A nutritional fat or oil-based composition for increasing HDL cholesterol, decreasing LDL cholesterol and decreasing the LDL/HDL cholesterol ratio in human plasma is described. The composition typically includes at least 1% by weight myristic acid esterified at the sn-2 position in triglyceride molecules, includes between 10% and 40% by weight linoleic acid, and further includes between 30% and 65% by weight oleic acid and between 15% and 40% by weight total saturated fatty acids. The ratio of sn-2 myristic acid to sn-2 palmitic acid is typically greater than 1:1 and the sum of weight percentages for saturated, monounsaturated and polyunsaturated fatty acids equals 100%. In desirable cases, the composition is substantially cholesterol-free.