A process for the branching of saturated and/or unsaturated fatty acids and/or alkyl esters thereof comprises subjecting the fatty acids and/or alkyl esters to a skeletal isomerization reaction using a catalyst comprising a crystalline porous structure having incorporated therein a metal to form metal sites on said catalyst and isolating branched fatty acids, alkyl esters thereof, or mixtures thereof, from a reaction mixture obtained by said skeletal isomerization reaction. The catalyst used in the isomerization reaction is preferably a zeolite catalyst containing metal sites of a Group VIII metal. The process produces a mixture of fatty acids and/or alkyl esters that contain significant quantities of branched molecules.