Fat accumulation in non-adipose tissue, such as liver and muscle, is associated with reduced insulin sensitivity and cardiovascular disease. Little is known about the dietary determinants and the time course of this ectopic fat accumulation. Therefore the general aim of this project is to develop and validate methodology to follow postprandial hepatic and muscular lipid retention. Proton Magnetic Resonance Spectroscopy (1H-MRS) is a well-established tool for noninvasive quantification of intrahepatic lipids (IHL) and intramyocellular lipids (IMCL). Previous studies have suggested a relatively rapid regulation of IHL and IMCL levels, indicated by changes in these total lipid pools after high fat diets of 3 or 4 days. Although IHL and IMCL levels seem to change rapidly, data on IHL and IMCL levels after a single meal are lacking.