Nɛ-Carboxymethyl-lysine (CML) is a prominent advanced glycation end-product which is not only found in vivo but also in food. It is known that a percentage of the dietary CML (dCML) is absorbed into the circulation and only partly excreted in the urine. Several studies have tried to measure how much dCML remains in tissues. However obstacles to interpreting the data have been found.