Its my feeling that you need to be! both from a point of view of “saving the world” and from the point of view of satisfying your customers moral desires. The introduction of the lifecycle concept in this argument is very important because a partial analysis can miss larger hidden differences if all impacts are not determined.
This article by IUFoST is a good place to start understanding the issues and the practices.
(click image for full story online)
The article outlines a range of issues such as Life Cycle Assessment, global warming, eutrophication, acidification, abiotic resource use, pesticide use/ecotoxicity, land use, Water use and Carbon Footprint of food and interaction with other impacts, before focussing on food processing.
It covers the process based approach, assessment boundaries, mass balance, emissions and co-products and highlight the difficulty of assessing complex foods. The paper gives information and links on the sources of data and provides some data comparing the carbon footprints of food.
A final section shows how the kind of information given here can be used to support decisions and actions in many areas.