‘Sustainable’ may be one of the most-used words in food production and marketing, yet, in contrast to terms such as ‘organic’ or ‘Fair Trade’, there is currently no prescribed set of standards or production processes associated with the word. This can be problematic, as the precise meaning behind sustainable food or farming labels can vary considerably according to both marketing intention and consumer perception (Zepeda et al., 2013). Any food labelled as sustainable may therefore be suitable for omnivores, vegetarians or vegans; may be produced in conventional or alternative farming systems; and may encompass any number of attributes, from those that are evidence-based and audited (e.g. carbon footprint), to those that are less tangible but appeal to aesthetic ideals, e.g. ‘eco-friendly’ or ‘humane’.