Extract: The acute effects of a cholesterol- and saturated fat-rich meal on plasma lipids and lipoproteins and on platelet aggregation were studied in 10 normolipidemic subjects after 12 h of fasting (before the meal) as well as 3.5 h after the meal. The constituents of the meal comprised foods normally consumed in Israel, with a total caloric intake of 1140 kcal (53% fats, 26% carbohydrates, and 21% proteins), 950 mg cholesterol and P/S ratio of 0.15. Plasma cholesterol and triglyceride levels were elevated by 18.6 and 83.8%, respectively, after the meal. Elevated concentrations of protein, cholesterol and triglycerides in all lipoprotein fractions were noted. Collagen-, but not ADP-, induced platelet aggregation was significantly increased in all subjects. There was a minor elevation in plasma apo A-I and apo B concentrations. We conclude that a high cholesterol/high saturated fat meal is atherogenic, as demonstrated by the plasma lipid and lipoprotein pattern and by increased platelet aggregation.(author)