The aim of the paper is to analyse value sharing and food system dynamics of milk, tomato, and cereals food chains, so to explore the agro‐food enterprises capacity to be competitive and sustainable. The paper is based on the functionalist approach of Malassis and the notion of the system of the General Systems Theory. The methodology is aimed at creating a consolidated financial statement for each food chain so to re‐create the chain value and identify how this is shared among the different food chain stages. The analysis is carried out on primary and secondary data : around 2400 financial statements concerning 480 enterprises from 2003 to 2007 and stakeholders’ interviews. Results show that value is usually created in the processing and distribution stages, to the detriment of the primary sector, and that the retail managing practices tend to impose damaging structural changes on farms whose profitability is at times becoming sustainable only thanks to European subsidies. To conclude, there is evidence of inadequate definition of strategic and network alliance along the chain. Competitiveness is still a concept achieved by single food chain stages against others and food chain internal competition entails a declining sustainability of small farms and enterprises.