Lipoprotein response to a National Cholesterol Education Program step II diet with and without energy restriction

This study examined the efficacy of a National Cholesterol Education Program (NCEP) step II diet (25% fat with < 7% saturated fat [SFA]) with and without moderate energy restriction. We tested the hypothesis that moderate energy restriction would improve the lipid profile resulting from an isoweight NCEP step II diet. Twenty hypercholesterolemic subjets (10 men and 10 postmenopausal women) consumed the following three controlled diets, each of 4 weeks' duration, as outpatients: (1) high-fat, high-saturated-fat diet to establish baseline lipids and isoweight energy requirements, (2) NCEP step II diet at isoweight energy, and (3) NCEP step II diet with an energy level 15% less than isoweight. The NCEP step II diet at isoweight energy reduced total cholesterol (TC) by 4% (P = .015), high-density lipoprotein cholesterol (HDL-c) by 13% (P < .0001), and HDL2-c by 40% (P < .0001). The TC:HDL-c ratio increased from 4.9 to 5.5 (P < .0001) and was increased in 19 of 20 subjects. Apolipoprotein B (apo B)-containing lipoproteins changed reciprocally: low-density lipoprotein cholesterol (LDL-c) decreased 4% (P = .008) and very-low-density lipoprotein cholesterol (VLDL-c) increased 29% (P < .0001). Apo B levels did not change. Compared with the NCEP isoweight diet the NCEP hypocaloric diet significantly reduced VLDL-c (-9%, P = .014) and apo B (-5%, P = .015). There was an additional reduction in TC (-4%, P = .073) and LDL-c (-4%, P = .126) with no change in HDL-c (P = .807). These data indicate that a NCEP step II diet with energy restriction produces a more desirable lipoprotein response than a NCEP step II isoweight diet. Neither NCEP step II diet improved the TC:HDL-c ratio.