Consumers are becoming increasingly aware of dietary issues and are demanding that food is labelled effectively with compositional information. In the past 20 years major changes have taken place in beef production, in particular the greater use of young bulls and the introduction of genes from several continental breeds, which have the potential of producing leaner meat. The current standard reference, McCance and Widdowson's ‘The Composition of Foods’ was last revised over 10 years ago, so this trial was set up in collaboration with the Ministry of Agriculture, Fisheries and Food to provide up-to-date estimates of the chemical composition of beef.