Walter C. Willett

New Capabilities

Senior researcher and department leader

For seven decades, nutrition scientists have battled over whether cutting carbohydrates or cutting fat is the path to a healthy heart. A new Harvard study tracking nearly 200,000 Americans over 30 years offers a different answer: what matters most is not whether you reduce carbs or fat, but whether the foods you choose are whole grains, vegetables, and plant proteins—or processed alternatives and red meat.

Updated Feb 17