The influence of dietary fat on the glyceride structure of animal fat

Summary and Conclusions In order to determine the glyceride structure of a representative mammal and bird, rats and chicks were raised on an essentially fat‐free ration, and the percentage of saturated triglycerides in their neutral fat was determined by an isotope dilution procedure. In order to determine the influence of ingested fat, second groups were fed the fat extracted from the animals in the first group, at the 20% level. Third groups were fed cottonseed oil, which has “even” distribution of its fatty acid. It was found that: The glyceride structure of endogenous rat fat conforms to the “random” type distribution. Ingested fat appears to be digested and resynthesized by the rat according to “even” type distribution, or, at least, in a manner which tends to distribute the fatty acids. Chicks tend to produce simple or “mono‐acid” glycerides (8) in which the percentage of trisaturated glycerides is higher than expected for random distribution. It is suggested that the findings can be explained by a selective affinity of the esterifying enzyme system for saturated acids and for the 1‐position on the glyceride molecule. In the case of the bird its higher body temperature may increase the speed of the reaction on the 2‐ and 3‐positions of the glycerol sufficiently to account for an increase in tri‐saturated glycerides above that required by random distribution.