。Thin rat bury fat rat The rats are both 1000 days old,very old for rats.The one on the right was calorie restricted.The one on the left is near death and shows typical signs of old age similar to what happens in humans. Image cited from Clive McCay 1939. • Thin rat bury fat rat • The rats are both 1000 days old, very old for rats. The one on the right was calorie restricted. The one on the left is near death and shows typical signs of old age similar to what happens in humans. • Image cited from Clive McCay 1939