A process for producing a feedstuff, the process comprising admixing plant leaf pieces with at least one other food ingredient, wherein the plant leaf pieces (i) comprise a total non-polar lipid content of between 5% and 30% by weight on a dry weight basis, (ii) express an exogenous Wrinkled 1 (WRI1) polypeptide and an exogenous diacylglycerol acyltransferase (DGAT), and (iii) have inhibited triacylglycerol (TAG) lipase activity or express an exogenous Leafy Cotyledon 2 (LEC2) polypeptide, or both inhibited TAG lipase activity and express an exogenous LEC2 polypeptide, wherein the plant leaf pieces have an increased total non-polar lipid content relative to a corresponding leaf piece which expresses the exogenous WRI1 polypeptide and the DGAT but which does not have inhibited TAG lipase activity and does not express the LEC2 polypeptide, thereby producing the feedstuff.