Variation in Composition of Serum Free Fatty Acids with Dietary Change Under Isocaloric Conditions

Abstract

The fatty acid pattern of the serum free fatty acids was studied and appears to be a reliable and effective aid in monitoring short term dietary adherence for either a saturated or polyunsaturated 30 per cent fat diet under isocaloric conditions. Changes in P:S (polyunsaturated fatty acids to saturated fatty acids) ratio occur within seventy-two hours after beginning an “unsatyrated” fat diet (P:S ratio 3:1), and remain above 1.0 throughout the period of dietary adherence. Within one week of resuming a saturated fat diet (P:S ratio 1:3), the P:S ratio of the serum free fatty acids returns to its former level. These findings strongly suggest that the serum free fatty acids are rapidly and significantly influenced by the composition of ingested dietary fat in the absence of weight change.