The PURE Study on Dietary Fat and Carbohydrates (2017)

The PURE study's 135,000-person, 18-country analysis delivered a definitive blow to low-fat dogma: high carbohydrate intake increased mortality risk by 28%, while every type of dietary fat—including saturated fat—lowered it. This directly contradicts the advice of the World Health Organization's 2015 guideline that still advocates limiting total fat to 30% of calories, making PURE the most empirically grounded challenge to conventional dietary wisdom. The controversy erupted because the findings were not merely nuanced but fundamentally oppositional to decades of public health messaging, and subsequent meta-analyses have confirmed that replacing saturated fat with refined carbs raises cardiovascular risk. The study's scale and geographic diversity also outperforms #7 (the PACE trial) in methodology, yet its results remain marginalized by entrenched institutional guidelines.