David L. Katz

David L. Katz (born February 20, 1963) is an American physician, nutritionist and writer. He was the founding director of the Yale-Griffin Prevention Research Center that was founded at Griffin Hospital in 1998. Katz is the founder and chief executive officer of Diet ID and True Health Initiative. He is a notable advocate of plant-predominant diets.

Career

Katz completed his internal medicine training at Norwalk Hospital and his preventive medicine residency at Yale School of Medicine. He joined the faculty of the Yale School of Medicine, where he held appointments including Associate Clinical Professor of Epidemiology and Public Health and Associate Clinical Professor of Medicine.

Katz served as founding director of Yale University’s Yale-Griffin Prevention Research Center from 1998 to 2019. The Center was established with a grant from the Centers for Disease Control and Prevention to the Yale School of Public Health. During Katz’ tenure as director, the center received a total of $40 million in funding. He stepped down as director on October 1, 2019.

He served as Chief Science Officer of NuVal, LLC, from 2008 to 2018, and was the inaugural editor-in-chief of the journal Childhood Obesity for five years. He was President of the American College of Lifestyle Medicine from 2014 to 2016.

In 2015, Katz founded True Health Initiative, a 501c3 non-profit. In 2019, Katz became chief executive officer of Diet ID, a nutrition assessment company he founded. He was also among LinkedIn's original 150 "Influencers" and wrote a weekly preventive medicine column for the New Haven Register for about 25 years beginning in 1996, syndicated through The New York Times.

In March 2020, Katz published opinion pieces in The New York Times and The Wall Street Journal advocating risk-stratified protection rather than broad lockdowns during the COVID-19 pandemic. He promoted a public health approach of "total harm minimization" and general health promotion, volunteered during the New York City surge, and briefly provided frontline clinical care in a Bronx emergency department.

In May 2020, he testified before the United States Senate Committee on Homeland Security and Governmental Affairs on the federal pandemic response. He was invited to the White House that year to discuss pandemic policies but declined. Katz is a co-signatory of the Great Barrington Declaration. His later pandemic commentary in the American Journal of Health Promotion was named among the journal's "Best Papers" of 2024.

Research Katz has been credited with developing evidence mapping, a method for systematically characterizing scientific literature. His research focuses on nutrition, preventive medicine, chronic disease prevention, and lifestyle medicine.

In 2019, Katz published a paper in Advances in Nutrition on the health and environmental implications of predominantly whole-plant diets. He also co-authored a 2024 review in Mayo Clinic Proceedings: Innovations, Quality & Outcomes examining the evidence for the six pillars of lifestyle medicine. His 2014 paper in Annual Review of Public Health, "Can We Say What Diet is Best for Health?", was among the journal's most-downloaded papers and was discussed by The Atlantic.

Katz developed and patented Diet ID, a digital dietary assessment tool based on dietary pattern recognition. A 2023 study in Current Developments in Nutrition found moderate-to-strong correlations between Diet ID and traditional dietary assessment methods. He has also proposed the "fixed-quality, variable-type" (FQVT) approach to dietary intervention research.

Plant-based nutrition

Katz is an advocate of diets that are "plant-predominant" such as vegan, vegetarian, pescetarian and the Mediterranean diet. He has stated that the "best diets for human health are plant-predominant, whole food plant, predominant, so all of us should be eating plenty of plant foods".

Katz is not a vegan in his personal life but says he eats plant-based most of the time and gave up eating red meat for ethical and environmental reasons. He has lectured on plant-based nutrition at SUNY Downstate Medical Center and for Plant-Based Health Professionals UK.

His book How to Eat: All Your Food and Diet Questions Answered, co-authored with food journalist Mark Bittman, was published in 2020. It promotes a plant-predominant diet.

Awards and honors Katz has received honorary doctorates from the University of Bridgeport, Quinnipiac University, and Bastyr University, and has repeatedly been a supported nominee for U.S. Surgeon General. Recent recognitions include a Lifetime Achievement Award from the Doctors' World Gala (2023) , the President's Award from the American College of Lifestyle Medicine (2024), induction into Sigma Xi (2025), and the Leadership Award from the Integrative Healthcare Symposium (2026). He was a 2019 James Beard Foundation Award nominee in health journalism.

Personal life Katz is married to Catherine (Sananès) Katz and has five children.