Abstract How research impact is defined and evaluated is much-debated at research policy level. Offering one avenue for capturing societal research impact, altmetrics are proposed as quantitative indicators providing a measure of the reach and attention that a research output, such as a peer-reviewed paper, is receiving online. Eighty publicly-funded food researchers participated in an online mixed-methods engagement study. The analytical framework of sensemaking was used to explore participants’ views of altmetrics as a threat or opportunity for their perceived professional identities. The identities important to our participants included ensuring rigour and quality in knowledge production; communicating and engaging with non-academic audiences; and bringing about tangible and meaningful changes in society. While an appetite for changes to research evaluation was apparent in our study, altmetrics was perceived to introduce a number of different threats as well as opportunities to the academic identity, which will influence its potential uptake and use.