Changes in plasma lipid and lipoprotein fractions after alteration in dietary cholesterol, polyunsaturated, saturated, and total fat in free-living normal and hypercholesterolemic children.

To assess the effects of dietary cholesterol and the amount and type of fat on plasma lipid and lipoproteins, nutrient intakes were altered sequentially over 15 months in 11 normal children and 12 children with heterozygous familial hypercholesterolemia. After a 3-month base-line assessment period, on an ad libitum diet, the following diets were given sequentially for three months each: dietary cholesterol greater than 450 mg/day, total fat less than 35% of total calories, and polyunsaturated fat to saturated fat ratio (P/S) greater than 1.5 (diet 1); dietary cholesterol less than 160 mg/day, total fat less than 35% total calories and P/S greater than 1.5 (diet 2); dietary cholesterol less than 160 mg/day, total fat 40% total calories P/S = 1 (diet 3), and dietary cholesterol greater than 450 mg/day total fat greater than 40% total calories, P/S less than 0.04 (diet 4). In normal and familial hypercholesterolemic children the high dietary P/S ratio lowered total and low-density lipoprotein cholesterol in the presence of high dietary cholesterol; sharp reductions in dietary cholesterol lowered the total and low-density lipoprotein cholesterol slightly in familial hypercholesterolemia subjects when P/S was high. High-density lipoprotein cholesterol was not affected by large changes in dietary cholesterol or amount or type of fat. Sustained dietary alteration which significantly lowers total and low-density lipoprotein cholesterol with commercially available products is achievable and practical in free-living children.