IN THE control of the concentration of blood cholesterol the diet clearly has a marked and ubiquitous effect, but the picture differs in various species. Man does not compare with the rabbit and the chick in sensitivity to exogenous cholesterol, but his response to total fats in the diet appears to be greater.* Obviously, quantitative information on the effect of the diet on the blood cholesterol level in man must be sought from man himself.
Experiments on this problem in man generally have several defects. The studies reported so far have largely ignored the important factor of age 7 and have been limited to a few weeks or months of drastic change from previous lifelong subsistence on the relatively high-fat diet that is almost universally used in the United States at the present time.
The present paper reports findings on clinically healthy men in Naples, where the habitual diet, like