255883.
  26. ^ T.C. Barker, J.C. McKenzie and John Yudkin (1966). Our Changing Fare. London: MacGibbon and Kee. pp. 150–159.
  27. ^ Oddy, D.J.; J. Yudkin (1968). "An Evaluation of English Diets of the 1860s". Proceedings of the Nutrition Society. 28: 13A.
  28. ^ John Yudkin (1 December 1959). "The causes and cure of obesity". The Lancet. 274 (7112): 1135–1138. doi:10.1016/S0140-6736(59)90116-3. ISSN 0140-6736. PMID 13846696. Wikidata Q56852873.
  29. ^ John Yudkin; Janet Roddy (1 July 1964). "Levels of dietary sucrose in patients with occlusive atherosclerotic disease". The Lancet. 2 (7349): 6–8. doi:10.1016/S0140-6736(64)90003-0. ISSN 0140-6736. PMID 14149219. Wikidata Q56852874.
  30. ^ al-Nagdy S; Miller DS; Qureshi RU; John Yudkin (1 January 1966). "Metabolic differences between starch and sucrose". Nature. 209 (5018): 81–82. Bibcode:1966Natur.209...81A. doi:10.1038/209081A0. ISSN 1476-4687. PMID 5927230. S2CID 4187732. Wikidata Q34241964.
  31. ^ Akinyanju PA; Qureshi RU; Salter AJ; John Yudkin (1 June 1968). "Effect of an "atherogenic" diet containing starch or sucrose on the blood lipids of young men". Nature. 218 (5145): 975–977. Bibcode:1968Natur.218..975A. doi:10.1038/218975A0. ISSN 1476-4687. PMID 5681247. S2CID 4215023. Wikidata Q34237790.
  32. ^ Scrinis, Gyorgy (2013). Nutritionism: The Science and Politics of Dietary Advice. Columbia University Press. p. 84.
  33. ^ Yudkin, John (1967). Chemistry, Medicine and Nutrition: Symposium held in Bristol on 14–15 April, 1966. London: Royal Institute of Chemistry. pp. 33–44.
  34. ^ a b Ancel Keys (1 September 1971). "Sucrose in the diet and coronary heart disease". Atherosclerosis. 14 (2): 193–202. doi:10.1016/0021-9150(71)90049-9. ISSN 0021-9150. PMID 4940760. Wikidata Q34224041.
  35. ^ Ancel Keys (1 September 1975). "Coronary heart disease--the global picture". Atherosclerosis. 22 (2): 149–192. doi:10.1016/0021-9150(75)90001-5. ISSN 0021-9150. PMID 1103902. Wikidata Q33922147.
  36. ^ US Senate Select Committee on Nutrition and Human Needs (February 1977). "Dietary Goals for the United States" (PDF).
  37. ^ "Nutrition and Your Health" (PDF). Home and Garden Bulletin. US Department of Agriculture. February 1980.
  38. ^ Rumbelow, Helen (9 January 2014). "Sugar: The Bitter Truth". The Times.
  39. ^ Llewellyn Smith, Julia (17 February 2014). "John Yudkin: The Man Who Tried to Warn Us About sugar". The Daily Telegraph. Archived from the original on 18 February 2014.