Summary: Controlled feeding study in 32 Dutch volunteers, each completing 3 trials alternating a low- and a high-dietary-cholesterol (egg-based) diet, classifying participants as consistent hypo- or hyperresponders by serum-cholesterol change. Responsiveness correlated positively with the HDL2-cholesterol and total-cholesterol rise on the high-cholesterol diet, but did NOT correlate with habitual cholesterol intake or body weight — hypo/hyperresponder status could not be predicted from lifestyle. Outcome is a surrogate endpoint (serum cholesterol response).
Relevance: Foundational primary establishing a stable, lifestyle-independent inter-individual hypo-/hyperresponder classification — the empirical basis for the pro-egg-for-some argument that population-average LDL response overstates harm for the (unpredictable, but sizeable) hypo-responder subset.