Lefevre Michael, Champagne Catherine M, Tulley Richard T, Rood Jennifer C, Most Marlene M
Division of Functional Foods Research, Pennington Biomedical Research Center, Baton Rouge, LA 70808-4124, USA.
Am J Clin Nutr. 2005 Nov;82(5):957-63; quiz 1145-6. doi: 10.1093/ajcn/82.5.957.
Although reductions in total and saturated fat consumption are recommended to reduce the risk of cardiovascular disease, individual variability in plasma lipid responses exists.
Our aim was to determine the effect of adiposity and insulin resistance on the lipoprotein response to diets lower in total and saturated fat than the average American diet (AAD).
A randomized, double-blind, 3-period crossover controlled feeding design was used to examine the effects on plasma lipids of 3 diets that differed in total fat: the AAD [designed to contain 38% fat and 14% saturated fatty acids (SFAs)], the Step I diet (30% fat with 9% SFAs), and the Step II diet (25% fat with 6% SFAs). The diets were fed for 6 wk each to 86 free-living, healthy men aged 22-64 y at levels designed to maintain weight.
Compared with the AAD, the Step I and Step II diets lowered LDL cholesterol by 6.8% and 11.7%, lowered HDL cholesterol by 7.5% and 11.2%, and raised triacylglycerols by 14.3% and 16.2%, respectively. The Step II diet response showed significant positive correlations between changes in both LDL cholesterol and the ratio of total to HDL cholesterol and baseline percentage body fat, body mass index, and insulin. These associations were largely due to smaller reductions in LDL cholesterol with increasing percentage body fat, body mass index, or insulin concentrations. Subdivision of the study population showed that the participants in the upper one-half of fasting insulin concentrations averaged only 57% of the reduction in LDL cholesterol with the Step II diet of the participants in the lower half.
Persons who are insulin resistant respond less favorably to Step II diets than do those who are insulin sensitive.
尽管建议减少总脂肪和饱和脂肪的摄入量以降低心血管疾病风险，但个体血浆脂质反应存在差异。
我们的目的是确定肥胖和胰岛素抵抗对脂蛋白对低于美国平均饮食（AAD）的总脂肪和饱和脂肪饮食的反应的影响。
采用随机、双盲、3期交叉对照喂养设计，研究3种不同总脂肪含量的饮食对血浆脂质的影响：AAD（设计含38%脂肪和14%饱和脂肪酸[SFA]）、第一步饮食（30%脂肪，9% SFA）和第二步饮食（25%脂肪，6% SFA）。每种饮食以维持体重的水平，对86名年龄在22 - 64岁的自由生活健康男性各喂养6周。
与AAD相比，第一步和第二步饮食分别使低密度脂蛋白胆固醇降低6.8%和11.7%，高密度脂蛋白胆固醇降低7.5%和11.2%，甘油三酯升高14.3%和16.2%。第二步饮食反应显示，低密度脂蛋白胆固醇变化以及总胆固醇与高密度脂蛋白胆固醇之比的变化与基线体脂百分比、体重指数和胰岛素之间存在显著正相关。这些关联主要是由于随着体脂百分比、体重指数或胰岛素浓度增加，低密度脂蛋白胆固醇降低幅度较小。对研究人群进行细分显示，空腹胰岛素浓度处于上半部分的参与者，其低密度脂蛋白胆固醇降低幅度平均仅为下半部分参与者采用第二步饮食时降低幅度的57%。
胰岛素抵抗者对第二步饮食的反应不如胰岛素敏感者。
