Diet-Heart Hypothesis

Rodent 'high-fat diet' research is systematically misleading because the model used is actually high sugar plus industrial seed oil, not dietary fat. When subjects with diabetes or obesity genuinely eliminate carbohydrates and switch to high-fat diets, blood fat levels drop and all metabolic markers improve dramatically. Ancel Keys' diet-heart hypothesis — that dietary saturated fat elevates blood cholesterol which causes heart disease — is largely incorrect at every link in the chain. Dietary cholesterol does not meaningfully change blood cholesterol because the liver adjusts its own production to compensate, maintaining tight homeostasis. The appearance that dietary fat causes insulin resistance arises specifically when fat is consumed alongside refined carbohydrates, not in isolation.