The Planetary Health Diet 2 | Walter Willett, MD, DrPH

What does it take to eat for the health of humans and the planet? In this episode of The Ty Beal Show, Dr. Walter Willett, the world’s most cited nutritionist, gives a sneak peek at the upcoming 2025 EAT-Lancet Commission and provides his take on ultra-processed foods and seed oils.

From his family farm in Michigan to leading Harvard's Department of Nutrition for 25 years, Dr. Willett shares the journey that led him to pioneer nutritional epidemiology. At the center of this conversation is the planetary health diet—a flexible framework to address human and planetary health.

What you'll discover:

• The 2025 EAT-Lancet Commission's updated recommendations (releasing October 3rd)
• How to adapt the planetary health diet from vegan to omnivore preferences
• The limitations of the NOVA ultra-processed food framework
• The health effects of seed oils like soybean and canola oil
• How Dr. Willett's trans-fat research transformed American food policy

Dr. Willett addresses the seed oil controversy with decades of research, explaining why these oils have helped reduce heart disease rates since the 1950s. He also reveals why the real drivers of obesity aren't seed oils but sugar-sweetened beverages and refined starches, and how the planetary health diet balances individual health with global sustainability and equity.

Find Dr. Walter Willett's research at Harvard T.H. Chan School of Public Health and learn more about the EAT-Lancet Commission.

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