This study's purpose was to evaluate the fasting human plasma lipid and lipoprotein responses to dietary beef fat (BF) by comparison with coconut oil (CO) and safflower oil (SO), fats customarily classified as saturated and polyunsaturated. Nineteen free-living normolipidemic men aged 25.6 +/- 3.5 yr consumed centrally-prepared lunches and dinners of common foods having 35% fat calories, 60% of which was the test fat. The test fats were isocalorically substituted, and each fed for five weeks in random sequences with intervening five weeks of habitual diets. Plasma total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) concentrations among individuals follows the same relative rank regardless of diet. Triglycerides (TG) concentrations among individuals also maintain their relative rank regardless of diet but in a different order from that of the cholesterols. Plasma TC, HDL-C, and LDL-C responses to BF were significantly lower and TG higher than to CO. As compared to SO, BF produced equivalent levels of TG, HDL-C, and LDL-C and marginally higher TC. Thus, the customary consideration of BF as "saturated" and grouping it with CO appears unwarranted.