Walter C. Willett
Primary Faculty

Walter C. Willett

Professor of Epidemiology and Nutrition


Other Positions

Faculty Affiliate in the Department of Epidemiology


Harvard T.H. Chan School of Public Health


Walter C. Willett, M.D., Dr. P.H., is Professor of Epidemiology and Nutrition at Harvard T.H. Chan School of Public Health. Dr. Willett studied food science at Michigan State University, and graduated from the University of Michigan Medical School before obtaining a Masters and Doctorate in Public Health from Harvard T.H. Chan School of Public Health. Dr. Willett has focused much of his work over the last 40 years on the development and evaluation of methods, using both questionnaire and biochemical approaches, to study the effects of diet on the occurrence of major diseases. He has applied these methods starting in 1980 in the Nurses' Health Studies I and II and the Health Professionals Follow-up Study. Together, these cohorts that include nearly 300,000 men and women with repeated dietary assessments, are providing the most detailed information on the long-term health consequences of food choices.

Dr. Willett has published over 2,000 original research papers and reviews, primarily on lifestyle risk factors for heart disease, cancer, and other conditions and has written the textbook, Nutritional Epidemiology, published by Oxford University Press, now in its third edition. He also has written four books for the general public. Dr. Willett is the most cited nutritionist internationally. He is a member of the National Academy of Medicine of the National Academy of Sciences and the recipient of many national and international awards for his research.


BMI and breast cancer risk around age at menopause.

Von Holle A, Adami HO, Baglietto L, Berrington de Gonzalez A, Bertrand KA, Blot W, Chen Y, DeHart JC, Dossus L, Eliassen AH, Fournier A, Garcia-Closas M, Giles G, Guevara M, Hankinson SE, Heath A, Jones ME, Joshu CE, Kaaks R, Kirsh VA, Kitahara CM, Koh WP, Linet MS, Park HL, Masala G, Mellemkjaer L, Milne RL, O'Brien KM, Palmer JR, Riboli E, Rohan TE, Shrubsole MJ, Sund M, Tamimi R, Tin Tin S, Visvanathan K, Vermeulen RC, Weiderpass E, Willett WC, Yuan JM, Zeleniuch-Jacquotte A, Nichols HB, Sandler DP, Swerdlow AJ, Schoemaker MJ, Weinberg CR.

Cancer Epidemiol. 2024 Apr. 89:102545. PMID: 38377945

Differences in polygenic score distributions in European ancestry populations: implications for breast cancer risk prediction.

Yiangou K, Mavaddat N, Dennis J, Zanti M, Wang Q, Bolla MK, Abubakar M, Ahearn TU, Andrulis IL, Anton-Culver H, Antonenkova NN, Arndt V, Aronson KJ, Augustinsson A, Baten A, Behrens S, Bermisheva M, de Gonzalez AB, Bialkowska K, Boddicker N, Bodelon C, Bogdanova NV, Bojesen SE, Brantley KD, Brauch H, Brenner H, Camp NJ, Canzian F, Castelao JE, Cessna MH, Chang-Claude J, Chenevix-Trench G, Chung WK, Colonna SV, Couch FJ, Cox A, Cross SS, Czene K, Daly MB, Devilee P, Dörk T, Dunning AM, Eccles DM, Eliassen AH, Engel C, Eriksson M, Evans DG, Fasching PA, Fletcher O, Flyger H, Fritschi L, Gago-Dominguez M, Gentry-Maharaj A, González-Neira A, Guénel P, Hahnen E, Haiman CA, Hamann U, Hartikainen JM, Ho V, Hodge J, Hollestelle A, Honisch E, Hooning MJ, Hoppe R, Hopper JL, Howell S, Howell A, Jakovchevska S, Jakubowska A, Jernström H, Johnson N, Kaaks R, Khusnutdinova EK, Kitahara CM, Koutros S, Kristensen VN, Lacey JV, Lambrechts D, Lejbkowicz F, Lindblom A, Lush M, Mannermaa A, Mavroudis D, Menon U, Murphy RA, Nevanlinna H, Obi N, Offit K, Park-Simon TW, Patel AV, Peng C, Peterlongo P, Pita G, Plaseska-Karanfilska D, Pylkäs K, Radice P, Rashid MU, Rennert G, Roberts E, Rodriguez J, Romero A, Rosenberg EH, Saloustros E, Sandler DP, Sawyer EJ, Schmutzler RK, Scott CG, Shu XO, Southey MC, Stone J, Taylor JA, Teras LR, van de Beek I, Willett W, Winqvist R, Zheng W, Vachon CM, Schmidt MK, Hall P, MacInnis RJ, Milne RL, Pharoah PDP, Simard J, Antoniou AC, Easton DF, Michailidou K.

medRxiv. 2024 Feb 13. PMID: 38410445


Carnivore diet a ‘terrible idea’

Some social media influencers are promoting a so-called “carnivore diet” made up almost entirely of animal products such as beef, butter, and eggs.