Vital Need of the Body for Certain Unsaturated Fatty Acids Ii. Experiments with High Fat Diets in Which Saturated Fatty Acids Furnish the Sole Source of Energy*

In our studies on the physiological importance of fats to the animal organism (l), we became convinced that progress could be made only when individual fatty acids were used. Even the most simple natural fat is a complex entity. In addition to glycerides of fatty acids, we have the substances collectively called the nonsaponifiable matter. From the present standpoint these may be looked upon as impurities associated with the glycerides of the fatty acids. The glycerides themselves are complex; witness the multiplicity of differing fatty acids, saturated and unsaturated, present, and the possible isomeric arrangements in the glycerol molecule. Only when synthetic fats composed of single fatty acids are used in experimental diets will it be possible to accumulate a body of data which will lead to a better understanding of the Ale played by fats in the animal organism. The present communication is concerned with the role of single saturated fatty acids when vitamin B and, in fact, all the known vitamins are adequately supplied. When single fatty acids were used as the sole source of energy in the diet, certain phenomena akin to those obtained in studies on fat-free diets were manifested (2, 3). There were discovered similarities, but also some vital differences.