← Home
Diet Doctor Podcast · April 11, 2022 · 42m
The Challenge of Nutrition Science — Why It's So Hard to Get Straight Answers
Dr. Scher explains why nutrition science is uniquely difficult — confounding variables, healthy user bias, food frequency questionnaire limitations, and why randomized controlled trials of diet are nearly impossible to run at scale.
Highlights
•
Most nutrition evidence is observational — which can only show correlation, not causation
Scher: 90%+ of nutrition studies are observational (cohort studies, case-control studies, ecological studies). These can identify associations but cannot prove causation. Confounding variables — exercise, smoking, socioeconomic status — are nearly impossible to fully adjust for.•
Nutrition science requires epistemic humility — strong claims require strong evidence, and nutrition has weak evidence
Scher: the strength of conviction in nutrition debates is inversely proportional to the strength of the evidence. With mostly observational data, reasonable uncertainty should be the default position, but tribal loyalties drive overconfident claims on all sides.