Individual Variation Is Substantial
Statement
Optimal diet varies by genetics, microbiome, activity
level, health status, and preferences --- no single diet is universally
best
Why it matters
Prevents dogmatic diet recommendations --- what works
for one person may fail or harm another
Why Foundational
Foundational because variation magnitude is empirically demonstrated — PREDICT 1 (n=1,000+, identical meals) found coefficient of variation 103% for fat, 68% for glucose, 59% for insulin responses; the Zeevi study (n=800, 47,000 meals) confirmed carbohydrate content alone poorly predicts glucose response. Optimal diet varies by genetics, microbiome, activity level, health status, and preferences — no single diet is universally best. Prevents dogmatic recommendations: what works for one person may fail or harm another.