Kato, H. (Dept. of Statistics, Atomic Bomb Casualty Commission, 5–2 Hijiyama Park, Hiroshima, Japan 730), J. Tilotson, M. Z. Nichaman, G. G. Rhoads and H. B. Hamilton. Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: Serum lipids and diet. Am J Epidemiol 97: 372–385, 1973.—The relationship between serum lipids, i.e., serum cholesterol and casual serum triglycerides, and dietary intake was investigated in men of Japanese ancestry resident in Japan, Hawaii and California as part of a large scale comparative study of cardiovascular diseases. The study provided a good opportunity for such an effort because dietary intake patterns varied remarkably among the three cohorts although their genetic background is essentially the same. Serum cholesterol showed a positive regression with dietary intake of saturated fat, animal protein, and dietary cholesterol. The regression with saturated fat was more strongly observed in Japan where average body weight and serum cholesterol levels are considerably lower than in the more Americanized cohorts, and where average dietary fat intakes are roughly 40% of those recorded in Hawaii and California. Interestingly, the relationship between saturated fat intake and serum cholesterol was stronger in the groups with lower relative body weight in both Japan and Hawaii. Serum cholesterol was negatively associated with complex carbohydrate intake, but no association was observed with simple carbohydrate. Regression of nutrient variables with casual triglyceride measurements was weak, although consistently negative with the calorie/weight index.