The urinary excretion of six methylated ribonucleosides was measured in a case of anorexia nervosa during the first eight weeks of therapy. Four phases can be distinguished. Highly elevated values are found in a clearly catabolic situation. Immediately after onset of therapy when catabolism is stopped but nutrition still inadequate the excretion of RNA-catabolites is lowered markedly. As soon as normocaloric nutrition is reached after two weeks, a short but clearcut peak-excretion can be observed. Finally, the excretion of methylated RNA-catabolites is stabilized on an intermediate level after three to six weeks, when nutrition is constantly normocaloric and weight continues to increase linearly.
