In recent years, non-invasive methods like proton magnetic resonance spectroscopy (1H-MRS) have been developed for quantifying lipid content in skeletal muscle and the liver, and were frequently applied by us and others. These measurements can be combined with other Magnetic Resonance techniques to investigate hepatic ATP- and Pi concentrations, determined by phosphorus magnetic resonance spectroscopy (31P-MRS). Furthermore, it has been shown that ATP- and Pi concentrations are lower in subjects with type 2 diabetes mellitus, who are characterized by hepatic lipid accumulation and hepatic insulin resistance. It has been suggested that a decreased ATP and Pi concentration may be an underlying factor for hepatic lipid accumulation.