As one of the most influential figures in nutritional science, Dr. Willett has reshaped global understanding of how diet influences long-term health outcomes.
ST. LOUIS, Dec. 2, 2025 /PRNewswire-PRWeb/ -- The American College of Lifestyle Medicine (ACLM) has awarded Walter Willett, MD, DrPH, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health, the 2025 Dr. Ancel Keys Award. Dr. Willett was honored for his ground-breaking contributions to advancing understanding of the relationship between food and chronic disease.
Dr. Willett received the award at Lifestyle Medicine 2025, ACLM's annual conference in Grapevine, Texas, that was attended in person and virtually by 5,000 clinicians, health leaders and health innovators from some of the nation's largest health systems.
Established in 2019 and only presented every three years, the Dr. Ancel Keys Award honors an individual who is highly respected by their peers as a leader, having made significant contributions to thought, evidence, practice and policy through epidemiological research and the application of mathematical principles with particular emphasis on public health issues and population science.
An influential figure in nutritional science, Dr. Willett has reshaped understanding of how diet influences long-term health outcomes. A physician, epidemiologist, and longtime faculty member at the Harvard T.H. Chan School of Public Health, where he chaired the Department of Nutrition for 25 years, he has guided generations of researchers in evidence-based approaches to disease prevention through nutrition.
Dr. Willett's development of dietary assessment tools—combining questionnaire-based and biochemical methods—helped establish the foundation of modern nutritional epidemiology. Since 1980, his leadership of large-scale cohort studies, including the Nurses' Health Studies I and II and the Health Professionals Follow-Up Study, has produced unparalleled insight into the impact of diet and lifestyle on chronic disease risk among nearly 300,000 participants.
With more than 2,200 scientific papers, multiple books, and the landmark textbook Nutritional Epidemiology to his credit, Dr. Willett is among the most cited scientists in clinical medicine. He was a driving force behind the EAT–Lancet Commission on healthy diets from sustainable food systems, and his work continues to inform global dietary guidelines and shape public health policy aimed at reducing the burden of chronic disease.
A founding member of ACLM's Board of Advisors, Dr. Willett has championed lifestyle medicine since ACLM's inception in 2004, ACLM CEO Susan Benigas said.
"Dr. Willett's contributions have transformed not only how we study the links between diet and disease but also how we apply that knowledge to improve population health," Benigas said. "His research has illuminated the path for clinicians and scientists alike, empowering a new generation to advance the science of nutrition in medicine. It is on the shoulders of leaders like Dr. Willett that the field of lifestyle medicine continues to stand."
The Ancel Keys Award was established by ACLM to memorialize Dr. Keys' Seven Countries Study, a groundbreaking observational cohort study started in 1958, spanning the countries of Greece, Italy, Yugoslavia, the Netherlands, Japan, Finland, and the U.S., which explored the relationship between dietary pattern, lifestyle, biomarkers, and the prevalence of coronary heart disease. The conclusion, which has since inspired countless clinical trials, corroborated other clinical and epidemiological evidence at the time.
Previous recipients of ACLM's Ancel Keys Award include Pekka Puska, MD, PhD, MSocSc, the director and principal investigator of the North Karelia Project, the first public health project worldwide for the prevention of cardiovascular disease mortality, and Henry Blackburn, MD, the project officer for the Seven Countries Study from 1957 to 1972, who succeeded Ancel Keys, upon his retirement, as laboratory director.
About ACLM®
The American College of Lifestyle Medicine (ACLM) is the nation's medical professional society advancing the field of lifestyle medicine as the foundation of a redesigned, value-based and equitable healthcare delivery system, essential to achieving the Quintuple Aim and whole-person health. ACLM represents, advocates for, trains, certifies, and equips its members to identify and eradicate the root cause of chronic disease by optimizing modifiable risk factors. ACLM is filling the gaping void of lifestyle medicine in medical education, providing more than 1.2 million hours of lifestyle medicine education to physicians and other health professionals since 2004, while also advancing research, clinical practice and reimbursement strategies.
Media Contact
Alex Branch, American College of Lifestyle Medicine, 8173072399, [email protected], American College of Lifestyle Medicine
SOURCE American College of Lifestyle Medicine
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