Sensitivity to anorexia is higher in weanlingrats (21-22 days old) than later on, so to avert theconfounding effects of impaired weight gain, we waited tostart the ketogenic diet until the rats were 50 to 52 days old.These parameters affecting the magnitude and duration ofketosis have not been studied in detail so their thresholds tomaintain (or prevent) prolonged ketosis are presentlystill unknown.