Several studies in the pharmaceutic industry validated the extremly valuable application of TD-NMR relaxometry in body composition analysis of mice and rats [1]. Instead of harmful treatment as in chemical analysis or in DEXA, the animal is brought only into magnetic fields comparable to well known clinical MRI, the analysis takes place in a few minutes thus minimizing the effort and stress the animals are subjected to. The animals are awake, unavoidable movements are small as the methodology is optimized and quite forgiving in this respect. The relaxometric TD-NMR method introduced in 2001 has quickly gained market acceptance as a powerful non-destructive and non-invasive tool for characterizing, screening and phenotyping animal models with respect to body composition.