XX CONTENTS 



VI. The Occurrence of Lipids in the Animal as a Whole (continued) 



b. The Site of Conversion of Carbohydrate to Fat 540 



c. The Mechanism of the Transformation of Carbohydrate to Fat. . 541 



d. The Nature of the Fat Synthesized from Carbohydrate 545 



(3) Protein as a Source of Body Fat 546 



a. Balance Experiments as Proof of the Conversion of Protein to Fat 546 



b. Respiration Experiments as Proof of the Conversion of Protein to 



Fat 548 



c. Proof of the Conversion of Proteins and Amino Acids to Fat, 



Based upon the Formation of Carbohydrate 549 



(a) The Formation of Glycogen or Glucose 550 



a'. Experiments with Protein 550 



b'. Experiments with Amino Acids 551 



(b) Respiration Experiments as Proof of the Conversion of Pro- 



tein to Carbohydrate 561 



4. The Lipid Content and Composition of the Animal as a Whole 553 



(1) Methods for Determining the Lipid Content of Animals, Including 



Man 553 



a. Direct Analyses 553 



b. Indirect Methods for the Estimation of Body Fat 553 



(a) The Use of "Standard" Weight Tables 553 



(b) The Use of Subcutaneous Fat Estimates 554 



a'. Skinfold Measurements 555 



b'. Fat-Skeleton-Muscle Analyses 556 



c'. Roentgenograms 556 



d'. Direct Measurement of the Thickness of the Subcutaneous 



Layer 557 



(c) The Use of Density Measurements 557 



(d) The Use of Body Water for the Determination of Body Fat. 559 



a'. Test Solutes for the Determination of Water 559 



b'. Formula for the Calculation of Fat Content from Body 



Water Data 563 



(e) The Use of Fat-Soluble Indicators 565 



(2) The Normal Fat Content of Man and Animals 565 



(3) The Normal Composition of Animal Fats 567 



(4) The Distribution and Composition of the Lipids in the Storage De- 



pots and in the Several Organs 568 



a. The Normal Distribution of Lipids 568 



b. The Comparative Lipid Composition of Different Tissues 568 



(5) Factors Altering the Distribution, Content, and Composition of Tis- 



sue Lipids 573 



a. The Effect of Age 573 



(a) The Distribution of Tissue Lipids as Affected by Age 573 



(b) The Content of Tissue Lipids as Affected by Age 573 



(c) The Composition of Tissue Lipids as Affected by Age 575 



b. The Effect of Embryonic Development 579 



c. The Effect of Sex 579 



(a) The Effect on Total Fat 579 



