Three controlled feeding experiments in Dutch volunteers (n=94 in the main experiment) varied dietary cholesterol from a baseline of ~100-130 mg/d to ~625-989 mg/d. Serum cholesterol rose 0.50 mmol/L on average, but subjects who were extreme responders in one experiment were retested in follow-up experiments and reproducibly showed the same rank: “hyporesponders” had significantly and consistently smaller serum-cholesterol rises than “hyperresponders” across repeat challenges (reproducibility regression coefficients 0.34-0.53). This is the founding demonstration that hypo-/hyperresponse to dietary cholesterol is a stable, reproducible individual trait in humans (previously shown only in animals), not just noise around one population mean.
relevance_note: Foundational primary for the whole “for whom” thread — establishes that a single population-mean lipid response to dietary cholesterol is the wrong summary statistic, because a real, stable inter-individual split sits underneath it.